Storing Lithium batteries over winter

[WinniMN]

Greetings,

In previous years, I would bring the flooded deep cycle NAPA batteries indoors and connect to a Genius 10 charger/maintainer.

This summer I swapped those for 2 LiFeBlue Ultimus LiFePO4.

We are about to winterize and cover the View but i am not sure how to store the LiFePO4 batteries.

These batteries have an on/off switch.

If I disconnected them from charging sources and turned them off, would they be OK in Minnesota temps that can get as low as -20F left in the coach? I would probably take it out of storage in late March.

Thank you for your help

Bruce

[Marine359]

Check the manual that came with your batteries Bruce.
Most, but not all LFP batteries can be stored for a limited time down to -20F. My first LFP said 30 days. My current one has self-heating, which I have programmed to heat only when I want to charge it. It must be higher than 32F to charge. Living in Minnesota or the Arctic (both about the same, correct?), winter ambients can easily exceed manufacturer specs. Why risk it? They aren’t that heavy. Deplete charge to 60% SOC, and bring them indoors. You can store them like that until it thaws out in Minnesota (August?). And you don’t need to keep them on a tender. If you want to put them back in the RV and charge them back up while is still below freezing, you can just use a hair dryer and a nearby thermometer. Or, get a 12v thermostically controlled heating mat. Throw it on the batteries, and let the batteries run the mat.

[WinniMN]

Originally Posted by Marine359

Check the manual that came with your batteries Bruce.
Most, but not all LFP batteries can be stored for a limited time down to -20F. My first LFP said 30 days. My current one has self-heating, which I have programmed to heat only when I want to charge it. It must be higher than 32F to charge. Living in Minnesota or the Arctic (both about the same, correct?), winter ambients can easily exceed manufacturer specs. Why risk it? They aren’t that heavy. Deplete charge to 60% SOC, and bring them indoors. You can store them like that until it thaws out in Minnesota (August?). And you don’t need to keep them on a tender. If you want to put them back in the RV and charge them back up while is still below freezing, you can just use a hair dryer and a nearby thermometer. Or, get a 12v thermostically controlled heating mat. Throw it on the batteries, and let the batteries run the mat.

thank you, I did find that data sheet and the low temp is 20 degrees. So, i guess they will be coming in.

Bruce