I just got done building my first solar system in my travel trailer. I used 2 of the cheaper LiTime 12v batteries in a 24v series. I bought them before I even knew about how you shouldn't allow Lithium batteries to be charged below freezing and why you'd need low temp protection. so that's what I have and where I'm at.
but now, going into winter I know I need to do something about it. here are some options I've thought of:
what if I buy another battery, but this time one of the LiTimes that does have the low temp cutoff built in? and wire that up to the others in series?
(so either replace just one of the 2 batteries so one is the non-low-temp version and the other is the low-temp-cutoff version. or buy 2 more so there is 4 batteries in total 2s2p and only some of them have the low temp cutoff). I believe the batteries are similar enough otherwise that it would be ok to put them in series. Would that break the circuit and effectively give me low temp protection for the 2 batteries I already have?
or what would you do if you were me and needed to add low temp protection to a system you already have?
but now, going into winter I know I need to do something about it. here are some options I've thought of:
- use a holding tank heater pad placed directly under the 2 batteries and turn it on all winter so if it drops below freezing outside, it heats up the batteries enough to stay above freezing.
- cons: what if the thermostat in the heating pad fails to turn on? what if battery gets completely drained to the point that the heating pad isn't powered?
- wrap the batteries in some kind of insulation and cross my fingers that the batteries hidden in that insulation inside my trailer never get below freezing.
- I don't think I can get away with this, I'm sure some night here in utah it will get cold enough that by morning when the sun comes out, the batteries will still be below freezing
- completely turn of everything all winter.
- cons: I was hoping to run an extension cord from my trailer that is parked next to my garage and power all the loads in my garage from my trailer all through the winter. If I turn it off, can't do that
- buy some other device I can put somewhere either on the wire coming in from the panels or on the wires connecting the batteries that has some kind of temperature sensor and can break the circuit if a certain temp gets hit.
- I don't know of such a thing? does it exist?
what if I buy another battery, but this time one of the LiTimes that does have the low temp cutoff built in? and wire that up to the others in series?
(so either replace just one of the 2 batteries so one is the non-low-temp version and the other is the low-temp-cutoff version. or buy 2 more so there is 4 batteries in total 2s2p and only some of them have the low temp cutoff). I believe the batteries are similar enough otherwise that it would be ok to put them in series. Would that break the circuit and effectively give me low temp protection for the 2 batteries I already have?
or what would you do if you were me and needed to add low temp protection to a system you already have?