Protecting LFP Batteries From Cold

[Sky_Boss]

I'm looking for examples or suggestions for keeping LFP batteries from experiencing freezing temps. My battery bay is pretty wide open to outside temps. I will be working on sealing it off.

I think I've worked out a good deal for the installation of a BMK and new Relion batteries. I'm thinking that I might end up with 3 X 300 AH batteries. To do that I will probably have the battery tray removed and place the batteries on some protective surface (like a rubber mat) between the tray guides. These batteries do not have any heaters.

While we tend to run from the cold we do travel through the higher altitudes of Colorado & New Mexico during October and early November on our way to Yuma. We have encountered freezing temps in each of the 3 years we have done that.

I know that I could seal off the battery bay but I am not sure that will be sufficient protection for the batteries. I'm interested to see if there or folks that have solved this issue without moving the batteries inside.

[jcussen]

https://www.my12voltstore.com/12_Volt_Blankets_s/90.htm
https://www.heatingelementsplus.com/...-blankets.html
With the 900 a/h's you have, the heating blankets 36 watt drain on them would not even be noticeable. Would lay blanket on top and maybe a piece of plywood or foam board on top of blanket, probably your only solution if in an open area.
Used them on my truck camper bed. Kept mattress well above freezing even in sub zero weather.

[vsheetz]

I think you will find the batterues can't be charged at low temps, but can be drawn from.

If daytime temperatures are above charge temp limit, then its ok.

Add another battery to ensure enough capacity.

Is the battery bay adjacent to the conditioned area? It may not get as cold as you think.

An electric heater in the battery bay during genny run time could be an option.

[10 fan]

I just finished my battery box. Took the tray out (the rails come with it) insulated and sealed it. I used a 3" hole saw from battery compartment to the bay behind it (2). I mounted 2 computer fans on a thermostat. 1 blowing out and the other blowing in with a 3" abs 90 notched to fit over the fan. 3" to 2" abs reducer, ran a 2" spa hose from there to the half bath and cut a 3" hole in the sink cabinet thru the floor and stuck the 2" hose thru. My thinking was what ever temperature I'm at will get pulled in the battery bay. I finished Tuesday and left yesterday for Elkhart. 97 deg. outside running 1 air off batteries for 6 hours and it got up to 87 deg in the battery bay. Today was 107 deg. I ran the generator with 2 airs and charged the batteries (178 a) and it got to 87 again. When the temp went down to 95 and the batteries were charged the battery box dropped to 79 deg. Worked better than I thought. Should do the same for heat. I hope. I'll try to post a picture tomorrow.

[Smitty77]

My not moving to Lithium based battery bank this time around, paid off! As one of the few Drop In batteries I was looking at, Lifeblue, has come out with a Low Temperature battery option.

LiFeBlue Battery Prices RV Marine Lithium Ion Battery with Bluetooth Smart Connect

Now, that being said. I believe I will end up retaining my existing battery basement compartment as my installment place for whatever I end up with form the Lithium based batteries. I've already set closed off the egg crate bottom of this compartment, when I went with all AGM. And before installing, say LifeBlue, I'd add extra insulation on the inside of the battery bay (As much for heat from the engine compartment, as from colder days and nights.). And for extremely hot days, say Arizona with 105+ temps... I'll also add some dryer vent like tubes from the battery compartment bay, up into the rear bedroom area. Along with some Pan Cake fans. This way I can circulate air from the AC Rear Bedroom area, into the battery compartment. With a goal to keeping temps in that bay under control.

I have looked for places inside of the coach to install the Lithium based batteries - but I'd rather not take the heat (Pun intended.) form the DW, on using her inside rear bedroom storage. And will do my best to keep make things work with circulation of air, and heat if needed, into a well insulated battery compartment!

Of course, who the heck knows what new tech may come out before I need to replace my relatively new/young bank of Lifeline's!

Best to all,
Smitty

[Itinerant1]

Remember that when it's said that the batteries can't be charged below 32f it means the cell temps of the battery not the ambient air temp. If you close off the compartment and insulate it some what that will help. The cells will have some internal heat just being used. I would be thinking more of the summer heat of the compartment.

Just to give an example these reading are from my battery cell temps (20 cells), front compartment temp of 5th wheel that has had 2" foam board added to the walls, outside ambient temp.



Even at the lower ambient temps the battery (cells) are actually warmer.

Having the ability to see cell temps can be very helpful.

Most of the drop ins on the market now that folks are using have the ability to protect themselves from low temp charging anyways.

[10 fan]

Better internet this morning maybe picture will load. It's only been 2 days but so far so good. Thanks for the info on cell temp compared to battery box temp, had not thought of that.

[RKins]

Originally Posted by Smitty77

My not moving to Lithium based battery bank this time around, paid off! As one of the few Drop In batteries I was looking at, Lifeblue, has come out with a Low Temperature battery option.

LiFeBlue Battery Prices RV Marine Lithium Ion Battery with Bluetooth Smart Connect

Now, that being said. I believe I will end up retaining my existing battery basement compartment as my installment place for whatever I end up with form the Lithium based batteries. I've already set closed off the egg crate bottom of this compartment, when I went with all AGM. And before installing, say LifeBlue, I'd add extra insulation on the inside of the battery bay (As much for heat from the engine compartment, as from colder days and nights.). And for extremely hot days, say Arizona with 105+ temps... I'll also add some dryer vent like tubes from the battery compartment bay, up into the rear bedroom area. Along with some Pan Cake fans. This way I can circulate air from the AC Rear Bedroom area, into the battery compartment. With a goal to keeping temps in that bay under control.

I have looked for places inside of the coach to install the Lithium based batteries - but I'd rather not take the heat (Pun intended.) form the DW, on using her inside rear bedroom storage. And will do my best to keep make things work with circulation of air, and heat if needed, into a well insulated battery compartment!

Of course, who the heck knows what new tech may come out before I need to replace my relatively new/young bank of Lifeline's!

Best to all,
Smitty

I think you'll be inviting rodents into your bedroom by doing this.

[Smitty77]

"I think you'll be inviting rodents into your bedroom by doing this."

Critters can get into many places, even places that I might feel I've sealed off well! So always a possibility, and vigilance will be required. (And is anyway's, as rodents can enter a coach from many areas!).

My battery bay is relatively sealed off well now anyways. When I put this batch of Lifeline Chassis and House batteries in - I added plexiglass to the bottom of the battery bay, to do a better job of protecting the bay from the elements, and water being tossed up from the Tag and Duals. (Compartment is staying dry now, and dust has been reduced by a good 95% +) When I go to Lithium. I'll seal the few penetration holes for cabling, and also insulate all around. The outside cabinet door of our coach is pretty well insulated already, but I'll add insulation to this door too. My thought were to cover the top and bottom of the probable run of either 4" or 6" ducting, with wire mesh. Thinking one fan blowing blowing in, and the other fan sucking out, of the basement pay. With manual switches to activate. Our coaches non slide side, has a dresser directly over the battery basement bay. The dresser has about 2" of dead air space below the drawers. So I thought by drilling multiple 1 to maybe 1 1/2" holes into the base board of the cabinet, that would allow air flow too and from the heated/ac space of the bedroom.

But, who knows, I may just see how things go. It's the AC to protect agains heat, that is my primary goal here. I think by keeping the batteries warm in colder temperatures, is an easier item to control. It's the keeping the cool in hotter temps that I'm interested in.

And frankly, heat is not the friend to any battery, including my current Lifeline's - so not unique to Lithium based!

Best to you and all,
Smitty