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Weather Station Hardware => Davis Instruments Weather Stations => Topic started by: azchrisf on March 24, 2018, 01:00:45 PM

Title: Remote Battery
Post by: azchrisf on March 24, 2018, 01:00:45 PM
I wanted to bounce an idea off you guys for a remote battery pack, kind of like Accurite offers for their systems.
My Anemometer/UV & Solar transmitters are up on top of my chimney, exactly 33 ft (yea!!!) from ground level.

Because I don't want to (and most people don't) get up there to change a battery, the next time maintenance comes due, I would like to solder to the battery terminals, and run wire down the chimney to a remote enclosure containing the batteries in a battery holder that I can easily access when needed.

The only issue I have is what gauge wire to use for ~33 ft for the 123A cells.
Any suggestions or additional ideas?
Title: Re: Remote Battery
Post by: SLOweather on March 24, 2018, 01:31:38 PM
Don't bother trying to solder to the terminals. The SIM board has a jack on it for the Davis size console plug. If you need a plug, you can get a Davis USB console cable from Scaled Instruments (#6627) for $6 plus shipping, and splice it.

As far a gauge, it uses such little current, just about anything would work. Get something black that will resist UV. 18 gauge zip cord would be OK.
Title: Re: Remote Battery
Post by: vreihen on March 24, 2018, 01:38:54 PM
I think that Acu-Rite's remote battery pack uses 30 feet of 22awg.  I made my own for my Acu-Rite with 15 feet of 20awg, because it was what I had on hand.  My $0.02 unless someone else has experience is to see what the voltage drop across 33 feet of 20awg turns out to be.  Per this calculator, it should be negligible:

https://www.calculator.net/voltage-drop-calculator.html?material=copper&wiresize=33.31&voltage=3&phase=dc&noofconductor=1&distance=33&distanceunit=feet&amperes=0.01&x=68&y=18 (https://www.calculator.net/voltage-drop-calculator.html?material=copper&wiresize=33.31&voltage=3&phase=dc&noofconductor=1&distance=33&distanceunit=feet&amperes=0.01&x=68&y=18)

IIRC, there is an external power connector on the wireless VP2 transmitter's logic board.  Can it run from a wall wart with a long cable?????
Title: Re: Remote Battery
Post by: johnd on March 24, 2018, 02:22:05 PM
Can it run from a wall wart with a long cable?????

Yes, the standard Davis 5v adapter should be fine. If you use this then there's obviously not too much worry about voltage drop. Another option would be to get the Davis USB power cable and splice your own cable in the middle, obviously taking due care to polarity and to _properly_ weatherproofing any joint exposed to the weather.
Title: Re: Remote Battery
Post by: azchrisf on March 25, 2018, 03:12:12 AM
Thanks guys - SLO, you had a great idea with the AC plug in the units instead of soldering.
Title: Re: Remote Battery
Post by: johnd on March 25, 2018, 03:41:26 AM
Can it run from a wall wart with a long cable?????

Yes, the standard Davis 5v adapter should be fine. If you use this then there's obviously not too much worry about voltage drop. Another option would be to get the Davis USB power cable and splice your own cable in the middle, obviously taking due care to polarity and to _properly_ weatherproofing any joint exposed to the weather.
Title: Re: Remote Battery
Post by: johnd on March 25, 2018, 03:41:54 AM
Can it run from a wall wart with a long cable?????

Yes, the standard Davis 5v adapter should be fine. If you use this then there's obviously not too much worry about voltage drop. Another option would be to get the Davis USB power cable and splice your own cable in the middle, obviously taking due care to polarity and to _properly_ weatherproofing any joint exposed to the weather.

Title: Re: Remote Battery
Post by: EA1EF on March 25, 2018, 03:38:34 PM
A 18650 lithium battery should work fine...
Title: Re: Remote Battery
Post by: johnd on March 25, 2018, 03:52:06 PM
A 18650 lithium battery should work fine...

Yes, certainly. But why bother if it's feasible to use an AC mains adapter?
Title: Re: Remote Battery
Post by: EA1EF on March 26, 2018, 09:12:40 AM
1 because the power consuption are a lot

2 because can appear ground problems, its not good idea wires linkend inside home and outside home, specially when are metallic mast... aditional protections will be recommended

Title: Re: Remote Battery
Post by: azchrisf on March 26, 2018, 09:15:37 AM
Yeah no way I'm using AC power - too many issues, besides which, there is no AC plug at the chimney.
So remote battery pack it is.
Title: Re: Remote Battery
Post by: dalecoy on March 26, 2018, 10:33:10 AM
1 because the power consuption are a lot

Compared to the total environmental cost of batteries?
Title: Re: Remote Battery
Post by: SLOweather on March 26, 2018, 11:26:34 AM
One other thing you have the option for.

Rather than remoting a CR123, opt for a larger pack. 3 D cells would run that station for years, I'll bet. I think kobuki or someone here is doing that.

Yeah no way I'm using AC power - too many issues, besides which, there is no AC plug at the chimney.
So remote battery pack it is.
Title: Re: Remote Battery
Post by: azchrisf on March 26, 2018, 11:27:45 AM
SLO,

Great idea. What about some 18650 cells?
Title: Re: Remote Battery
Post by: SnowHiker on March 26, 2018, 05:49:24 PM
Something else to possibly consider: BOTH the battery (CR123A or multiple C or D cells) and/or the AC-Adapter can be "remoted" (30-40 ft) via/thru that AC-plug into the ISS.
I guess the question would be if it's worth it.  Having the battery backup would provide power for extended power outages but, unless possibly the power was out all night, the supercap should provide adequate backup.  Also, if a fresh battery is put in the ISS, and AC power is used, the lithium 123 should last many years, making it more likely the ISS will need to be taken down for other maintenance before the battery goes without having to remote it.

On the other hand, while I know CR123 batteries are supposed to have a shelf-life of many years, and I think aren't real susceptible to corrosion and leakage, I'd still be a little wary of leaving it in for years without periodically being able to periodically check it.
Title: Re: Remote Battery
Post by: SnowHiker on March 26, 2018, 06:00:02 PM

 Having the battery backup would provide power for extended power outages but, unless possibly the power was out all night, the supercap should provide adequate backup. 
Then, I could be thinking wrong.  Isn't plugging the connector of the unplugged power adapter into the ISS supposed to drain the supercap, meaning it won't provide adequate backup if power failed?
Title: Re: Remote Battery
Post by: SnowHiker on March 26, 2018, 08:16:51 PM
Continuing to think out loud...

I'm back to thinking that the original idea of soldering the battery terminals to use a remote battery just as backup may be best.  It'll allow the ISS to continue to run on solar power the majority of the time, just using the battery as backup as originally intended, and most likely be somewhat safer than running wires outside hooked up to ac inside.  It seems not much more work would be required than whatever soldering and splicing is going to be required anyway, especially if it was decided that battery backup along with the ac/dc power adapter was desired.

I'm not sure how hooking up the battery to the jack on the ISS would work, but unless someone can say that it wouldn't interfere with the normal operation of the solar panel and supercap, but it appears that it would, I would go with azcrisf's original idea. 

Title: Re: Remote Battery
Post by: Mattk on March 26, 2018, 08:59:21 PM
Continuing to think out loud...

I'm back to thinking that the original idea of soldering the battery terminals to use a remote battery just as backup may be best.
No not the best idea but you could make an external battery pack adapter which clips into where the battery fits, no soldering and easily replaceable

Quote
....t'll allow the ISS to continue to run on solar power the majority of the time, just using the battery as backup as originally intended, and most likely be somewhat safer than running wires outside hooked up to ac inside....
The ac bit isn't really relevant as it's 5v dc output and as far as backup goes then one would drive the ISS via 5-6 volts in the dc jack from a battery or convertor and be maintaining this battery via ac trickle charge.

Quote
....I'm not sure how hooking up the battery to the jack on the ISS would work..
Works perfectly

Quote
....but unless someone can say that it wouldn't interfere with the normal operation of the solar panel and supercap, but it appears that it would....
In fact in remote installations with the ISS installed in secure enclosures just throw the solar panel away and forget about the supercap, typically 12V/5V convertor to the ISS external power jack, CR123 gets tossed in lieu of better backup and the ISS will basically never have downtime from a power related failure. 

Title: Re: Remote Battery
Post by: SnowHiker on March 26, 2018, 09:17:38 PM
If that's what the OP intends; run the ISS solely from an external battery, then it may work fine.  That wasn't what I thought he had in mind, but I guess it's an option.  Removing the supercap completely would avoid some future maintenance.
Title: Re: Remote Battery
Post by: EA1EF on March 27, 2018, 06:14:26 PM
a good option, as seen and read here, are buy a cabled version,  we use a small USB power battery with UPS capabilities (with simultaneous charge and discharge) as TECKNET models


we love the option 5v USB power UPS because source both console and the PC Stick with same power supply 5v 2A its a cheap, low power, clean, and safe solution



Title: Re: Remote Battery
Post by: azchrisf on March 30, 2018, 11:07:47 AM
OK, I want to make sure this is clear:

The power jack for DC input can be connected to a CR123A battery, leaving the battery socket empty, and it will work as if the battery was in the socket and used if/when the capacitor discharges, correct? The solar panel will still be connected of course.

If that is correct then it seems all the inputs (battery, solar & DC input) all just power the capacitor, and the unit runs directly off the capacitor at all times?

Just want to make sure we're on the same page.
Title: Re: Remote Battery
Post by: dalecoy on March 30, 2018, 12:00:49 PM
it seems all the inputs (battery, solar & DC input) all just power the capacitor, and the unit runs directly off the capacitor at all times?

Not correct.
Title: Re: Remote Battery
Post by: azchrisf on March 30, 2018, 01:04:51 PM
Well then I need to use a Battery Eliminator to do a remote battery pack LOL...all this talk of using the DC jack on the board doesn't do what I want - it would override the solar panel and the cap.
Title: Re: Remote Battery
Post by: dalecoy on March 30, 2018, 01:47:56 PM
Well then I need to use a Battery Eliminator to do a remote battery pack LOL...all this talk of using the DC jack on the board doesn't do what I want - it would override the solar panel and the cap.

Not correct.  The jack has no "override the solar panel and the cap" function.  It just provides a convenient way to connect an additional voltage (power) source to the ISS.

What was it that you wanted to do?
Title: Re: Remote Battery
Post by: SnowHiker on March 30, 2018, 01:55:06 PM

Not correct.  The jack has no "override the solar panel and the cap" function.  It just provides a convenient way to connect an additional voltage (power) source to the ISS.

What was it that you wanted to do?
Then when you want to quickly discharge the supercap, why do you plug in the unpowered adapter to it if it doesn't affect it?
Title: Re: Remote Battery
Post by: SnowHiker on March 30, 2018, 02:12:18 PM
Well then I need to use a Battery Eliminator to do a remote battery pack LOL...all this talk of using the DC jack on the board doesn't do what I want - it would override the solar panel and the cap.
It seems so.  If you used the jack on the board, when a power outage occurred it appears the supercap would drain quickly, not providing adequate backup for prolonged outages, even if it doesn't completely override the panel and cap.

Otherwise it seems if the jack was used under normal operation the station would continually be running on house current from the adapter, basically bypassing the panel and cap.

So yes, it appears your original idea was best for what you are asking.
Title: Re: Remote Battery
Post by: dalecoy on March 30, 2018, 03:18:52 PM
Then when you want to quickly discharge the supercap, why do you plug in the unpowered adapter to it if it doesn't affect it?

I don't.

Have you actually done that, and checked the results?  It doesn't work (at least on recent models).

And what is the specified maximum voltage rating of the supercap?  [Hint: it's a lot less than the 5V output of the adapter]
Title: Re: Remote Battery
Post by: SnowHiker on March 30, 2018, 03:42:20 PM
I don't.
That doesn't surprise me as I thought you had a cabled station.

Have you actually done that, and checked the results?  It doesn't work (at least on recent models).
How do you know it doesn't work?  Yes, I have tried it along with the flashing LED, TBH I don't know how fast it would have discharged otherwise, but it seems to be commonly thought on this forum that it does discharge the cap much faster, but we could be wrong.  And I do have an older model.


And what is the specified maximum voltage rating of the supercap?  [Hint: it's a lot less than the 5V output of the adapter]
I've checked my solar panel in bright sunlight and it was putting out around 2.5V. Are you saying that the higher voltage can't override the lower voltage?


N.B. - the #6625 AC-adapter INPUTS AC-voltage but OUTPUTS 5VDC voltage which over-rides the 3VDC from the CR123A battery...and...the Super Cap voltage.
Title: Re: Remote Battery
Post by: dalecoy on March 30, 2018, 04:00:31 PM
The station that I operate continuously is a cabled station, yes.  That doesn't mean I have no information about wireless stations.

Davis uses protective diodes in all power circuits.  The (recent, at least) ISS is no exception.

No, I am not saying "higher voltage can't override lower voltage" - but please define "override".

And I don't know what Old Tele man means by "overrides". 

Davis circuitry (based on diodes to prevent reverse-flow) allows the highest available voltage source to power the ISS.  That just makes sense.  They also protect the supercap from reasonable over-voltage conditions.

Having said that, yes, soldering wires to the battery holder will work - it's just more convenient to use the jack that Davis provided.  [And the on-board battery could be left in, to provide an additional power source]
Title: Re: Remote Battery
Post by: dalecoy on March 30, 2018, 04:03:52 PM
Yes, I have tried it along with the flashing LED, TBH I don't know how fast it would have discharged otherwise, but it seems to be commonly thought on this forum that it does discharge the cap much faster, but we could be wrong.  And I do have an older model.

Let's hear from someone who has (without using the "flashing LED" also) used the power adapter to try to discharge the supercap, and then actually measured the voltage on the supercap. 

Title: Re: Remote Battery
Post by: SnowHiker on March 30, 2018, 05:51:27 PM
The station that I operate continuously is a cabled station, yes.  That doesn't mean I have no information about wireless stations.

Davis uses protective diodes in all power circuits.  The (recent, at least) ISS is no exception.

No, I am not saying "higher voltage can't override lower voltage" - but please define "override".

And I don't know what Old Tele man means by "overrides". 

Davis circuitry (based on diodes to prevent reverse-flow) allows the highest available voltage source to power the ISS.  That just makes sense.  They also protect the supercap from reasonable over-voltage conditions.

Having said that, yes, soldering wires to the battery holder will work - it's just more convenient to use the jack that Davis provided.  [And the on-board battery could be left in, to provide an additional power source]
Given all that, I'm not sure what the purpose of your "hint" in your previous post was.  I think it's pretty clear that by "override" it was meant that the power from the adapter would be used instead of the power from the solar cell/supercap.  (Please don't ask me what "used" mean now.  :-) )

Does the circuit protection circuitry also protect the supercap from discharge when connected to a coil with a certain amount of internal impedance (such as an ac/dc adapter)?

As I mentioned before, yes he can leave the battery in the ISS, where it should last for years, whether or not the solar charging system still works with the adapter connected, assuming no frequent or prolonged power outages.  But the whole purpose of his endeavor was to remove the battery from the ISS in the first place where he could easily replace it when needed.  I've never had any experience with a lithium battery leaking or corroding, but I would still be wary about leaving it where I couldn't at least check it periodically.  But that may just be me.

It may be slightlly more convenient to use the jack, but simply connecting wires to the ISS from an external battery holder would be a one time thing, and he would most likely need to extend the adapter, which itself would involve splicing.  And before he uses the jack I would think he would want to know for sure that the ISS would keep transmitting in a power outage.

It sounds to me that the OP just wants to do what he asked about in the first place, but if he is interested in following the other suggestions, he would probably be well advised to do a little experimenting on his own while he has the station down and easily accessible.

As someone mentioned, a cabled station may have been better, assuming extra sensors, or the ability to move the console wasn't desired. So even if the battery is remoted, the wireless is still more flexible.  But, while looking at all possibilities is good, I'm not really seeing what the big problem is with the OP's original idea.
Title: Re: Remote Battery
Post by: Mattk on March 30, 2018, 06:10:17 PM
Well then I need to use a Battery Eliminator to do a remote battery pack LOL...all this talk of using the DC jack on the board doesn't do what I want - it would override the solar panel and the cap.

So what is it you exactly want? and why won't the DC jack do it.

As previously mentioned power the DC jack with a 6V or 12v/5v DC convertor from battery/charger and totally forget about the Supercap and solar panel. The CR123 battery can then be optional
Title: Re: Remote Battery
Post by: SnowHiker on March 30, 2018, 06:54:17 PM
A couple of other ideas not discussed yet:

-Put a huge street lamp in front of it that comes on at night to shine on the solar cell and keep the supercap charged even on the longest, darkest nights, so that a battery should never be needed.  Maybe add a generator if you're worried about a power outage that happens to last all night.

-Install it permanently on your vehicle and power it by your truck/car battery.

(This post may be two days early.)
Title: Re: Remote Battery
Post by: dalecoy on March 30, 2018, 08:11:53 PM
Does the circuit protection circuitry also protect the supercap from discharge when connected to a coil with a certain amount of internal impedance (such as an ac/dc adapter)?

Yes.  [I presume you're asking about the circuitry between the external power jack and the supercap, etc.]

[And also, assuming that the recently-manufactured adapters are constructed that way, would be incorrect]
Title: Re: Remote Battery
Post by: SnowHiker on March 30, 2018, 08:37:27 PM

Yes.  [I presume you're asking about the circuitry between the external power jack and the supercap, etc.]

[And also, assuming that the recently-manufactured adapters are constructed that way, would be incorrect]
How do you know all this, and how are recently-manufactured adapters different than the ones that have come before?
Title: Re: Remote Battery
Post by: SnowHiker on March 30, 2018, 08:49:10 PM
Also, can I assume that since Davis much improved the power circuitry and isolated the various components so effectively, that bad capacitor, particularly one that fails in the shorted mode, will no longer cause the battery to drain prematurely?
Title: Re: Remote Battery
Post by: dalecoy on March 30, 2018, 09:16:18 PM
Also, can I assume that since Davis much improved the power circuitry and isolated the various components so effectively, that bad capacitor, particularly one that fails in the shorted mode, will no longer cause the battery to drain prematurely?

You can't assume that - because a capacitor that fails doesn't "cause the battery to drain prematurely".  A failed capacitor doesn't store energy, and therefore the battery has to power the ISS.  That is, of course, the job of the battery - to power the ISS when there are no other available power sources.

(Rough explanation): If the capacitor fails "open circuit", the solar cell powers the ISS during the day, and the battery powers it at night, thus draining the battery.  If the capacitor fails "shorted", that effectively shorts out the solar cell, and therefore the battery powers the ISS full-time.  Thus draining the battery faster. 

The job of the battery is to power the ISS in the event that the other power sources fail. 
Title: Re: Remote Battery
Post by: dalecoy on March 30, 2018, 09:31:10 PM

Yes.  [I presume you're asking about the circuitry between the external power jack and the supercap, etc.]

[And also, assuming that the recently-manufactured adapters are constructed that way, would be incorrect]
How do you know all this, and how are recently-manufactured adapters different than the ones that have come before?

1.  Davis isn't dumb, and that sort of simple diode-isolation circuitry is taught in Electrical Engineering 101 class.
2.  I have examined a fair amount of Davis circuitry.

Early adapters were simple transformer circuits, which were inefficient, and (probably of most importance to Davis) costly to manufacture, primarily because of the large amount of copper required.

More recent power adapters use an active circuitry which is much more efficient, and costs a lot less.  It also generates electrical "noise" on the DC output, therefore requiring a ferrite isolator on the DC line (that big fat thing on the wire).

johnd could tell us approx. when that change was made - and maybe if the part number actually changed.
Title: Re: Remote Battery
Post by: SnowHiker on March 30, 2018, 10:10:37 PM

You can't assume that - because a capacitor that fails doesn't "cause the battery to drain prematurely".  A failed capacitor doesn't store energy, and therefore the battery has to power the ISS.  That is, of course, the job of the battery - to power the ISS when there are no other available power sources.

(Rough explanation): If the capacitor fails "open circuit", the solar cell powers the ISS during the day, and the battery powers it at night, thus draining the battery.  If the capacitor fails "shorted", that effectively shorts out the solar cell, and therefore the battery powers the ISS full-time.  Thus draining the battery faster. 

The job of the battery is to power the ISS in the event that the other power sources fail.
Nah, there are plenty of examples of batteries dying within weeks or less when a supercap fails, not the eight months or so that Davis claims. Read over these forums, you should find many examples, and I know from personal experience how quickly a battery can drain, even after fresh ones are put in when a cap fails. On one board which this happens I unsoldered the cap and the battery lasted for a good long time.  I also have a temp station without a cap and can verify that the battery lasts for many months.

So you really don't need to talk to me, or many others who have experienced supercap failures, how the battery is supposed to work.
Title: Re: Remote Battery
Post by: dalecoy on March 30, 2018, 10:33:23 PM
Nah, there are plenty of examples of batteries dying within weeks or less when a supercap fails, not the eight months or so that Davis claims. Read over these forums, you should find many examples, and I know from personal experience how quickly a battery can drain, even after fresh ones are put in when a cap fails. On one board which this happens I unsoldered the cap and the battery lasted for a good long time.  I also have a temp station without a cap and can verify that the battery lasts for many months.

So you really don't need to talk to me, or many others who have experienced supercap failures, how the battery is supposed to work.

Oh - you meant premature as in days or a few weeks.

Those rapid battery failures are primarily the result of a capacitor that failed, and leaked conductive electrolyte onto the circuit board.  That effectively bypasses the Davis circuitry and causes a lot of drain on the battery.

I'm guessing that when you unsoldered that capacitor, you also cleaned up the messy electrolyte. 

(And no, I really don't need to talk to you)
Title: Re: Remote Battery
Post by: SnowHiker on March 30, 2018, 10:43:13 PM

1.  Davis isn't dumb, and that sort of simple diode-isolation circuitry is taught in Electrical Engineering 101 class.
2.  I have examined a fair amount of Davis circuitry.

Early adapters were simple transformer circuits, which were inefficient, and (probably of most importance to Davis) costly to manufacture, primarily because of the large amount of copper required.

More recent power adapters use an active circuitry which is much more efficient, and costs a lot less.  It also generates electrical "noise" on the DC output, therefore requiring a ferrite isolator on the DC line (that big fat thing on the wire).

johnd could tell us approx. when that change was made - and maybe if the part number actually changed.
I'm glad we live in a perfect world where electronics theory and real world applications all work perfectly.

So can you verify for me that when the new (switching?) adapters are unplugged that the resistance between the pos and neg contacts of the connectors are infinite?

I'm also curious if the adapter jack on the wireless system was really meant to be an alternate power source, or is just there for testing, or just because they just put more or less the same components on the wireless and cabled boards.  For example, my extra temperature station for the VP1 wasn't even meant to be solar powered, it was an indoor station, yet it still had the very same board as the ISS including the supercap.

The point is, do you know exactly how the jack interfaces with the solar charging circuitry, or are you making assumptions yourself?
Title: Re: Remote Battery
Post by: dalecoy on March 30, 2018, 11:01:35 PM
So can you verify for me that when the new (switching?) adapters are unplugged that the resistance between the pos and neg contacts of the connectors are infinite?

No, it is not infinite.  That's not the way diode protection works.


I'm also curious if the adapter jack on the wireless system was really meant to be an alternate power source, or is just there for testing, or just because they just put more or less the same components on the wireless and cabled boards. 


Yes, No, Sorta.

Perhaps johnd will comment.
Title: Re: Remote Battery
Post by: SnowHiker on March 30, 2018, 11:48:41 PM
For example, my extra temperature station for the VP1 wasn't even meant to be solar powered, it was an indoor station, yet it still had the very same board as the ISS including the supercap.
BTW, you may consider just consider this anecdotal evidence, but when a cap died in my ISS, I removed it and swapped the board with the temp station as it didn't need a supercap.  The battery seems to last much longer in the temp station since I put the board in without a cap, even though the cap was good.  I can't give hard evidence as I use the temp station for a few months in winter, and I started putting in the used battery from the ISS when I swap it out for a new one every couple of years.  But even used the battery seems to have more than the eight month life Davis claims, and seems to last longer than a fresh battery did in the temp station with the good cap.  So that helps convince me that the components aren't perfectly isolated and have no effect on each other.
Title: Re: Remote Battery
Post by: johnd on March 31, 2018, 07:20:51 AM
Perhaps johnd will comment.

Sorry, don't really have anything useful to add - I suspect that only those in the original Davis design team know the answer. Maybe it's for testing (though that would maybe imply manual testing, which would be somewhat clunky).

Or perhaps it was totally minimal cost to add a belt and braces aspect with the extra 5v input or simply to provide more flexibility to the powering options. It's maybe not unrelated that the AC-powered repeater versions (7626/7653) have been discontinued as unnecessary given that the solar-powered version can be AC-powered anyway.

TBH I'm not sure there's much point in speculating - AFAIK no-one outside of Davis knows the precise circuit-level details of eg how the power options (solar/supercap/battery/5v) are designed or how they might have changed over time and so we're unlikely ever to find out whether any given theory is right or wrong.
Title: Re: Remote Battery
Post by: dalecoy on March 31, 2018, 10:30:44 AM
Thanks, johnd

You did mention the differences in adapters in this previous note: 
http://www.wxforum.net/index.php?topic=13958.msg136450#msg136450

And my statements are based on examination (and some tests) of a wireless circuit board (with a supercap problem) that I repaired for a friend.  As well as the fact that the diode protection (which you mentioned in that note) is standard engineering practice.

But, as you also noted - many things may have changed over time.

There might have been a version that viewed that jack as (also) a possible way to supply power to some external device, which would explain the (then) lack of diode protection, and the (then) ability to discharge the supercap using that jack.
Title: Re: Remote Battery
Post by: azchrisf on April 08, 2018, 10:59:17 AM
I'd be curious -

Can anyone who knows the internals throw up a quick schematic of how the power handling in an ISS works?
Title: Re: Remote Battery
Post by: dalecoy on April 08, 2018, 12:51:51 PM
I'd be curious -

Can anyone who knows the internals throw up a quick schematic of how the power handling in an ISS works?

That would be useful.  I have measured some of those characteristics (on only one sample), but not enough to draw a schematic.  "Hacking" a schematic would require destructive analysis of a circuit board.  And there might have been design changes over the years. 

For instance, I measured that the external power jack can provide power to operate the ISS, but the battery in the ISS does not provide power output through that external power jack.  But I didn't measure a lot of other things - for instance, I don't know if the external power jack can be used to charge the supercap.  Nor whether the solar panel can provide power output through that jack.  Etc. 

Disregarding the external power jack, we know that (depending on available voltage):
1.  The solar panel can power the ISS and charge the supercap.
2.  The supercap can power the ISS.
3.  The battery can power the ISS, but does not charge the supercap.

From there, several different schematics could be drawn.  I would be happy to see an official schematic, of course.
Title: Re: Remote Battery
Post by: adnadeau on October 20, 2018, 10:45:52 AM
I know this is an old post; I just ran across it.  Here's a couple of pictures of the SIM PCB, both to the same scale.  You can see that the power distribution is complicated.  Looking at the reversed PCB back picture, notice the 3 large through-holes in a triangle configuration.  The right one goes to the center contact of the power jack, the left one to the shell, & the bottom one is a N.C. to the shell (my assumption based on a datasheet of a similar jack).  The thick trace goes to the supercap neg through-hole.  On the top of the PCB, the center pin contact goes to a cylindrical surface mounted diode D12 & then to D11 & then ??  The solar panel pins go somewhere else.
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Title: Re: Remote Battery
Post by: dalecoy on October 20, 2018, 11:32:06 AM
Thanks for the additional information. 
Title: Re: Remote Battery
Post by: rdsman on October 20, 2018, 01:03:24 PM
Here is some food for thought about the power circuitry:

I have a Vue ISS.  About one year ago I got the dreaded "Low Battery" message.  I replaced the battery with a good one but was unable to clear the message on the console.  I took the new battery out and measured the voltage and it was now dead.  I connected my bench power supply to the ISS battery terminals and it maxed out the current limiter in the power supply.  So I measured the battery input of the ISS with an ohmmeter - it is .1 ohms forward and reverse.  It is not going to work that way.

The ISS at that time would still run on solar power and charge the supercap.  A month ago it stopped charging the supercap.  Now it will only run on solar power as long as the sun is shining.  Or it will run off of my bench power supply in place of the solar cell.

Time for something new!

Title: Re: Remote Battery
Post by: GW400 on February 06, 2019, 10:27:37 AM
Don't bother trying to solder to the terminals. The SIM board has a jack on it for the Davis size console plug. If you need a plug, you can get a Davis USB console cable from Scaled Instruments (#6627) for $6 plus shipping, and splice it.

As far a gauge, it uses such little current, just about anything would work. Get something black that will resist UV. 18 gauge zip cord would be OK.
Are you referring to the RJ connector at top right in picture?
Title: Re: Remote Battery
Post by: Bushman on February 06, 2019, 02:59:18 PM
The power input is the barrel connector above the RJ plug.
Title: Re: Remote Battery
Post by: GW400 on February 06, 2019, 03:10:03 PM
Well then I need to use a Battery Eliminator to do a remote battery pack LOL...all this talk of using the DC jack on the board doesn't do what I want - it would override the solar panel and the cap.

Not correct.  The jack has no "override the solar panel and the cap" function.  It just provides a convenient way to connect an additional voltage (power) source to the ISS.

What was it that you wanted to do?

Have you or anyone else actually tested and verified that providing external power through the jack works?
Title: Re: Remote Battery
Post by: dalecoy on February 06, 2019, 03:33:54 PM
Have you or anyone else actually tested and verified that providing external power through the jack works?

Yes
Title: Re: Remote Battery
Post by: GW400 on February 06, 2019, 03:53:40 PM
Good!
Kindly share some details
Title: Re: Remote Battery
Post by: Mattk on February 06, 2019, 03:54:48 PM
Well then I need to use a Battery Eliminator to do a remote battery pack LOL...all this talk of using the DC jack on the board doesn't do what I want - it would override the solar panel and the cap.

Not correct.  The jack has no "override the solar panel and the cap" function.  It just provides a convenient way to connect an additional voltage (power) source to the ISS.

What was it that you wanted to do?

Have you or anyone else actually tested and verified that providing external power through the jack works?

Definitely does as that is what the jack is for. You can also replace the CR123 with an insert adapter and run the battery backup from 2* D cells, ISS will basically never have a power failure again. As for the solar panel, I generally disconnect it and replace it with a blank door     
Title: Re: Remote Battery
Post by: johnd on February 06, 2019, 04:03:36 PM
Have you or anyone else actually tested and verified that providing external power through the jack works?



Of course - it's a standard way of powering a VP2 transmitter board from eg the Davis AC mains adapter. But if the board has somehow developed a short across its DC lines somewhere then it won't do the mains adapter much good. So, if possible, you might want to check the current draw.
Title: Re: Remote Battery
Post by: GW400 on February 06, 2019, 04:18:27 PM
Well then I need to use a Battery Eliminator to do a remote battery pack LOL...all this talk of using the DC jack on the board doesn't do what I want - it would override the solar panel and the cap.

Not correct.  The jack has no "override the solar panel and the cap" function.  It just provides a convenient way to connect an additional voltage (power) source to the ISS.
That could work.
Any suggestion where to find a water tight (IP65) and UV resistant 2*D battery holder?

What was it that you wanted to do?

Have you or anyone else actually tested and verified that providing external power through the jack works?

Definitely does as that is what the jack is for. You can also replace the CR123 with an insert adapter and run the battery backup from 2* D cells, ISS will basically never have a power failure again. As for the solar panel, I generally disconnect it and replace it with a blank door   
Title: Re: Remote Battery
Post by: GW400 on February 06, 2019, 05:05:37 PM
Any suggestion of a watertight (IP67) and UV resistant battery compartment that can be used for powering ISS with 2xD batteries?
Title: Re: Remote Battery
Post by: Bushman on February 06, 2019, 10:37:55 PM
I'm p[retty certain the standard Davis external power adapter is NOT 3v
Title: Re: Remote Battery
Post by: Mattk on February 07, 2019, 01:17:36 AM
I'm p[retty certain the standard Davis external power adapter is NOT 3v

Did somebody mention that it was, so not exactly sure of your query. But no, the external power for consoles, ISS or similar is typically 5 volts but can handle up to around 6.5 volts.
Title: Re: Remote Battery
Post by: johnd on February 07, 2019, 03:21:14 AM
But no, the external power for consoles, ISS or similar is typically 5 volts but can handle up to around 6.5 volts.

I think that 6.0v is the official max voltage, though it's safer to stick to the standard 5.0v max. (I have seen consoles with the voltage regulator burnt out by a voltage >6v).
Title: Re: Remote Battery
Post by: Mattk on February 07, 2019, 05:19:44 AM
But no, the external power for consoles, ISS or similar is typically 5 volts but can handle up to around 6.5 volts.

I think that 6.0v is the official max voltage, though it's safer to stick to the standard 5.0v max. (I have seen consoles with the voltage regulator burnt out by a voltage >6v).

One would have thought the max voltage would be the upper limit of the VP solar kit, 6V battery but does output up to around 6.8v
Title: Re: Remote Battery
Post by: johnd on February 07, 2019, 05:28:47 AM
One would have thought the max voltage would be the upper limit of the VP solar kit, 6V battery but does output up to around 6.8v

The official word from Davis is not to exceed 6v. Slightly higher voltages can certainly be tolerated but the higher the voltage and the longer the exposure then the life of the regulator will suffer. I can imagine that 6.5v (or maybe even 6.8v) is Ok for limited periods but you wouldn't want to be using eg continuous connection to a 7.5v mains adapter for more than brief periods.
Title: Re: Remote Battery
Post by: Mattk on February 07, 2019, 06:20:46 AM
One would have thought the max voltage would be the upper limit of the VP solar kit, 6V battery but does output up to around 6.8v

The official word from Davis is not to exceed 6v. Slightly higher voltages can certainly be tolerated but the higher the voltage and the longer the exposure then the life of the regulator will suffer. I can imagine that 6.5v (or maybe even 6.8v) is Ok for limited periods but you wouldn't want to be using eg continuous connection to a 7.5v mains adapter for more than brief periods.

Well nobody mentioned 7.5v mains adapter but if a Davis console or ISS can not handle a continuous power feed from a Davis solar kit then somebody has got it wrong, so that users don't get confused here we can say with confidence 6.8v is ok, it simply has to be because that is what the Davis solar kit puts out. 
Title: Re: Remote Battery
Post by: Bushman on February 07, 2019, 08:47:28 AM
I'm p[retty certain the standard Davis external power adapter is NOT 3v

Did somebody mention that it was, so not exactly sure of your query. But no, the external power for consoles, ISS or similar is typically 5 volts but can handle up to around 6.5 volts.

@GW400 was asking about powering it with 3v from two D batteries.
Title: Re: Remote Battery
Post by: pfletch101 on February 07, 2019, 11:19:57 AM
One would have thought the max voltage would be the upper limit of the VP solar kit, 6V battery but does output up to around 6.8v

The official word from Davis is not to exceed 6v. Slightly higher voltages can certainly be tolerated but the higher the voltage and the longer the exposure then the life of the regulator will suffer. I can imagine that 6.5v (or maybe even 6.8v) is Ok for limited periods but you wouldn't want to be using eg continuous connection to a 7.5v mains adapter for more than brief periods.

Well nobody mentioned 7.5v mains adapter but if a Davis console or ISS can not handle a continuous power feed from a Davis solar kit then somebody has got it wrong, so that users don't get confused here we can say with confidence 6.8v is ok, it simply has to be because that is what the Davis solar kit puts out.

I wasn't able to find the specs on the solar kit that (apparently) quote the 6.8V output voltage. However, being that it relies on solar power, this is much more likely to be an absolute maximum figure under ideal conditions than a continuous rating. There is a substantial difference, particularly in terms of potential thermal stress on the regulator circuitry, between occasionally being able to handle a peak power supply voltage of 6.8V and being able to handle a continuous input voltage of that level.
Title: Re: Remote Battery
Post by: Mattk on February 07, 2019, 03:17:22 PM
I'm p[retty certain the standard Davis external power adapter is NOT 3v

Did somebody mention that it was, so not exactly sure of your query. But no, the external power for consoles, ISS or similar is typically 5 volts but can handle up to around 6.5 volts.

@GW400 was asking about powering it with 3v from two D batteries.

I suggested you can replace the CR123 backup battery with 2*D cells (using an insert adapter in the CR123 battery holder) as well as powering it externally and then throw away the solar panels 
Title: Re: Remote Battery
Post by: Bushman on February 07, 2019, 03:40:59 PM
If you have external power, why bother changing out the nice compact 123 with yet another bulky thing?  A CR123 will last 6 months on its own if the unit is functioning properly.
Title: Re: Remote Battery
Post by: Mattk on February 07, 2019, 03:55:49 PM
One would have thought the max voltage would be the upper limit of the VP solar kit, 6V battery but does output up to around 6.8v

The official word from Davis is not to exceed 6v. Slightly higher voltages can certainly be tolerated but the higher the voltage and the longer the exposure then the life of the regulator will suffer. I can imagine that 6.5v (or maybe even 6.8v) is Ok for limited periods but you wouldn't want to be using eg continuous connection to a 7.5v mains adapter for more than brief periods.

Well nobody mentioned 7.5v mains adapter but if a Davis console or ISS can not handle a continuous power feed from a Davis solar kit then somebody has got it wrong, so that users don't get confused here we can say with confidence 6.8v is ok, it simply has to be because that is what the Davis solar kit puts out.

I wasn't able to find the specs on the solar kit that (apparently) quote the 6.8V output voltage. However, being that it relies on solar power, this is much more likely to be an absolute maximum figure under ideal conditions than a continuous rating. There is a substantial difference, particularly in terms of potential thermal stress on the regulator circuitry, between occasionally being able to handle a peak power supply voltage of 6.8V and being able to handle a continuous input voltage of that level.

And it is designed to handle that max all of the time, actually it will handle 7v continuous as the input voltage is clamped at 7v then dropped back via a protection diode, so yes a continuous 6.8v is by design. All this is tied up with the minimum voltage requirements which can be as low as 3 volts, WLIP requires at least 3.3v after the voltage regulators 
Title: Re: Remote Battery
Post by: Mattk on February 07, 2019, 04:00:10 PM
If you have external power, why bother changing out the nice compact 123 with yet another bulky thing?  A CR123 will last 6 months on its own if the unit is functioning properly.

In remote installations one can't have enough backup capacity regardless of the primary power source. In some instances largest capacity is typically dedicated to the backup. Have learnt not to rely on CR123's, AA's etc a long time ago.
Title: Re: Remote Battery
Post by: Bushman on February 07, 2019, 05:25:08 PM
Then plug the wall wart into a UPS>  That is what I did for years. Never a single drop (although longest power outage was only  a bit less thana day)
Title: Re: Remote Battery
Post by: Mattk on February 07, 2019, 06:06:05 PM
Then plug the wall wart into a UPS>  That is what I did for years. Never a single drop (although longest power outage was only  a bit less thana day)

I'm talking about stations that are totally solar, no mains power what so ever, they may have to run for 12 months totally unattended, talking about backing up Envoys from 80-100Ah batteries via multiple LVD's and adjustable regulators to progressively shutdown (and automatically turn on with power increases) unnecessary systems to at least maintain observations and logging. The likes of CR123's etc simply are not an option, I expect a system that might fail the day after a visit has the capability to still run and log data for at least 12 months even if the comms are down.   
Title: Re: Remote Battery
Post by: Bushman on February 07, 2019, 06:37:23 PM
If we are changing the subject...  what I'd do for a really remote setup (I am familiar with these BTW) is have a battery bank powered by a solar panel(s)
Title: Re: Remote Battery
Post by: Mattk on February 07, 2019, 07:21:41 PM
If we are changing the subject...  what I'd do for a really remote setup (I am familiar with these BTW) is have a battery bank powered by a solar panel(s)

Well I wasn't changing the subject but exactly and 12 volt solar systems are more common than 6 volt and there are some very good fixed and adjustable regulators out there. A complete top down remote system running multiple ISS's, multiple anemometers, multiple loggers and routers is a combination of independent dual solar systems, dual/split regulators, multiple batteries and LVD's right down to ISS backup using 2*D cells instead of a CR123 even with the capability to run 2 lots of 2*D cells in parallel. 
Title: Re: Remote Battery
Post by: Old Tele man on February 07, 2019, 07:57:24 PM
FWIW a small, high-efficiency, switching down-converter CHIP can get you 6VDC from 12VDC with minimum loss.
Title: Re: Remote Battery
Post by: GW400 on February 08, 2019, 01:32:15 AM
FWIW a small, high-efficiency, switching down-converter CHIP can get you 6VDC from 12VDC with minimum loss.
This is interesting!
What is the spec and make for the converter chip?
Title: Re: Remote Battery
Post by: Old Tele man on February 08, 2019, 04:25:46 PM
FWIW a small, high-efficiency, switching down-converter CHIP can get you 6VDC from 12VDC with minimum loss.
This is interesting!
What is the spec and make for the converter chip?

This is one (of many) such units available (mostly from China): https://www.ebay.com/p/12v-to-6v-DC-Buck-Converter-Step-Down-Module-Power-Supply-Voltage-Regulator-YM/1253103178 (https://www.ebay.com/p/12v-to-6v-DC-Buck-Converter-Step-Down-Module-Power-Supply-Voltage-Regulator-YM/1253103178)

This is a 5VDC output range of devices: https://www.mouser.com/ds/2/75/EC5SBW-V10-557892.pdf (https://www.mouser.com/ds/2/75/EC5SBW-V10-557892.pdf)

This is MOUSER's listing of devices (some cheap, some $$$$):  https://www.mouser.com/Search/Refine?Keyword=12VDC+to+6VDC+buck+converter (https://www.mouser.com/Search/Refine?Keyword=12VDC+to+6VDC+buck+converter)
Title: Re: Remote Battery
Post by: GW400 on February 12, 2019, 01:59:21 PM
FWIW a small, high-efficiency, switching down-converter CHIP can get you 6VDC from 12VDC with minimum loss.
This is interesting!
What is the spec and make for the converter chip?

This is one (of many) such units available (mostly from China): https://www.ebay.com/p/12v-to-6v-DC-Buck-Converter-Step-Down-Module-Power-Supply-Voltage-Regulator-YM/1253103178 (https://www.ebay.com/p/12v-to-6v-DC-Buck-Converter-Step-Down-Module-Power-Supply-Voltage-Regulator-YM/1253103178)

This is a 5VDC output range of devices: https://www.mouser.com/ds/2/75/EC5SBW-V10-557892.pdf (https://www.mouser.com/ds/2/75/EC5SBW-V10-557892.pdf)

This is MOUSER's listing of devices (some cheap, some $$$$):  https://www.mouser.com/Search/Refine?Keyword=12VDC+to+6VDC+buck+converter (https://www.mouser.com/Search/Refine?Keyword=12VDC+to+6VDC+buck+converter)
Ended up ordering 12v-tp-6v-DC converter through eBay.
Thank you for the links!!
Title: Re: Remote Battery
Post by: GW400 on February 17, 2019, 04:54:26 AM
I noticed that solar panel hase two connectors to cable connected to ISS.
What about connecting external 5V-6V DC to these connectors.
Maybe a stupid question, but will that work?
Title: Re: Remote Battery
Post by: Mattk on February 17, 2019, 06:02:59 AM
I noticed that solar panel hase two connectors to cable connected to ISS.
What about connecting external 5V-6V DC to these connectors.
Maybe a stupid question, but will that work?

No No No
Title: Re: Remote Battery
Post by: GW400 on February 17, 2019, 07:35:03 AM
I noticed that solar panel hase two connectors to cable connected to ISS.
What about connecting external 5V-6V DC to these connectors.
Maybe a stupid question, but will that work?

No No No
You seems to be pretty sure that this is a bad idea.
Since you don't provide any background or details behind your opinion, we have no idea why.



Sent from my iPhone using Tapatalk
Title: Re: Remote Battery
Post by: Mattk on February 17, 2019, 04:01:21 PM
I noticed that solar panel hase two connectors to cable connected to ISS.
What about connecting external 5V-6V DC to these connectors.
Maybe a stupid question, but will that work?

No No No

You seems to be pretty sure that this is a bad idea.
Since you don't provide any background or details behind your opinion, we have no idea why.


Sent from my iPhone using Tapatalk

Sometimes it helps if users were to read the manual and specifications of the equipment they are using then they might understand why! The ISS solar panel provides less than 3 volts at 0.5 watts and only chargers the supercap which is backed up by the 3v replaceable battery. The external DC jack is provided for connecting 5-6v external power NOT the solar panel connector running <3 volts.
Title: Re: Remote Battery
Post by: dalecoy on February 17, 2019, 06:02:20 PM
I noticed that solar panel hase two connectors to cable connected to ISS.
What about connecting external 5V-6V DC to these connectors.
Maybe a stupid question, but will that work?

No No No
You seems to be pretty sure that this is a bad idea.
Since you don't provide any background or details behind your opinion, we have no idea why.


Please provide background or details about YOUR knowledge of electrical engineering.  I'll try to explain, at that level.
Title: Re: Remote Battery
Post by: GW400 on February 18, 2019, 04:40:05 PM
I noticed that solar panel hase two connectors to cable connected to ISS.
What about connecting external 5V-6V DC to these connectors.
Maybe a stupid question, but will that work?

No No No
You seems to be pretty sure that this is a bad idea.
Since you don't provide any background or details behind your opinion, we have no idea why.


Please provide background or details about YOUR knowledge of electrical engineering.  I'll try to explain, at that level.
Basic knowledge of electrical engineering
Title: Re: Remote Battery
Post by: dalecoy on February 18, 2019, 05:37:28 PM
OK, now please clarify for me:

I noticed that solar panel hase two connectors to cable connected to ISS.
What about connecting external 5V-6V DC to these connectors.

You asked about two connectors.  Are those connectors on the solar panel that you are looking at?  Or are they on wires coming from the solar panel?  Or are they on the ISS? or?????
Title: Re: Remote Battery
Post by: GW400 on February 19, 2019, 03:57:50 AM
OK, now please clarify for me:

I noticed that solar panel hase two connectors to cable connected to ISS.
What about connecting external 5V-6V DC to these connectors.

You asked about two connectors.  Are those connectors on the solar panel that you are looking at?  Or are they on wires coming from the solar panel?  Or are they on the ISS? or?????
The connector are on the solar panel, same connectors as where wires to ISS is connected.
Title: Re: Remote Battery
Post by: dalecoy on February 19, 2019, 10:12:20 AM
OK, now please clarify for me:

I noticed that solar panel hase two connectors to cable connected to ISS.
What about connecting external 5V-6V DC to these connectors.

You asked about two connectors.  Are those connectors on the solar panel that you are looking at?  Or are they on wires coming from the solar panel?  Or are they on the ISS? or?????
The connector are on the solar panel, same connectors as where wires to ISS is connected.

Then you were asking about the equivalent of connecting a 5-volt battery directly to a 3-volt battery.

Example: Your car has a 12-volt battery.  How about hooking up a 24-volt battery charger directly to it? 

Is that a satisfactory explanation of why Mattk said "No"?
Title: Re: Remote Battery
Post by: GW400 on February 23, 2019, 04:54:05 AM
OK, now please clarify for me:

I noticed that solar panel hase two connectors to cable connected to ISS.
What about connecting external 5V-6V DC to these connectors.

You asked about two connectors.  Are those connectors on the solar panel that you are looking at?  Or are they on wires coming from the solar panel?  Or are they on the ISS? or?????
The connector are on the solar panel, same connectors as where wires to ISS is connected.

Then you were asking about the equivalent of connecting a 5-volt battery directly to a 3-volt battery.

Example: Your car has a 12-volt battery.  How about hooking up a 24-volt battery charger directly to it? 

Is that a satisfactory explanation of why Mattk said "No"?

I did not know that solar panel was connected directly to the lithium battery on ISS, that was new to me.
My understanding has always been that solar panel charged the supercap, but I might be wrong.
Title: Re: Remote Battery
Post by: Mattk on February 23, 2019, 05:40:54 AM
OK, now please clarify for me:

I noticed that solar panel hase two connectors to cable connected to ISS.
What about connecting external 5V-6V DC to these connectors.

You asked about two connectors.  Are those connectors on the solar panel that you are looking at?  Or are they on wires coming from the solar panel?  Or are they on the ISS? or?????
The connector are on the solar panel, same connectors as where wires to ISS is connected.

Then you were asking about the equivalent of connecting a 5-volt battery directly to a 3-volt battery.

Example: Your car has a 12-volt battery.  How about hooking up a 24-volt battery charger directly to it? 

Is that a satisfactory explanation of why Mattk said "No"?

I did not know that solar panel was connected directly to the lithium battery on ISS, that was new to me.
My understanding has always been that solar panel charged the supercap, but I might be wrong.

Correct it is not connected directly to the lithium battery on ISS but the comment you refer didn't mention lithium battery just "directly to a 3-volt battery" and that basically is what the Supercap is, essentially a battery just under 3 volts.

And if your understanding has always been that solar panel charged the supercap then some of your comments don't indicate that at all otherwise there would have been no need for your query and comment? 
Title: Re: Remote Battery
Post by: dalecoy on February 23, 2019, 11:43:37 AM
Previously:

You seems to be pretty sure that this is a bad idea.
Since you don't provide any background or details behind your opinion, we have no idea why.

GW400, you didn't provide any background or details about your assumptions, regarding the circuitry involved.  Trying to "justify" a statement under those conditions isn't possible.

The simple explanation is: The power supply arrangement for the ISS is a rather complex circuitry that allows the "best" one of four power sources, at any instant, to run the ISS.  And "best" does not mean "highest voltage" (use the battery only as a last resort).

Those four power sources are: (1) External power jack; (2) Battery; (3) Solar Panel; (4) Supercap.

Hooking two of those together would defeat the engineering of the circuitry (and possibly damage some component). 
Title: Re: Remote Battery
Post by: GW400 on February 23, 2019, 01:28:03 PM
Previously:

You seems to be pretty sure that this is a bad idea.
Since you don't provide any background or details behind your opinion, we have no idea why.

GW400, you didn't provide any background or details about your assumptions, regarding the circuitry involved.  Trying to "justify" a statement under those conditions isn't possible.

The simple explanation is: The power supply arrangement for the ISS is a rather complex circuitry that allows the "best" one of four power sources, at any instant, to run the ISS.  And "best" does not mean "highest voltage" (use the battery only as a last resort).

Those four power sources are: (1) External power jack; (2) Battery; (3) Solar Panel; (4) Supercap.

Hooking two of those together would defeat the engineering of the circuitry (and possibly damage some component).

This explanation is more than good enough for me and it also provided additional information I have not seen elsewhere.
Thank you!

Then let's leave the topic of external power to solar panel connectors and move on to my next question (which should be an easy one):
Can anyone confirm the size and polarity of the power plug to be used?
By searching around I have found this information: 1.3mm DC plug, centre pin +.
I this correct?

My Davis Vantage Pro2 is half a days travel away and I can't easily measure it myself.
Title: Re: Remote Battery
Post by: Mattk on February 23, 2019, 02:29:41 PM
1.3mm, centre pin+ would be about right. Also if being used in the ISS then the jack is best to be a 90 degree or if straight then very short with no cable restraint, mostly just use the jack, throw away the screw on plastic cover and heat shrink
Title: Re: Remote Battery
Post by: GW400 on February 23, 2019, 02:33:00 PM
Thank you! [tup]
Title: Re: Remote Battery
Post by: GW400 on February 16, 2021, 07:34:27 AM
Previously:

You seems to be pretty sure that this is a bad idea.
Since you don't provide any background or details behind your opinion, we have no idea why.

GW400, you didn't provide any background or details about your assumptions, regarding the circuitry involved.  Trying to "justify" a statement under those conditions isn't possible.

The simple explanation is: The power supply arrangement for the ISS is a rather complex circuitry that allows the "best" one of four power sources, at any instant, to run the ISS.  And "best" does not mean "highest voltage" (use the battery only as a last resort).

Those four power sources are: (1) External power jack; (2) Battery; (3) Solar Panel; (4) Supercap.

Hooking two of those together would defeat the engineering of the circuitry (and possibly damage some component).
What is Davis' recommended voltage when providing power through external power jack, 5V DC or 6V DC?
Title: Re: Remote Battery
Post by: dalecoy on February 19, 2021, 04:29:27 PM

What is Davis' recommended voltage when providing power through external power jack, 5V DC or 6V DC?

I don't know.  But I do know that they say the Power Adapter for Vantage Family Consoles (#6625) works in that role.

Get one and measure it.
Title: Re: Remote Battery
Post by: Mattk on February 19, 2021, 07:30:24 PM
.... What is Davis' recommended voltage when providing power through external power jack, 5V DC or 6V DC?

External 5V is fine with ISS and Consoles as most Davis have a bottom threshold around 4.3'ish volts when using the WLIP, nominal 6 volts is no issue and has no problem with solar power output of up to 6.8 volts, 7 volts is getting a tad high but there is a restriction in the circuitry to clamp at 6.8 volts
Title: Re: Remote Battery
Post by: johnd on February 20, 2021, 03:36:00 AM
For the console, 6v is the highest voltage that's advised by Davis. Any higher will shorten the circuitry life. A little extra will probably take quite a while to cause damage. But I know that a 7.5v DC adapter that was rather stupidly substituted for the official Davis adapter by a particular reseller caused damage in a relatively short time.

ISS I've not seen any official Davis recommendations for, but I'm guessing not to exceed 5v. (But 5v adapters are two a penny these days, so that shouldn't be much hardship. That said, IIRC you do need one with the right-angle plug to connect easily into the SIM board.)

Battery powering via the DC jack input is a bit more tricky. I think I'd be wary of using say 2 x 18650 or LiPo cells in series, but say 4 x D cells might well be OK. I'm not sure whether it's feasible to inject say 3.7v from a single 18650 via the DC jack - there may be a voltage regulator that's expecting 5v as a minimum, but I don't know fir sure.
Title: Re: Remote Battery
Post by: Mattk on February 20, 2021, 04:30:47 AM
For the console, 6v is the highest voltage that's advised by Davis. Any higher will shorten the circuitry life.....

Maybe you meant to say nominal 6v? Something like the Solar Power Kit (#6610) and being a Davis product is something specifically recommended to power VP consoles so it doesn't make any sense to actually make a Solar kit that can output 6.8 volts then only advise a highest voltage of 6 volts? There can be a little confusion with such a claim?

And specifically there is a 7 volt upper voltage clamp as well as a protection diode which drops the voltage by 0.7 volts for this specific reason. Also the reason why operational voltage is typically a minimum of 4+ volts as the WLIP requires a voltage of at least 3.3V

And again the ISS is also made to run from something like a #6610 @ 6.8 volts so no problem here either.

     
Title: Re: Remote Battery
Post by: johnd on February 20, 2021, 04:55:29 AM
Simply quoting the official Davis response when this question was posed re the console PSU many moons ago. And yes I think it's understood that it's a nominal 6v, ie that say 6.2v won't do any damage. But applying say 7.5v definitely does cause problems. AIUI the voltage regulator doesn't like to dissipate that much extra heat long-term - it's OK for some weeks or even months, but gives up in the end.
Title: Re: Remote Battery
Post by: Mattk on February 20, 2021, 06:02:20 AM
Just stating the facts  :grin:

And of course 6.2v won't do any damage, Davis's own gear puts out 6.8 volts.

Not real sure why 7.5v was even raised relative to the question?

Title: Re: Remote Battery
Post by: azchrisf on February 25, 2021, 02:03:45 PM
1.3mm, centre pin+ would be about right. Also if being used in the ISS then the jack is best to be a 90 degree or if straight then very short with no cable restraint, mostly just use the jack, throw away the screw on plastic cover and heat shrink

Actually it's  a 3.5x1.3mm plug. I just got done doing an AC conversion.
https://www.amazon.com/gp/product/B081TYG48P/ref=ppx_yo_dt_b_asin_title_o07_s00?ie=UTF8&psc=1
Title: Re: Remote Battery
Post by: GW400 on March 15, 2021, 08:33:46 AM
Davis have a support article published regarding external battery:
https://support.davisinstruments.com/article/wll7jix28j-can-i-power-my-weather-station-iss-with-an-ac-power-source-faq
http://


"You would unplug the solar and remove the battery. Then plug the power adapter into port 2 below"

Has anyone tested if it is also works to have all three (external battery, solar power and internal battery) connected?
Title: Re: Remote Battery
Post by: azchrisf on March 15, 2021, 11:04:30 AM
Davis have a support article published regarding external battery:
https://support.davisinstruments.com/article/wll7jix28j-can-i-power-my-weather-station-iss-with-an-ac-power-source-faq
http://


"You would unplug the solar and remove the battery. Then plug the power adapter into port 2 below"

Has anyone tested if it is also works to have all three (external battery, solar power and internal battery) connected?

I have AC, battery and supercap connected and no issues. However, Supercap does not seem to charge without the solar panel. The CR123A I think would make sense to keep, because if the mains power goes out you still got something that can transmit if your circuit to the station fails, or everything fails and you have your console on battery backup or something.
Title: Re: Remote Battery
Post by: GW400 on March 15, 2021, 11:24:16 AM
Davis have a support article published regarding external battery:
https://support.davisinstruments.com/article/wll7jix28j-can-i-power-my-weather-station-iss-with-an-ac-power-source-faq
http://


"You would unplug the solar and remove the battery. Then plug the power adapter into port 2 below"

Has anyone tested if it is also works to have all three (external battery, solar power and internal battery) connected?

I have AC, battery and supercap connected and no issues. However, Supercap does not seem to charge without the solar panel. The CR123A I think would make sense to keep, because if the mains power goes out you still got something that can transmit if your circuit to the station fails, or everything fails and you have your console on battery backup or something.
Thank you!
That was good to hear. I was also worried about having only one power source in case of outage on the grid.
May I ask what voltage are you delivering to power jack on PCB?
Title: Re: Remote Battery
Post by: azchrisf on March 15, 2021, 11:31:02 AM
5.5 volts DC
The jack is spec'd for 3.3-6V IIRC, same as the Davis power brick for the console.
Tip is positive on the jack.