Lithium Battery over winter

[happy-THOR]

Hoping this is my last Lithium Battery question before install.

We live where winters get below 20 F for several weeks. With a lithium battery that does not have built in heat and is stored in the cold I believe we should not try to charge it. In this situation is it sufficient to charge the battery before the hard freeze and simply let it sit throughout the winter. The battery we are looking at states a 3% per month discharge rate. We would let it sit in the cold for 5 months without any maintanence. Once the temps rose above freezing we would then recharge it

Is this an adequate plan for a lithium coach battery?

 

[Chateau_Nomad]

Most modern LiFePO4 Battery Management Systems are programmed to prevent charging if the internal battery temperature is below 32°F.

Since your battery doesn't have internal heating, it "shouldn't" charge at below freezing temperatures.

Most LiFePO4 batteries can safely discharge at below freezing without harming the battery.

Notice my emphasis on charging vs discharging. AND... the BMS programming is key. You should go by your batteries manufacturer specs for all of these.

For instance... I'm in Ohio where temperatures are often below freezing in winter, and CAN get to below 0°F for brief periods. My LiFePO4 batteries are BMS controlled to prevent charging below freezing... but they also have heaters. I leave them in year round as they are very difficult to remove... they are rated for use below freezing (discharging) and since the BMS controls both heaters and charging, I have no worries... they have been fine over two winters.

Bottom line... any appreciable capacity loss from cold weather exposure in my case is extremely miniscule. Over a 10 year span I doubt it's even relevant.

Your situation may be different. If your batteries are easily removable, they can be stored at 80% SOC in your basement (for example) where temperatures are well above freezing. If this relieves stress of worry, go for it!

 

[macdaddy1111]

I installed Lithium batteries to run camers on poles in salt water oyster beds 4 years ago and they still work like a champ. Went down in teens multiple times.

I have friends in new England that just turn off barrel switch i install for them when they winterizing rig and they have no issues

 

[PS89]

Just charge the LiFePO4 battery to at least 60-70%, disconnect it (to prevent parasitic draws) and walk away until the spring thaw.

 

[happy-THOR]

Thank you for the replies. You all sharing your knowledge is appreciated.

I have read that the batteries do not like being at 100% or at 0% for very much time.
We will plan to get to around 80% charge state while temps are still above freezing and let them winter over.

 

[rudyhehn]

Agree they can sit fine over the winter. One source says temps <-10F can be a problem but that is a rare event in most locations. Everyone seems to agree that 80% storage charge is fine. Some say 100% is fine too but some sources say don't use max charge when storing. Be sure to disconnect from the RV to avoid slow draws.

 

[happy-THOR]

Thank you for the reply! For us it is 5 plus months before the cold sets in.
At least in this info, I am ready for winter.

 

[dkoldman]

I think the Chateau is right. In my case I had my 1st winter last year with my 300ah Lithium battery. I did NOTHING different. I figure worse case I destroy the battery at $327. I have no battery heater, and I will not disconnect it. It is normally always plugged in so it will be in float mode or some type of charge. When temp goes below freezing I trust my BMS to it's thing. If it did and put battery to sleep, I never noticed, never had to do anything to wake the battery etc.

One of the reasons I doubt cold temperatures will be an issue is because many people have automatic gates that have lithium batteries with solar charging. They use the gates year around and they are being charged year around as well when the BMS allows.

Also, my Lithium battery does not list a discharge rate based on %. 3% sounds very high to me if it is no load. My Lithium battery does not discharge at all of my Use Store switch is OFF. Similar for my Lithium Power Stations. If they are OFF and SOC is 100%, a month later it will still be 100%.

 

[happy-THOR]

Thank you. I am planning to leave it over winter not connected to anything.
Even if it had a 5% per month discharge, we should be OK.

 

[dkoldman]

Thank you. I am planning to leave it over winter not connected to anything.
Even if it had a 5% per month discharge, we should be OK.

As long as you are Happy, you can do that. You can then hang out on the prairie with no worries. If you don't worry... be Happy !!!

 

[happy-THOR]

Oh man! Now I have that song stuck in my head.

 

[dkoldman]

Oh man! Now I have that song stuck in my head.

It should be required listening for all RV owners that feel like they have problems. People need to laugh more, be Happy and not be so uptight. There are some folks when I try to say something to brighten their miserable day, they find some way to misconstrue to bring their miserable hatred out front. I just laugh and ignore. Oh it is like I am sure there is at least one soul wondering what the **** being Happy got to do with not worrying about a disconnected Lithium battery not discharging over the winter.