heading south with lithiums

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Compadre

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Apr 24, 2016
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91
We bought a trailer last spring with a single wet cell battery that quickly proved insufficient. Trailer has a fridge that works on AC or DC only, no propane. Has 100 watts of solar. I bought two, 100 ah lithiums and they worked well in summer/fall seasons. As I'm thrifty, I did not buy the heated ones.
I live in the Adirondacks, so its been cold, sometimes single digits or below. I dragged the trailer out from behind the barn a few days ago, getting ready to head south and west for a few months. I'm learning about these LiTime Lithiums. They have low temp shutoff so can't charge in the cold. Brought them into the house, warmed them up and now they're fully charged. I've read they're somewhat useable in mildly cold weather, can discharge but might not charge. I'm looking to leave in 4-5 days and temps will be 20's around here but around 30 when I make it to northern Pennsylvania in 6 hours or so, then keep warming up.
I'm hoping I'll have no issues. Really not much draw, will turn everything off and truck battery should take care of running lights. Other than the slim chance of trailer brakes being used and some minor draws the first night, can't think of why they'd run down, need to be warmed up etc. Won't unhook so jack is not an issue. Might stay in hotel first night, possibly campground if we make it far enough. I'd hate to lug around the old wet cell as insurance for months as its heavy.
What do you think?
Thanks so much.
 
Our Renogy LiFiPO4 battery internally self-heats using charging current to enable charging in cold temperatures. I think they make battery heating pads that can accomplish this too for batteries lacking this internal self-heating functionality. I think that would be better than dragging along heavy LA batteries for backup.

We also modified our small Group 27 100AH LiFiPO4 battery to enable getting 270A from it for up to 20 minutes to feed our 3000 Watt Inverter to create a dry camping 120VAC 20A circuit for our short duration AC appliance needs...coffee maker, hair dryer, microwave oven, toaster oven, toilet bidet seat, vacuum cleaner, etc. We use 200 Watt portable solar panels which accomplish our daily replenishment needs in 4 hours or less. I see that Renogy now has Group 27 300AH LiFiPO4 batteries with high maximum discharge current ratings. Battery technology keeps rapidly improving.
 
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Never had any trouble down to zero with my battleborns but it is probably because of where i keep them. They are supposed to discharge down to -4 degrees and not charge below 25 degrees. Mine are in an exterior compartment that is sealed. It doesnt get direct heat but it does get some heat from the storage compartment next to it. I never measured the temp where they are located so no idea how cold the batteries have gotten.

Can you get heat into where yours are located or maybe wrap the batteries in some insulation?
 
Thanks for the replies,
Batteries reside in a box on the tongue for now, no heated blankets. I just did my best to line the inside of the box with some rigid insulation, will stuff some cardboard and bubble wrap around batteries when they go back in the morning of our departure. If it gets real cold I'll just put one battery in, keep the other somewhere warm, but I'm thinking it'll be 20 or so when I leave and get to high 20's and above after 6 hours or so and then I'll be good. High today of 11 degrees and overnight predicted to 5 below but that's not supposed to last. I've read that lithiums will discharge down to 4 degrees, just not accept a charge below 32. One long day should not eat up 200 ah. Think I'll bring along a charged 12 volt lawn mower battery just in case.
I obviously should have been thinking about this for a while, oh well. Summer project will be to move batteries inside the trailer.
Thanks again.
 
Your trailer brakes are powered from the controller in the truck, so are your running and brake lights. The only way the brakes will draw from the trailer batteries is if the breakaway lanyard is pulled. Other than leaving the refrigerator off until you reach warmer temperatures I wouldn't worry too much about running down the batteries. Though they won't charge below freezing you can continue using them to well below 0 F.
 
@Pedro Dog posted a great video on lifepo4 batteries in this thread.

 
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