Topic: low battery problem

[weathergirl]

Ok, this is ridiculous. I just replaced the battery in my ISS last week, and now my console is saying the battery is low again. 
What could be causing this?

[weathergirl]

OK, I put the console through setup again and the low battery message disappeared. We'll see what happens.

[d_l]

A failed supercapacitor (shorted out?) can drain the ISS battery in a short time by putting a constant current draw on it.

[weathergirl]

I find it interesting that this problem arose just after I changed the battery. The previous battery lasted for quite a long time.  I did get a new SIM board a year-and-a-half ago. This reminds me of a thread I started here-

http://www.wxforum.net/index.php?topic=336.msg2200#msg2200

Same problem, but with the ISS now. This morning, the low battery message displayed again, I placed the console through setup again, and the message disppeared, again! So, could this be the supercapacitor?

[d_l]

That would be terrible if the supercapacitor failed on a replacement SIM board.  There was a period where Davis had a manufacturing problem (rough handling of the supercapacitor leads during board insertion) that caused premature failure, but I would think a SIM board from 1.5 years ago would have been made after they fixed that manufacturing problem.

Is there any chance the new lithium battery was weak or bad before you installed it?  I think I'm going to routinely voltage test replacement batteries as a standard pre-installation precaution from now on.

Someone correct me if I'm wrong, but I think the only way (the best way) to check for a failed supercapacitor is a visual inspection for corrosion/leaking fluids after removal of the white plastic SIM cover.

[weathergirl]

Someone correct me if I'm wrong, but I think the only way (the best way) to check for a failed supercapacitor is a visual inspection for corrosion/leaking fluids after removal of the white plastic SIM cover.

That's the first thing I checked for when I was replacing the battery, and it looked just fine.  I will place a fresh battery in it and see what happens, but then again, that's what I went through in the other thread, I kept replacing the battery, then finally gave up on using the anemometer transmitter

[d_l]

Oh duh!  I didn't pick up that you had replaced the board on an anemometer transmitter (not ISS) until I re-read those posts. I think your ISS could be from that supercapacitor problem era.

So the one in the anemometer transmittor failed fairly fast (a few weeks?) and the one in your ISS might have taken a few years?

[weathergirl]

No, I didn't replaced the SIM board on the anemeometer transmitter at all, I changed it on the ISS. Sorry I wasn't clear on that

[ocala]

Ann Marie I have been getting that same message for  a few months. When I put the battery in it was 3.23 volts. When I checked it a couple weeks ago it was 3.22 volts. The ISS is sending a bogus message in my case.
That may be what's going on with yours. Check the voltage on the battery. If the one you put in is ok then you are just going to have to live with that message even though it's an error.

[weathergirl]

Thanks. I looked in VP Live and my battery is 4.65 volts, so it looks like it's not being drained, so I'll just put up with
the message

[d_l]

Umm...  Ann Marie, isn't the 4.65V the reading on your C cell batteries in your console or Envoy?   A lithium 123 battery should be closer to 3.24V if new.  I don't know what minimum voltage level in the lithium battery would cause transmission problems at night if the supercapacitor was shot.

[weathergirl]

Umm...  Ann Marie, isn't the 4.65V the reading on your C cell batteries in your console or Envoy?

I'm not sure, so where would I find out the volts on the ISS battery?

[d_l]

I think you have to pull it out and test it with a multimeter.  The Alarm and Battery screen in WeatherLink is only a Pass/Fail-type test.

[Aardvark]

I'd go with the failed super cap.. but also check the solar panel, that it is charging the super cap.   I found the below information on the ISS and console, I'd check the solar panel and also check that the test switch on the dip switch on the ISS board is in the off position... that can drain both if not in the off position.   That can happen... maybe gremlins  but it is also worth a check.....

the specs:
Integrated Sensor Suite (ISS)

Operating Temperature . . . . . . . . . . . . . . . . . . . . . . . . . .-40� to +150�F (-40� to +65�C)
Storage Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . -50� to +158�F (-45� to +70�C)
Current Draw (ISS SIM only) . . . . . . . . . . . . . . . . . . . . . . 0.14 mA (average), 30 mA (peak) at 4 to 6 VDC
Solar Power Panel (ISS SIM / Fan-Aspirated) . . . . . . . . . . 0.5 Watts / 0.75 Watts
Battery (ISS SIM /Fan-Aspirated) . . . . . . . . . . . . . . . .. . . CR-123 3-Volt Lithium cell / 2 - 1.2 Volt NiCad C-cells
Battery Life (3-Volt Lithium cell) . . . . . . . . . . . . . . . . . . . . 8 months without sunlight - 2+ years on solar
Battery Life (NiCad C-cells) . . . . . . . . . . . . . . . . . . . . . . . 1 year
Fan Aspiration Rate (Fan-Aspirated Only) . . . . . . . . . . . . 190 feet/min. (0.9 m/s) (full sun), 80 feet/min. (0.4 m/s) (battery only) (intake flow rate) 500 feet/min. (2.5 m/s) (full sun), 280 feet/min. (1.4 m/s) (battery only) (sensor chamber flow rate)
Connectors, Sensor. . . . . . . . . . . . . . . . . . . . . . . . . . . . . Modular RJ-11
Cable Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-conductor, 26 AWG
Cable Length, Anemometer . . . . . . . . . . . . . . . . . . . . . . . 40' (12 m) (included), 240' (73 m) (maximum recommended)
Wind Speed Sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . Large wind cups with magnetic switch
Wind Direction Sensor . . . . . . . . . . . . . . . . . . . . . . . . . . Wind vane with potentiometer
Rain Collector Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . Tip bucket, 0.01" per tip (0.2 mm with metric rain adapter), 33.2 in2 (214 cm2) collection area
Temperature Sensor Type. . . . . . . . . . . . . . . . . . . . . . . . Thermistor
Relative Humidity Sensor Type . . . . . . . . . . . . . . . . . . . . Film capacitor element
Housing Material . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . UV-resistant PVC plastic

Console

Console Operating Temperature . . . . . . . . . . . . . . . . . . . +14� to +140�F (-10� to +60�C)
Display Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . +32� to +140�F (0� to +60�C)
Storage Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . -5� to +158�F (-20� to +70�C)
Current Draw . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.90 mA average, 20 mA peak, (plus 120 mA for display lamps, plus 0.125 mA for each optional wireless transmitter received by the console) at 4 to 6 VDC
AC Power Adapter. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 VDC, 900 mA, regulated
Batteries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 C-cells
Battery Life . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . up to 9 months
Connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Modular RJ-11
Housing Material . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . UV-resistant PVC plastic
Console Display Type . . . . . . . . . . . . . . . . . . . . . . . . . . . LCD Transflective
Dimensions (console: length x width x height; Display: length x height)
Console with antenna . . . . . . . . . . . . . . . . . . . . . . . 10.375" x 1.5" x 6.13" (264 mm x 38 mm x 156 mm)
Console with antenna extended up . . . . . . . . . . . . . 10.375" x 1.5" x 9.8" (264 mm x 38 mm x 248 mm)
Display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.94" x 3.375" (151 mm x 86 mm)
Weight (with batteries) . . . . . . . . . . . . . . . . . . . . . . . . . . 1.88 lbs. (.85 kg)

[ocala]

Umm...  Ann Marie, isn't the 4.65V the reading on your C cell batteries in your console or Envoy?

I'm not sure, so where would I find out the volts on the ISS battery?

Try a hardware store or something like a Radio Shack. I'm sure they have one behind the counter that they could use to test your battery.
They are relatively inexpensive and if the message you are getting is bogus at least you have the meter to periodically check the voltage.

[weathergirl]

Well, I don't know what happened, but I did not get the low battery warning this morning. Let's hope it stays that way!

[ocala]

Well, I don't know what happened, but I did not get the low battery warning this morning. Let's hope it stays that way!

LOL
That sounds just like mine.
Here today gone for a week. Back next week for a few days then gone again.

[weathergirl]

If it has to be that way, then I'll live with it, lol

[Aardvark]

the battery warning is in the console, one thought could be that the console is at fault.  I replaced batteries and was told that other than repowering the whole thing, the warning cleared at midnight....   

Maybe  if the battery , after one of those low readings comes up is still good, the error is in the console.

[ocala]

the battery warning is in the console, one thought could be that the console is at fault.  I replaced batteries and was told that other than repowering the whole thing, the warning cleared at midnight....   

Maybe  if the battery , after one of those low readings comes up is still good, the error is in the console.

After speaking at length with Davis it was concluded that the ISS is sending a bogus message. They didn't think the console was at fault.
Said I could send it in to be fixed or just live with it. Chose to live with it. 

[Aardvark]

sometimes living with it is the easiest.. 

[TeaysValleyWV]

My console ticker started showing low battery on station 1 this morning.  I had replaced the 123 lithium battery in January when it quit transmitting with no warning what so ever.  So, I replaced it again today not wanting to miss data like last time.  The message went away after replacing it.  Instead of throwing the old battery away, I checked it with a voltmeter and it shows slightly over 3 volts.  I'd say it was still good considering the time span and the voltage.

My original battery lasted from August of 2006 to Spring of 2008.  I replaced the second one in January 2009 when it outright quit.  I didn't check the voltage on this one because I assumed it was dead.  I don't trust the warning message thingy anymore and was planning to replace both the annemometer trasmiiter battery and the ISS this Fall anyway.

Does anyone know what voltage triggers the warning?

[wxtech]

Does anyone know what voltage triggers the warning?

I set up an experiment on a VP2+.  2.87 volts on the battery and all works OK.  2.85 volts at the battery and the "LOW BATTERY ON STATION 1" displays.  The low battery warning on the console goes away 1 update after the voltage is back up to normal.
At 2.48 battery volts, the test led does not flash; 2.7 volts it does flash but data was not received during a short test period.
I measure 3.28 volts (under no load) on a fresh battery.  My VP2+ in use (under load) measures 3.02 volts.

[TeaysValleyWV]

Does anyone know what voltage triggers the warning?

I set up an experiment on a VP2+.  2.87 volts on the battery and all works OK.  2.85 volts at the battery and the "LOW BATTERY ON STATION 1" displays.  The low battery warning on the console goes away 1 update after the voltage is back up to normal.
I measure 3.28 volts (under no load) on a fresh battery.  My VP2+ in use (under load) measures 3.02 volts.

Hmm...In that case assuming the load would be a constant 0.26 v, I could have been below the threshold for the warning.  I guess the next question would be at what voltage does it quit?

[wxtech]

Does anyone know what voltage triggers the warning?

I set up an experiment on a VP2+.  2.87 volts on the battery and all works OK.  2.85 volts at the battery and the "LOW BATTERY ON STATION 1" displays.  The low battery warning on the console goes away 1 update after the voltage is back up to normal.
I measure 3.28 volts (under no load) on a fresh battery.  My VP2+ in use (under load) measures 3.02 volts.

Hmm...In that case assuming the load would be a constant 0.26 v, I could have been below the threshold for the warning.  I guess the next question would be at what voltage does it quit?

The voltage drop from 3.28 volts no load to 3.02 volts in operation is due to the internal resistance of the battery.  A fresh battery has a low internal resistance.  That resistance increases with use.  The voltage decrease is due to the battery internal resistance increasing.
The SIM won't transmit at 2.48 volts on the battery.  This is with the solar panel disconnected.
The rated voltage of the battery is 3 volts.  So I assume that in normal operation the battery will supply the specified current while maintaining 3 volts.  Almost any current drawn will cause the battery voltage to drop to 3 volts.