AGM battery and cold temps

BirdieJane

We had an AGM battery failure do to cold last weekend. Battery went from a full charge to nothing in 3 hours after the temp dropped to 21 degrees. The Bluetooth app stated the battery temp was at 0. The Renogy tech support stated that once the battery gets so cold, our charge controler would not be able to give accurate readings, it showed 11.6 volts. The next day after temps made it back to 40, the battery began charging via solar again. 
After getting home the battery showed a complete charge, I disconnected the battery and let it rest for 2 hours, then load tested it. It failed the load test, Renogy is sending a replacement. 
We have a 320, the battery is stored in the dog house. So not inside where it is warm. Has anyone had a similar problem with cold temps and an AGM battery?

JohnDanielsCPA

I fully charge my batteries, disconnect them from the T@B and leave them out on my back porch all winter.  Temperatures typically get down into the teens at night and 20s to 30s during the day.  I have never had a problem with them.

ChanW

I have a 6V AGM in my old tractor, outside all winter (for 4 or 5 years now). Never a problem.

The story is though, with a standard wet-cell lead-acid battery, that if it's dis-charged and it freezes, it will likely destroy it.

There wasn't anything drawing power from the battery when it died over that three hour period?

DenisP

My 2018 400 has been covered and stored since Oct. 17th with a fully charged battery and switched off.  I checked the 400 yesterday and the battery is at 100% @ 13.7 volts.  There have been multiple days here in Central Mass. with periods of temps in the 20's and 30's.  
This is in-line with my experience with the AGM batteries in my boat (currently the Optimas are 6 years old.  

BirdieJane

Thanks for the input, maybe it just had a bad cell. The battery was at 13.7 at 7:00 Pm. The Alde was set to 65 degrees. At 10:30 the Alde screen was blinking and indicated low battery. I then checked the Renogy charge controller it said 9.6 volts.

jkjenn

BirdieJane said:

Thanks for the input, maybe it just had a bad cell. The battery was at 13.7 at 7:00 Pm. The Alde was set to 65 degrees. At 10:30 the Alde screen was blinking and indicated low battery. I then checked the Renogy charge controller it said 9.6 volts.

Try using a multimeter to test the reading for acuracy.

N7SHG_Ham

My guess is bad battery. I have had Optima AGM in my pickup for many years and also as the battery bank in a utility trailer with a solar system I designed, about 5-7 years typical in both applications and I have to replace, every battery eventually reaches EOL and needs replacement. I live in an area when zero or below is common in winter, I haven't noticed low temperature being an issue, quite the contrary, battery life is typically shorter in hot climates vs cold.

gregp

I had my AGM 12v battery moved inside.  It will fit behind the power center and the wheel well under the left seat.  That's were mine is located now.  The dealer did the work for me including moving the battery on/off switch.  Greg