LiPo Storage (How Long is Too Long?)
 

I have four 5000mAh, 3-cell LiPo batteries that I've used very sparingly just this season, before deciding that the plane really performed much better with 4-cell batteries, which I have just purchased. I may not find a use for the 3-cell LiPo batteries for a least a year. I just put a storage charge on them with a Cellpro Multi4, and put them away. Question I have is just how long can they be stored, and is there any maintenance that needs to be done?

Thanks in advance for any responses.

RE: LiPo Storage (How Long is Too Long?)
 

I'd give them a storage charge (40% or whatever your charger specifies as a storage charge) and they should be good for, i'd say 1 1/2  years.

RE: LiPo Storage (How Long is Too Long?)
 

I truly depends on the quality of the batteries the higher the quality the longer they'll last

RE: LiPo Storage (How Long is Too Long?)
 

After putting the storage charge on them....Does storing them in the winter in a cold temp help? If it does, I keep them out in the unheated garage for the winter.

RE: LiPo Storage (How Long is Too Long?)
 

I'm not sure how the 1.5 year number was derived. I have batteries that are well over 3 years old and still perform well and also had batteries that took a dump after 6 months. And yes, I store them at 3.85v/cell at 36 degrees. I do not discharge over 80% of capacity. During use they do not go over 110 degrees. There are many variables that effect the longevity of the cells. Usually heat, charge state(if kept fully charged or repeatedly discharged over 80% of capacity) and type of ab/use.

I would check the internal resistance of each cell in the pack, storage charge/discharge them between 3.8-3.85v/cell and store them in a cool place (I store mine at 36 degrees). When you are ready to use the batteries again let them come to room temperature(about 75 degrees) and check for internal resistance again. You can also cycle them once and check IR again. Another way to check is if the cells are holding good voltage under load (generally 3.7v/cell and above is good)

More info here http://www.rcgroups.com/forums/showthread.php?t=1330647

Lots of info in this thread http://www.rcgroups.com/forums/showthread.php?t=1477091