LiFePO4 battery storage

[RT-NY]

I took my fully charged LiFePO4 battery out of my van and will keep it inside my house for the winter. Will it do any harm to sit unused fully charged for three months? The manufacturer recommends leaving it half-charged if it will be unused for more than a month or two, but I would like to keep it fully charged to use to run my computer in case of a power outage. I do not currently have an appropriate charger in the house to keep it plugged it (I have a charger built into the van, of course, but not a stand-alone charger in the the house).

[Rlum]

Originally Posted by RT-NY

I took my fully charged LiFePO4 battery out of my van and will keep it inside my house for the winter. Will it do any harm to sit unused fully charged for three months? The manufacturer recommends leaving it half-charged if it will be unused for more than a month or two, but I would like to keep it fully charged to use to run my computer in case of a power outage. I do not currently have an appropriate charger in the house to keep it plugged it (I have a charger built into the van, of course, but not a stand-alone charger in the the house).

I have read, LiFePo4 like to be around 30-70 percent charged. Not fully charged or discharged. You can buy an inexpensive lithium charger from Amazon for 30-40 dollars. I purchased one a couple of years back when I was increasing my battery bank and needed to balance the cells before installing. It was only 4-5 amps/hr but it worked. It was the only one available at that time. The 20am/hr option had a 30 plus day wait for delivery.

[Deano]

Lifepo4 batteries don't like a float charge. So, if you get a charger be sure it is specified for that chemistry.
I have a Lifepo4 in my car that is only driven occasionally, and even though I have a compatible charger I have it on a timer for 1 hour a day. This keeps the battery at full charge in spite of the parasitic discharge.
In your situation, 3 months probably would be OK. However, I would check the SOC periodically

[RT-NY]

Originally Posted by Deano

Lifepo4 batteries don't like a float charge. So, if you get a charger be sure it is specified for that chemistry.
I have a Lifepo4 in my car that is only driven occasionally, and even though I have a compatible charger I have it on a timer for 1 hour a day. This keeps the battery at full charge in spite of the parasitic discharge.
In your situation, 3 months probably would be OK. However, I would check the SOC periodically

That makes sense. I wonder if home backup power systems that use lithium batteries (instead of a generator) do something similar. I would think that they need to be kept near a full charge and then given a periodic short charging to keep them there. Is anyone familiar with these kind of things (maybe like Tesla's "powerwall"?).

[JonMN]

With all the electronics in the Class B coach, just wondering how many things need to be reset if you take out the coach battery. I'm thinking of the Vegatouch, Truma, Xantrex I/C, etc--do they typically keep their settings? I've changed a lot of batteries, but never an RV coach battery!

[booster]

Originally Posted by JonMN

With all the electronics in the Class B coach, just wondering how many things need to be reset if you take out the coach battery. I'm thinking of the Vegatouch, Truma, Xantrex I/C, etc--do they typically keep their settings? I've changed a lot of batteries, but never an RV coach battery!

One thing to remember is if you have solar, you need to disconnect the panels from the controller if you are going to have the coach battery out of the van or totally disconnected.


There is the option of having the panels covered in some way to keep the sun off them or storing it inside so no sun.


No battery reference to the controller can lead to a high voltage spike in the sun.

[RT-NY]

Originally Posted by JonMN

With all the electronics in the Class B coach, just wondering how many things need to be reset if you take out the coach battery. I'm thinking of the Vegatouch, Truma, Xantrex I/C, etc--do they typically keep their settings? I've changed a lot of batteries, but never an RV coach battery!

My van is an 1999 Roadtrek 170 so the electronics are very simple. Nothing needs to be reset if I take out the coach battery (and I do not have solar). But the van does need the coach battery in place if it is to be driven and to run the generator. When I did my upgrade to lithium, I left the SLA battery in place and put in a manual switch to the lithium system so both exist independently, isolated from one another. The only complication is the charger settings, but for my setup it is very easy to manage!

[Deano]

Originally Posted by RT-NY

That makes sense. I wonder if home backup power systems that use lithium batteries (instead of a generator) do something similar. I would think that they need to be kept near a full charge and then given a periodic short charging to keep them there. Is anyone familiar with these kind of things (maybe like Tesla's "powerwall"?).

Interesting you ask about Tesla Power Wall.
I have one. Now I don't claim to understand everything about how it is supposed to function, in spite of every thing I have read about it.
However, I check the solar and grid output almost daily. While the battery is programed to be at 100%, on occasion it will show 96,97 or 98%. The next time I check it is back to 100%.
So, I'm thinking you may be correct thinking it either has self discharged or was programmed to shed some capacity to allow a brief recharge.

[RT-NY]

Originally Posted by Deano

it either has self discharged or was programmed to shed some capacity to allow a brief recharge.

This is what I am wondering about! As I understand it, the self discharge rate of lithium batteries is quite low. So, in theory, a full battery can sit unused for a very long time and still maintain a charge. But the impression I get is that sitting unused actually does damage to the battery. What I would like to understand is what causes that damage?

[JML]

I have a BattleBorn GC270 LiPo. I keep it in the RV with the lowest temp registered at 12 F. I do not remove the negative cable but have all the red keys turned off and the battery isolated with no load on it. It is at 100% capacity with no load for the winter, though I will on occasion go into the van and turn on power if I'm working on something. Here is what the manual states for storage: How to Properly Store Batteries
We recommend bringing the Battle Born batteries to a 100% state of charge. Then, disconnect the battery from any loads by removing the negative cable from one battery. On average, the batteries lose approximately 2-3% capacity per month. This is subject to increasing if stored in extreme environmental conditions.

I have had no problems with this battery or the Stark brand 100 AmpHr LiPo I replaced this with. The BMS prevents charging in freezing temps if I happened to forget and leave it connected to shore power or if I run the engine or generator in freezing temps.