LiFePO4 unit cold storage in detached garage at 20F winter?

[VannCooper81]

Hey everyone, I’m getting ready for my first full winter with my big portable power station. It's a LiFePO4 unit I mostly use for emergency backup and running tools in the garage. My house battery is rock solid indoors, but this portable one has me worried.

I live in the Midwest where our unheated garage can easily sit below freezing, like 20F for weeks at a time. I know the manuals say not to charge lithium batteries below 32F because it causes irreversible cell damage, but what about just storage? It would be a huge hassle to lug the forty-pound beast into the basement for four months, so I'm wondering what the real-world experience is with leaving these things cold-soaked but fully powered off in a detached garage all winter. Is it just a capacity loss issue until it warms up, or am I truly risking permanently damaging the battery's longevity? Any thoughts on a quick-fix insulated box or heating pad to at least get it to a safe charging temperature if I needed to use it for an outage? Thanks!

 

[Boss_Nimzo]

You’re fine leaving it out there as long as it’s powered off and not sitting fully charged. Cold doesn’t kill LiFePO4, charging while cold does. Store it around 40–50% and bring it inside only when you need to recharge. I’ve left mine in an unheated shed all winter and no harm done.

 

[Alan]

LiFePO4 cells can handle cold storage better than charging in cold, but sitting at 20°F for weeks could still stress them over time. Maybe a simple insulated tote with a temp sensor could be a good compromise.