Topic: Remote Battery

[azchrisf]

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?

[SLOweather]

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.

[vreihen]

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

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?????

[johnd]

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.

[azchrisf]

Thanks guys - SLO, you had a great idea with the AC plug in the units instead of soldering.

[johnd]

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.

[johnd]

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.

[EA1EF]

A 18650 lithium battery should work fine...

[johnd]

A 18650 lithium battery should work fine...

Yes, certainly. But why bother if it's feasible to use an AC mains adapter?

[EA1EF]

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

[azchrisf]

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.

[dalecoy]

1 because the power consuption are a lot

Compared to the total environmental cost of batteries?

[SLOweather]

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.

[azchrisf]

SLO,

Great idea. What about some 18650 cells?

[SnowHiker]

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.

[SnowHiker]

 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?

[SnowHiker]

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. 

[Mattk]

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

....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.

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

Works perfectly

....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. 

[SnowHiker]

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.

[EA1EF]

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

[azchrisf]

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.

[dalecoy]

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.

[azchrisf]

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.

[dalecoy]

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?

[SnowHiker]

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?