I have two 200ah smart lithium ion batteries in my motorhome and want to leave them in place for the winter. Will lithium batteries get damaged if they are frozen? Will they be “okay” and usable next spring? I will charge them to 100% and turn off my negative disconnect. The temperatures in winter can be below zero degrees fahrenheit for over a month and sometimes below negative twenty fahrenheit for a week or longer. I have monitored my system for over a month now with the disconnect off and had no voltage discharge and they maintained a 60% charge in that time. It has been around thirty degrees over the past month. I will not attempt to use or charge the batteries while they are “freezing”. The batteries are difficult to remove from the motorhome, but they can be removed with hours of work and disassembly of cabinetry. I don’t want to damage them if cold is a problem.
I have read you should actually discharge them to 50% when storing below freezing. The self discharge rate is actually really low, less than .5% per month. Perhaps a smarter person on this site can explain why. Of course no charging.
The manual or the datasheet state that storage is OK down to -45degC, I only have access to European version, I calculate this as -49degF.
As above, best to store them at 80% or below, the datasheet states that they will last 12 months when full at 25degC, this will.be shorter when starting from 80% and cooler.