Lithium Battery heater

^Only if you’re buying!

pianotuna wrote:
Use Lithium Titinate batteries, or SiO2

Couple little heat pads are way cheaper for occasional need.
I agree with you though if you’re camping in -37 deg weather, which only 0.00001% of RVers do.

The LifePo4 batterys I got were in 4.2v cells rated at 280ahr. EVE grade A.
Building the two battery's give me about 560total hrs probably only 530ahrs or so.
They do not come with heaters.
Total cost all in for everything was about 2k. Worth it in the long run.

My BMS also has a temp reading via B-tooth as well.
Alot more bang for your buck going this way.

You can build your own heater:

DIY Battery Heater See post #14

Bruce

We rarely see freezing temps (one of the reasons we live full time in our "wheel estate"). ;) And our SOK batteries have built in BMS that won't allow charging when the INTERNAL battery temperature drops below freezing. Hence, I don't see a need for battery heaters.

IMO, it's just a matter of time before all 12v, consumer-grade, lifepo4 batteries come standard with internal heating pads. It's far from rocket science, plus the costs for manufacturers to add a few silicone heating pads and a BMS with a heating pad terminal are minimal. Consumers wanted low-temperature cut-off, they got it. Internally heated batteries are next.

On a sidenote, some may not know that cold weather operation of lifepo4 batteries negatively affects discharge performance in addition to charge performance. Dropping the temperature of a lifepo4 battery from 77f to 32f can reduce the battery's total ah output by approx. 10%. This means a battery that produces 100ah at 77f may only produce 90ah at 32f. Not only is the ah output reduced, the maximum continuous discharge current the battery can safely produce is also reduced. In other words, powering a microwave while your lifepo4 battery sits in sub-freezing temps may not be doing your lifepo4 battery any big favors.

During the winter we keep our lifepo4 internally heated to a constant 55-60f (cell temps), 24/7. We do this to: 1) maximize ah output (any increase here helps power the heating pads), and 2) lower the risk of reducing cycle life with any high current discharges. Plus, it goes without saying . . . we also retain full charge capability, 24/7, too. For us, a win-win-win.

otrfun,

Is there a reason for 55 to 60 as opposed to 77 f?

^Because they warm up with use and would suck more juice being heated to 77deg continuously when not used?

pianotuna wrote:
otrfun,

Is there a reason for 55 to 60 as opposed to 77 f?

Very small performance drop to 50. Performance drop is a curve, not linear. And of course most things stop around 32. Heating to 77 is fine except uses more energy while providing little benefit vs 55 zone.

Time2roll,

Thanks.