Battery Insulation Wrap

rcarlson1957

Anyone with lithium battery tried using battery insulation wrap (unheated) for borderline freezing temps when need to charge it? Does it save you a few degrees? Have basic barebones 100ah AmpereTime Lithium battery (no internal heating) and monitor it with Victron's Smart Shunt and Battery Temperature Sense. Normally stay at places with shore power and if getting close to freezing I just turn off battery so WFCO controller doesn't charge battery and turn it on when temp warms back up. I use dedicated external lithium charger to get it to 100% at home since I have older non-lithium controller and use a Victron Solar Controller with portable solar panels when topping off at campground or boondocking and have it set to shut off charging at low temp. Rarely camp in cold weather but do run up against borderline freezing temps and if battery insulation saves you a few degrees thinking it would be worth a try and an inexpensive solution. I've looked at both A/C and D/C powered heat pads but literally all of them say "don't use with lithium." Eventually I'll move everything inside and be less of an issue and free up space in my tub for a second LP tank but is a lot of work and not ready to start that project just yet.

pthomas745

I posted this video from Will Prowse  a few days ago.  He states the batteries produce their own heat while being charged/discharge, and with the addition of a bit of insulation can keep the battery above freezing.  I've looked quickly through the Will Prowse forums and there isn't exactly a good description of the "right" material to use.  Some comments mention a lined box with fiberglass insulation, others use a simple styrofoam cooler.

https://www.youtube.com/watch?v=EaiwxDUY9ho

rcarlson1957

Thanks! I looked at that video too. I went ahead and ordered this kit. Figured it was worth a shot and I'm only out $20 if don't work. https://a.co/d/8IuTuDw. I'll install it and give a shot on trip out to T@bzona this week provide results. 

bergger

I think any type of insulation will help and is better than non.  If its gonna get cold for just the evening throw in a few of the large 18 hour hot hand warmers and you will probably be ok.  The problem with batteries that do not have temp protection built in is that you really do not know when the temp inside has warmed up enough to charge them again.  It may take longer than you think.  In temperate climates where it gets below freezing overnight then bumps back up to 50-60 degrees in the day you'd probably be fine to charge after 2-3 hours of warm temps.  But again that's just a guess.  Since you rarely camp in cold weather some insulation with a bit of overnight heat should help considerably. 

We have a Jackery 1000 and went camping a few weeks ago out of our truck.  Temps overnight got down to 14 degrees.  We had the heater on in our truck topper camper and it was a comfortable 55-64 degrees inside through out the day and night.  However the Jackery was placed by the tailgate.  Based on the amount of overnight freeze in a water bottle placed next to it there I'm guessing it was 25-28 degrees by the tailgate overnight.  The jackery refused to charge, it has cold protection but no internal heaters.  I was surprised that when I brought it back into the house it still took a couple of hours until it warmed up enough to turn it's charging back on.  It sounds like you have a way of monitoring the internal temp on your battery which is great.  That should prevent you from charging it prior it attaining proper temps and damaging it.   

rcarlson1957

bergger, good points. I have a Bluetti 500w solar power bank I use to power an ICECO 20 frig in the back of my truck when I'm going down the road. It's in the very back but under a tonneau cover. Use it in conjunction with one of my 120W solar panels to power the ICECO when boondocking. I hadn't even thought about protecting it. Completely slipped my mind. I need to keep that in mind for it too. Thanks! 

WayneW

We have nearly the same setup as you - 100ah AmpereTime w Battery Sense paired to the Victron controller. I built a box from 1/4” plywood and insulated the battery on all sides except the top with the foil insulation they sell to insulate garage doors. The box floor is a wood/insulation/wood sandwich. The box does have a lid so the battery is entirely enclosed. I think this helps keep the self-generated heat (referenced above) inside the box. It definitely helps in those marginal temps, like down to the mid to upper 20s at night.  I have the Battery Sense set to cut off charging at 1 deg C. 

We haven’t camped in extended cold so I can’t speak to those conditions. We often boondock at higher elevations where it will get to the mid 20s at night but warm up to the 50s or 60s during the day. We haven’t had any problems with cold temp cutoffs (yet). 

rcarlson1957

WayneW Thanks. I'm installing a foam insulating wrap around it tomorrow before we head out to AZ on Fri. I'll test it out. Thanks for the info!