Battery Heater

[Cosmo]

I was thinking a much smaller battery in very cold conditions running almost continuously. 400AH is quite the a battery. Thanks so much for explaining. I was off in the trees looking for coconuts on this one!

Regards
=Cosmo

[foxontherun]

Good afternoon,
Hope all had a good Christmas holiday yesterday. Santy Claws must have thought I have been good this year so I didn't get any coal for Xmas. I got battery stuff, ha! I have ordered two of these batteries: https://www.amazon.com/dp/B0BXSSHW5V?re ... tails&th=1

I was going to attempt the build your own but between buying the cells, necessary equipment that I don't have, and a somewhat fear of burning the trailer down should I do something stupid building it I came across these two batteries which for $150 more than the DIY was worth not having that headache assuming what I ordered work out, ha!

I need some info on the bee hive heaters. This link: https://www.amazon.com/GAOHOU-Electric- ... NrPXRydWU= is what I found posted earlier in this thread. If my math is right the pads are roughly 4x5 inches each. I would assume I need to order four to have two each under each battery the batteries I ordered are supposed to be 7.6 in W x 13.7 in L. Would this be correct?


I ordered this temp control: https://www.amazon.com/dp/B019I3YCFS?ps ... ct_details from a link I found on the forum. Is there anything additonal I need to have to make sure I have what is needed to heat the batteries?

All thoughts and ideas would be greatly appreciated.
Harry

[bdosborn]

I used 4 pads under my battery and that's been working well for me.



I'm using the same digital thermostat you have shown in the link and I'm happy with it.
Bruce

[tony.latham]

Regards
=Cosmo

Damn. May ol' Cosmo rest in peace. He was going to try to make it west this coming summer, and we were going to camp...

Tony

[lfhoward]

RIP, Cosmo. He and I had chatted about camping in winter with our Propex heaters and he was working on another video about that. He was a good dude.

[foxontherun]

My condolences to his family and those who knew him.

Bruce, thank you for the info on your setup and confirming how many heater pads that I would need. I am glad to hear that the thermostat works to your satisfaction as well. I appreciate it.
Harry

[bdosborn]

Almost forgot; one thing that goes a long way towards lowering how much energy you use heating your batteries is insulation. My wife made a battery cozy out of thinsulate for the batteries and it helps a lot. I take it off in the spring and put it on in the fall.


Bruce

[foxontherun]

Bruce, that is a really cool idea.

Do you leave these on when you are using the van or are the covers when van is in storage mode? I really like that idea.

At home is where the beehive heaters will probably be most useful for us when the trailer is sitting in the yard, I do have it hooked up to power for the heater but should the power go out, I want the batteries to be able to keep beehive heaters going just to protect the batteries should the temps get to cold. Of course I just have to remember to keep an eye on the charge level, ha! We live in TN so real cold doesn't happen real often, however, it was down to minus 1 last December which thankfully didn't last too long. We are typically more around freezing or above for most of the winter.

Thanks!
Harry

[bdosborn]

My batteries are in a van that gets HOT in the summer time. On top of that, batteries get warmer when you charge them. Heat is the biggest accelerant to LiFePO4 degradation. It speeds up the electrolyte decomposition that binds lithium in a non-reversible chemical reactions. The result is less capacity due to Lithium reduction, higher equivalent cell impedance, and greater cell self leakage rate. Above 35C it starts to get bad, above 50C it is very bad. So I take the insulation off when I know I wont be using the heaters, to try and keep the batteries cooler.
Bruce

[foxontherun]

Very good to know about the cell degradation; thank you for sharing that, very helpful to know that.
Harry

[User137596]

Hey gang, don’t have much to add to this discussion, but I can say cold weather temperatures really screw up charging voltages and time. The deep cycle included with my new trailer looked to be maybe 6 months old and was about 75 or 80 percent charged. I messed around with charging it outside and it wasn’t doing too much. I decided to see if the controller and shore power would plus it up. Since it was ~ above 80% it reverted to 13.6 volts, a very slow rate of charge. I gave it about 3 days and gave up. It was 16° F. at one point overnight. Since the last 10% of the charge represents about 30% of the capacity it is worth utilizing.

Bringing the battery inside and messed with it on the bench, and it took about 3 days at 68° to charge up using 3 different chargers. Each one has a different idea of how to charge. New lead-acid deep cycle batteries are resistant to both providing and accepting current until several cycles have passed, but this thing is pretty slow!

I think it will give good service regardless but it became really obvious right away keeping the battery warm - any battery type, though especially flooded lead acid - will save a lot of time when charging for boondockers. This temperature compensation business is the tail wagging the dog with charging for sure. I come from an auto maintenance background, running a battery down by 40 or 50 percent is not done, and the automotive chargers aren’t really setup for daily charging at that level of amps

[foxontherun]

Need some advice on battery temp sensor location; I had planned to put the sensor between the batteries. However, since my batteries are not DIY Lifepo's there is a rather large gap between the batteries (narrow at top and wide at bottom, (1/2" max).



I plan to wire the beehive heaters all together (unless that is a bad idea). So, in the gap area, I am thinking taping the sensor to the battery closest to the side door. Figured that battery might get colder faster being next to the side door. These are the heaters and temperature sensor I am using:

Beehive eaters for batteries: https://www.amazon.com/dp/B0794V5J5H?ps ... ct_details
Temp sensor: https://www.amazon.com/dp/B019I3YCFS?ps ... ct_details

Any thoughts/suggestions on best and proper way to do this would be appreciated.

Thanks,
Harry

[bdosborn]

I have my sensor clamped to the battery terminal as that seems to have some thermal mass that keeps the temperature from bouncing around like crazy. I have the heat come on at 36F and off at 40F.
Bruce

[foxontherun]

I have my sensor clamped to the battery terminal as that seems to have some thermal mass that keeps the temperature from bouncing around like crazy. I have the heat come on at 36F and off at 40F.
Bruce

Good evening Bruce, do you have a picture of that by chance? I wasn't able to view terminal posts very well in your post earlier in this thread on Dec 26, 2023 4:49 pm. Sounds like a good idea.
Thanks,
Harry

[bdosborn]

I'm using a Victron temperature sensor and the heater relay is controlled by a Victron Cerbo GX. The temperature sensor is all set up to clamp to the battery terminal.



Bruce