diy solar

diy solar

How much better is it to store at 40-70%/How much damage by storing at 100%

MasnPip

New Member
Joined
May 13, 2021
Messages
30
I understand that it is best to store lifepo4 batteries at something less than 100% soc. However, I can’t find any information as to how much better that is for the batteries? Meaning, how much life will I cut from the batteries if I store them at 100% instead of storing them at a lower soc. The reason I ask is that I’m making some Eve packs that will primarily be used as backup for power outages. That happens maybe 1-2x/yr. If I store them at 50%, I’m kinda screwing myself out of half of the usefulness of the battery at the very time I need it. Since these are only to be used rarely, would I really be losing much long term battery life if I store them at 100%?
 
It depends heavily on temps. If these are stored in climate controlled area around 25°C, deterioration will be low.

I have 9 Eve cells that I fully balanced back in January, and they've been sitting ever since in my comfy office. I have little concern that they will experience significant deterioration.

Even storing at something like 80-90% can make a pretty big difference. This can be accomplished by charging to around 3.35V/cell.

For your stated application, AGM is really the best choice. Even if you use 80% of the AGM capacity 1-2X/year, you'll get many years of service, and they love being stored at 100%.

If these cells will experience elevated temperatures, count on significant deterioration.
 
100% is significantly worse than 70% or lower

 
It depends heavily on temps. If these are stored in climate controlled area around 25°C, deterioration will be low.

I have 9 Eve cells that I fully balanced back in January, and they've been sitting ever since in my comfy office. I have little concern that they will experience significant deterioration.

Even storing at something like 80-90% can make a pretty big difference. This can be accomplished by charging to around 3.35V/cell.

For your stated application, AGM is really the best choice. Even if you use 80% of the AGM capacity 1-2X/year, you'll get many years of service, and they love being stored at 100%.

If these cells will experience elevated temperatures, count on significant deterioration.
Thanks! I can store them in my basement, which is cool and dry at all times. I looked into AGM, but have decided to go w lithium so that they can be more portable for the occasions when I want to take them camping or whatever. Great idea to store at 80-90%. That sounds like a good compromise.
 
100% is significantly worse than 70% or lower


Post below the one you linked indicates 5% degradation @ 100% @ 25°C illustrating my point that temperature plays a big role.
 
100% is significantly worse than 70% or lower

Thanks! I had not seen this thread when I searched!
 
Post below the one you linked indicates 5% degradation @ 100% @ 25°C illustrating my point that temperature plays a big role.
I am really surprised by the impact of temps. Esp important since many of us have these things crammed into a hot rv
 
Back
Top