How can I save my batteries?

[Offgridummy]

I have 2 chins 12v 100ah lifepo4's. It's been brutally cold here lately. I'm using a victron smartsolar mppt and I have the battery temp sensor. The mppt was set to cut off charge at 5c (probably not low enough?) Came out to the camper and I was showing around 11v, apparently it had been so cold lately that the mppt wasnt charging due to the cut off temp. I can tell the batteries had cycled on and off a few times. I ran heat in the trailer all last night. This morning my victron Mppt doesnt show any voltage all.

Currently not running a shunt. Did I mess the batteries up? How can I recover these?

 

[Bobert]

I have 2 chins 12v 100ah lifepo4's. It's been brutally cold here lately. I'm using a victron smartsolar mppt and I have the battery temp sensor. The mppt was set to cut off charge at 5c (probably not low enough?) Came out to the camper and I was showing around 11v, apparently it had been so cold lately that the mppt wasnt charging due to the cut off temp. I can tell the batteries had cycled on and off a few times. I ran heat in the trailer all last night. This morning my victron Mppt doesnt show any voltage all.

Currently not running a shunt. Did I mess the batteries up? How can I recover these?

Are your batteries stored outside?Do your batteries have low temperature cutoff?

 

[Bobert]

Exactly what temperature is “brutally cold” for you?

 

[Offgridummy]

The batteries are inside the camper. We have been getting lows in the teens and daytime temps in the 30's but also a lot of wind. A bottle of water was frozen inside the camper. Yesterday the DC lights would come on, but today nothing. I think the chins has a built in bms that shuts them down at low temp and low voltage.

 

[Offgridummy]

Ok just went out and checked on them. They are back! 11.04v

 

[Bobert]

If it’s not to much trouble I would put the batteries inside or in some other fashion make sure they are warm enough and fully charge them . It’s best to have your batteries at a high state of charge if they are going to be used when it is cold. The voltage drops when they get cold and they can hit low voltage disconnect without being drained all the way. If you have low temperature cutoff they may not charge until they are fairly warm. The Bargain Lifepo4 batteries I use don’t start accepting charge till they are in the 40 to 50 degree temperature range once low temp has been tripped.