Author Topic: Losing connection at night  (Read 4475 times)

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Offline ocala

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Losing connection at night
« on: October 16, 2011, 03:16:53 PM »
Just wanted some opinions.
VP2 wireless unit is  6 years old now. Last 2 nights ISS stops transmitting about 7PM and starts transmitting again about 9-10AM next day. Checked the battery and it is fine. Flipped dip switch 4 and I am getting a blink during times when it's not transmitting. Did noticed that a bird or something with sharp claws really scratched the solar panel and there are 2 pencil tip size holes in the plastic cover on the solar panel. Don't know if this has anything to do with the problem.
Also I have had an on going problem with the ISS saying the battery is low when in fact it's fine. A discussion with Davis about this a couple years ago yielded a live with it response from Davis since it was out of warranty.
Debating whether to change the ISS board and the solar cover.
Just curious what you guys think.

Offline north of 60

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Re: Losing connection at night
« Reply #1 on: October 16, 2011, 03:46:59 PM »
You have old ISS board which the supercap wasn't glue or tied down,  just leads soldered in.  Just get a new  2.7v 10F supercap for couple dollars,  solder it in and it will work like new.  also your battery is dead,  if the battery was good the station would work all night even if supercap was depleted which is what the backup battery was designed to do,  your bad supercap is draining battery fast. 

Offline wxtech

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Re: Losing connection at night
« Reply #2 on: October 16, 2011, 03:57:23 PM »
Do some simple cheap things first.  
Check the solar connection to the SIM board.  If you have a multimeter, check the solar voltage during full sun.  It should be approximately 2 volts.
Remove the white plastic cover on the SIM board (4 screws).  Is the super capacitor corroded?  Check the voltage on the capacitor.  It should be approximately 2.6 volts.
Is your battery installed correctly.  The + goes to the left.  
Post a picture of the SIM board.
The battery should power the ISS for 8 months with no solar.  The solar panel and supercapacitor should power the ISS during day full sun and overnight even if there is no battery installed.
So either the battery is dead or not connected; the solar panel isn't fully charging the supercapacitor; or the supercapacitor has failed.
Edit:  I agree with North of 60.  I was measuring while he posted.
« Last Edit: October 16, 2011, 03:59:58 PM by wxtech »
Al Washington, Lexington, Ga.,  NWS Coop station=LXTG1, Fischer Porter, SRG, MMTS. 
CoCoRaHS=GA-OG-1. CWOP=CW2074.  Davis VP2+ WLIP 5.9.2, VP(original) serial, VWS v15.00 p02. ImageSalsa, Win7 & Win8 all-in-one.

Offline dalecoy

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Re: Losing connection at night
« Reply #3 on: October 16, 2011, 04:05:53 PM »
Checked the battery and it is fine.

Exactly how did you check the battery?  (I'm not being picky here - how you checked it has some bearing on what the problem might be).

Offline ocala

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Re: Losing connection at night
« Reply #4 on: October 17, 2011, 12:53:44 PM »
Sorry to get back so late.
Battery voltage was checked with a meter. 3.18.
Checked the voltage of the solar panel and it was 1.99.
Didn't have time last night to pull off the cover to view the cap but will try today.
Now the strange part. It worked fine last night. Had data all night. Sounds like it may be a cap issue but won't know until I get in there.
At least for now it's working.
Will update about the cap.

Offline dalecoy

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Re: Losing connection at night
« Reply #5 on: October 17, 2011, 01:54:32 PM »
Checked the battery and it is fine.

Exactly how did you check the battery?  (I'm not being picky here - how you checked it has some bearing on what the problem might be).


Battery voltage was checked with a meter. 3.18.


Yes, OK, so did you pull the battery out to check the voltage?  Or just check the voltage across the battery contacts with the battery in the holder (and, in that case, did you measure the voltage across the battery contacts or the holder contacts or somewhere else)?  Was the transmitter operating when you checked the battery?  Operating in test mode or regular mode?  Etc.

That may or may not be important, of course, but (for instance) if you removed the battery to check the voltage, that's significant. 

Offline ocala

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Re: Losing connection at night
« Reply #6 on: October 17, 2011, 02:51:40 PM »
Checked the battery and it is fine.

Exactly how did you check the battery?  (I'm not being picky here - how you checked it has some bearing on what the problem might be).


Battery voltage was checked with a meter. 3.18.


Yes, OK, so did you pull the battery out to check the voltage?  Or just check the voltage across the battery contacts with the battery in the holder (and, in that case, did you measure the voltage across the battery contacts or the holder contacts or somewhere else)?  Was the transmitter operating when you checked the battery?  Operating in test mode or regular mode?  Etc.

That may or may not be important, of course, but (for instance) if you removed the battery to check the voltage, that's significant. 
I pulled the battery out to check it.
You know I never did think about checking the battery while in the holder. That's something I'll have to try. If something is loose there that may account for the intermittent readings.
Thanks for the suggestion.

Offline dalecoy

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Re: Losing connection at night
« Reply #7 on: October 17, 2011, 03:08:04 PM »
OK, let's see.

This is a 6-year-old apparatus exposed to the elements.  It quits working at night.  Hmmm.  Perhaps bad supercap and bad battery.

Pull the battery out, check it.  It's OK.  Put the battery back in, and the thing works.

My first suspicion (about the battery) would be some dirt or corrosion on the battery holder contacts, that was preventing the battery from supplying voltage.  AND probably a bad supercap.




Offline Flag

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Re: Losing connection at night
« Reply #8 on: October 18, 2011, 03:23:15 AM »
When all else fails simply external power the ISS, problem fixed, period.

Offline dalecoy

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Re: Losing connection at night
« Reply #9 on: October 18, 2011, 10:03:25 AM »
When all else fails simply external power the ISS, problem fixed, period.

That's one solution - replacing solar/supercap/battery with a single source.  But it's not perfect either.

Commercial power will fail - of course you can use a UPS.

...which may run out of its battery capacity - of course you can have a backup generator....

etc.

Offline ocala

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Re: Losing connection at night
« Reply #10 on: October 18, 2011, 12:27:09 PM »
Finally got around to pulling off the cover today and the cap is corroded.
Still doesn't explain why it stopped at night but it may be as dalecoy said that some how the battery just lost connection with the contacts.  FWIW I also checked the contact connections and it's the same voltage as the battery which is down to 3.09 from 3.18. I assume because the cap is shot.

Now since I don't have much electrical know how can someone tell me what it is I have to order and also a website where I can order it. Or does Radio Shack carry this sort of thing.
Thanks.

Offline wxtech

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Re: Losing connection at night
« Reply #11 on: October 18, 2011, 12:37:56 PM »
Not Radio Shack, Mouser or Digi-Key.  How much electronics soldering experience do you have?  This cap needs special lead handling or the replacement will fail also.
Take the SIM board out, put it in a small priority box and mail it to me.  I have some slightly used super caps.  I can install it and mail it back.
Al
Al Washington, Lexington, Ga.,  NWS Coop station=LXTG1, Fischer Porter, SRG, MMTS. 
CoCoRaHS=GA-OG-1. CWOP=CW2074.  Davis VP2+ WLIP 5.9.2, VP(original) serial, VWS v15.00 p02. ImageSalsa, Win7 & Win8 all-in-one.

Offline ocala

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Re: Losing connection at night
« Reply #12 on: October 18, 2011, 01:00:15 PM »
Have no soldering experience at all Al.
PM me your address and I mail it to you today.

Offline Flag

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Re: Losing connection at night
« Reply #13 on: October 19, 2011, 05:10:43 AM »
When all else fails simply external power the ISS, problem fixed, period.

That's one solution - replacing solar/supercap/battery with a single source.  But it's not perfect either.

Commercial power will fail - of course you can use a UPS.

...which may run out of its battery capacity - of course you can have a backup generator....

etc.

Let me explain further, when I mention "external power" power adapters are out but SLA battery and charger is ideal. Even without the charger a reasonable size battery will run an ISS for ages before even going to backup.


Supercap charged by solar is a thing I simply don't use.

Offline wxtech

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Re: Losing connection at night
« Reply #14 on: October 20, 2011, 11:18:56 PM »
Update on this repair project:
He mailed the board to me.  I replaced the corroded supercap.  It was definately bad.  
Testing the board after replacing the supercap, I noticed that it transmitted only a few times then quit.  The transmit code was set to channel 8.  I now have it on channel 1.  It may be a battery holder connection problem.  It has been transmitting for an hour now with the battery only half in the battery holder.  The battery holder has no corrosion and the terminals seem to make good contact.  A bump or vibration sometimes causes it to stop/start transmitting.  The CR123 battery is new with 3.18 volts installed and under operating load.
I suspect that some component on the board is intermittent or there is a break in a soldered connection.
His SIM board is now providing data to my WU site:
http://www.wunderground.com/weatherstation/WXDailyHistory.asp?ID=KGALEXIN1
and to my CWOP site:
http://www.findu.com/cgi-bin/wxpage.cgi?last=24&call=CW2074
Follow the operation of this SIM board if you wish.
Al
« Last Edit: October 20, 2011, 11:36:17 PM by wxtech »
Al Washington, Lexington, Ga.,  NWS Coop station=LXTG1, Fischer Porter, SRG, MMTS. 
CoCoRaHS=GA-OG-1. CWOP=CW2074.  Davis VP2+ WLIP 5.9.2, VP(original) serial, VWS v15.00 p02. ImageSalsa, Win7 & Win8 all-in-one.

Offline SlowModem

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Re: Losing connection at night
« Reply #15 on: October 21, 2011, 02:35:17 AM »
His SIM board is now providing data to my WU site:
http://www.wunderground.com/weatherstation/WXDailyHistory.asp?ID=KGALEXIN1
and to my CWOP site:
http://www.findu.com/cgi-bin/wxpage.cgi?last=24&call=CW2074
Follow the operation of this SIM board if you wish.
Al

Al,

Looks like you're not getting through to WU.  CWOP is updating every 15 minutes it seems.
Greg Whitehead
Ten Mile, TN USA


Offline ocala

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Re: Losing connection at night
« Reply #16 on: October 21, 2011, 03:30:11 AM »
AL FWIW I mentioned earlier in the thread that I had a problem a couple years ago where the ISS would say BATTERY LOW ON STATION 8. After several calls to Davis Tech support they said live with it because it was out of warranty. This message still comes and goes but the battery always checks out fine. This may be related to the battery not making connection.

Offline wxtech

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Re: Losing connection at night
« Reply #17 on: October 21, 2011, 08:21:15 AM »
Early on, Northof60 & Dalecoy said there were 2 problems.  Replacing the supercap will solve 1.  Battery operation isn't reliable.  I'll work on that today.  The SIM board is now on my enclosed porch.  It'll be back on my bench as soon as I finish my 1st coffee.
I'll reheat the battery connections.  It may be an intermittent component in the power supply/regulator, or a bad inner trace of the circuit board.
Does anyone have circuit information on the power section of the SIM boards? 
Al Washington, Lexington, Ga.,  NWS Coop station=LXTG1, Fischer Porter, SRG, MMTS. 
CoCoRaHS=GA-OG-1. CWOP=CW2074.  Davis VP2+ WLIP 5.9.2, VP(original) serial, VWS v15.00 p02. ImageSalsa, Win7 & Win8 all-in-one.

Offline Flag

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Re: Losing connection at night
« Reply #18 on: October 23, 2011, 02:16:44 AM »
Since on the subject of super caps, has anybody ever added a second one as well?

Offline Scalphunter

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Re: Losing connection at night
« Reply #19 on: October 23, 2011, 03:55:28 AM »



Quote
Since on the subject of super caps, has anybody ever added a second one


 If you do an search you would find that has been discuss here before  roughly about year and have ago.

Offline DanS

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Re: Losing connection at night
« Reply #20 on: October 23, 2011, 04:44:42 AM »



Quote
Since on the subject of super caps, has anybody ever added a second one


 If you do an search you would find that has been discuss here before  roughly about year and have ago.


I thought that question sounded familiar because I was interested in seeing the differences in performance myself. This can apply to many applications using solar charged super caps.

http://www.wxforum.net/index.php?topic=4584.0  

Offline Flag

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Re: Losing connection at night
« Reply #21 on: October 23, 2011, 05:05:58 AM »
Maybe my next query would be, why are we bothering with this super cap stuff at all?