Author Topic: Lipo pack weekly storage state of charge (Read 514 times)

Dennis Toth · « **on:** July 28, 2019, 06:55:55 AM »

Guys,
I have been flying electric for five or six years with various size lipo packs. One thing I experienced has been puffing of the pack. I researched this and found that my practice of fully charging me packs after I return home from flying and letting them stay in that state of charge over the week or more was the main cause of the problem. I am a bit lazy so once I found this out now I just leave them uncharged at whatever the pack is at after a flying session (maybe 20%). Since I also fly several OTS ship that are IC powered sometimes the packs will sit for several weeks without being used. So far the packs (Zippy Compact) have held up well without any puffing.

Quesion for the group - is this a reasonable practice for reasonable pack life (particularly for Thunder Power's)?

Best, DennisT

Jim Mynes · « **Reply #1 on:** July 28, 2019, 08:22:41 AM »

The general consensus is that LiPo batteries should be at roughly 50% state of charge for storage. That’s 3.85 volts per cell.
Most quality chargers have a “Storage” option which will charge or discharge the pack to something near 3.85v/cell. The first charger I owned did not have that feature, and I ruined some batteries before I smartened up.
Leaving your batteries at 20% for storage is way better than 100%.

William DeMauro · « **Reply #2 on:** July 28, 2019, 09:09:29 AM »

To add to what Jim said; Since you were charging them when you returned from your flying session anyway just set your charger for storage mode and bring them all back up to 50% and leave them there. They will charge that much faster on the day you actually fly. Any unflown packs should be discharged down to 50% also as soon as possible. I have found that my packs preform better and last longer if they are not kept at full charge any longer than necessary. If you have a good charge/discharge setup this is usually pretty easy.

Dennis Adamisin · « **Reply #3 on:** July 28, 2019, 09:39:14 AM »

I'll echo what Jim M said.

ASSUMING you are not discharging to a extremely low level (3.0V or so), storing in a post-flight mode (20%-25%) should be just fine. For unused packs, discharging them to the 50% state afforded by most chargers should also do fine.

As an aside, I Balance Charge all the packs I expect to use THAT DAY at a 1C rate. When I am checking power usage after a flying session, I will recharge (also Balance cycle) to count the mah replenishment & calculate usage percentage, then discharge back to storage mode. This has worked especially well on a set of nine Arrowind 4Sx2200's that I have been using on almost everything over the past 6 years in service.

Author Topic: Lipo pack weekly storage state of charge (Read 514 times)

Dennis Toth

Lipo pack weekly storage state of charge

Jim Mynes

Re: Lipo pack weekly storage state of charge

William DeMauro

Re: Lipo pack weekly storage state of charge

Dennis Adamisin

Re: Lipo pack weekly storage state of charge