LiFePO4 heating pad for cold temperatures

[ConnerLabs]

If those are anything like the Shorai LFP battery I had on a motorcycle a few years back, can run into big problems with starting when temps drop into 40s and 50s. Also with the nonsense "lead acid" equivalent numbers.

I would also recommend against replacing a lead acid car battery with drop-in LFP. Heard so many horror stories. It might start your car in low temps, but then the alternator (or DC-DC in an EV) tries to charge it, the BMS does its low temperature charging protection and cuts off, car electrical system freaks out.

 

[Supervstech]

I would also recommend against replacing a lead acid car battery with drop-in LFP. Heard so many horror stories. It might start your car in low temps, but then the alternator (or DC-DC in an EV) tries to charge it, the BMS does its low temperature charging protection and cuts off, car electrical system freaks out.

Yeah, if you do id tie in a motorcycle battery or similar to even out loss.
I use an lfp in my wagon, but its an 87, so hardly any computerized stuff...
And it has 300W solar on the roof rack.

 

[outboard1196]

Here's my beta test, I stuck an RV heater pad to some flashing and burried it in a few inches of sand inside a cooler. Seems to have a stabilized, running for 7-8 minutes every 2 hrs but outside temps are in the 40s F have some single digits F temps coming up.
I have some heater pads with an actual temp controller coming which I feel will be better but I'm curious how this goes for now.

 

[HRTKD]

If that tank pad has a built-in thermostat like most RV tank heaters do, it's based on water being in the tank. I would not use that on a battery.

Do you get a reading on how hot the pad became?

 

[outboard1196]

If that tank pad has a built-in thermostat like most RV tank heaters do, it's based on water being in the tank. I would not use that on a battery.

Do you get a reading on how hot the pad became?

The pad is in the sand not on the battery directly.
On at 45f off at 65f.

 

[HRTKD]

On at 45f off at 65f.

Theoretical or did you observe that yourself?

 

[BarracudaBob]

How about seed germinating heating pads ?

Thermostat Controller, 40–108 ºF up to 1K
They have a lower output but come in different sizes.

 

[outboard1196]

Theoretical or did you observe that yourself?

Not scientific, but held my hand on it got slightly warm then turned off. Certainly not hot by any means.

 

[outboard1196]

How about seed germinating heating pads ?

Thermostat Controller, 40–108 ºF up to 1K
They have a lower output but come in different sizes.

No AC available.
I did mention I have another solution.

 

[outboard1196]

So the rv heater pad wasn't quite keeping up, I think it was too wide of a temperature swing.
Battery was around 40f and outside was 20f.
Just put in two 50w pads with w1209 heater controller with 50f on and 60f off. Forgot to take a picture but I stuck them to aluminum flashing like above and burried it in the sand. Well see how it does.
Also the store bought sand was way too wet started condensing on the inside of the cooler, spent yesterday drying it out on the grill.

 

[Daddy Tanuki]

So the rv heater pad wasn't quite keeping up, I think it was too wide of a temperature swing.
Battery was around 40f and outside was 20f.
Just put in two 50w pads with w1209 heater controller with 50f on and 60f off. Forgot to take a picture but I stuck them to aluminum flashing like above and burried it in the sand. Well see how it does.
Also the store bought sand was way too wet started condensing on the inside of the cooler, spent yesterday drying it out on the grill.

its hard to win these days cousin... but we soldier on.

 

[outboard1196]

its hard to win these days cousin... but we soldier on.

You don't know till you know, then you know.


New heater pads are working good. Might need some tweaks but it's been cold and windy here low about 12f and high 25f for 3 days lowest smart shunt temp was 38f. The battery I will be using has internal heaters for backup. 3 days used about 80ah which isn't bad.

 

[outboard1196]

Finished up the cooler and its in use now.
Need to tidy up the wiring. Current ambiant temp 21f inside is 40f

 

[outboard1196]

Couldn't of picked a better time to set this up. Had it get down to - 5f a few nights temp in the box got down to around 35f and internal battery temp sensors down to 45f. Lost a bit of heat retention when running the cables through the side. The cables sure do suck the heat out, the smart shunt temp sensor on the battery terminal would go below 32f until charging started.