Lipos & Storage

[nerdo5953]

I want to store my lipos for 2 months and wondering about the best way to do it. I read somewhere that lipos shouldn't be (over)discharged for storage! Anyone who can confirm this. Thanks

[ghtracey]

3.7V/cell is the ideal storage voltage.

[Pinecone]

Actually best storage is 50% charge, which is a no-load of 3.8 - 3.85 volts per cell. If you check, you will find taht new lipos come at this charge level.

Some chargers will charge or discharge to this point. FMA CellPro 4S A123 version and ThunderPower 1010C are two that I know of.

[uniquexme]

m using imax b6, i think similar to Estation BC6, it comes with this storage function which is really cool. so just select that and it will take care of it. thanks.

[Pinecone]

The other thing I do just set my timer for less time.

If my normal timer setting is good for 80% out of the pack, I set the timer to Normal Time x 5/8 (50%/80%). So for a normal 7 minute timer setting 7 x 5/8 = about 4 1/2 minutes. Fly and the pack is at about 50%.

[nerdo5953]

Thanks a lot guys!

Terry, do you "fly" with the pack after mentioned calculation to reach 50%?

Another question; what happens if lipos are stored with a full charge?

[Pinecone]

I fly the fully charged pack the reduced time, and it is ready for storage. Before flying again, I recharge.

If you store at full charge they can experience a permanent reduction in capacity.

[Common Sense RC]

As mentioned it is best to store at about 50% charge. However, lipos have a very low self discharge rate. I have left lipos fully charged for weeks then flown them with no noticable effects. I think it is just best for their long term health to follow the 50% rule.

Ryan Lefevre
www.CommonSenseRC.com (http://www.CommonSenseRC.com)
The Go To Guys For Electric Power

[Finless]

However storing a fully charged lipo for a long period actually hurts them. They loose capacity. I don't mean leakage I mean they loose capacity. This is why it is recommended to store at 50% because the damage loss is way less than fully charged. Also heat while stored increases the rate at which they loose capacity.

Helifreak user HFG taught me this with a fact/data sheet and later I confirmed it with a cell manufacturer so it is not BS.

Bob

[DebianDog]

As mentioned it is best to store at about 50% charge. However, lipos have a very low self discharge rate. I have left lipos fully charged for weeks then flown them with no noticeable effects. I think it is just best for their long term health to follow the 50% rule.


Yep that is the general consensus. If they have stayed charged for a while I will also try and put a 1 minute hover on them then recharge them real quick. Get the electrons used to moving around again. Your pack will be "hot as a firecracker" (flying wise not temperature) after that too.

[zagiman]

Do you then store them in a cool place like your fridgerator (not the freezer part)? If so, do you still keep them in a bunker type device?

[Blue Note]

Just out of curiosity, do the same rules apply when storing Li-Ion batteries?