yorcram

I think I read someplace that lipo's should be stored at 30% below full charge for long term storage. So, I was wondering how long to leave them fully charged for?. I fly infrequently so I leave the batteries charged for the times I am able to get out. It is normal for me to go weeks and sometimes months before the weather and work schedule line up.

Cheers,
Marc

Matt Kirsch

Unfortunately, there's no hard-and-fast rule for this. As you can probably tell by the lack of responses, the community in general is going, "Ummmmmmmmmmmmmm..." I am too..

I believe many are like me. They charge up the packs with grandiose plans of going flying, then something gets in the way and the packs sit fully charged for months on end.

Really, the jury is still out on exactly how these battery packs should be stored long term, because a generation of cells isn't out long enough for long-term trials before the next generation of cells comes along and renders it obsolete (meaning all the buzz is about the new cells, not that the old cells are useless and should be discarded). Hopefully with these 20C rated cells, things will slow down and we'll get some solid answers.

I can tell you that I've left packs fully charged over the winter and have not seen any detrimental effects. Take it as it is, though: Anecdotal evidence that doesn't necessarily reflect scientific fact.

Unbalanced prop

Man ain't that the truth. I store mine at 40% to 50% charge during the winter, but I can't prove if this is good or bad or does absolutely nothing for them. But since the packs come to me at about a 50% charge, that is where I store them at. That being said, I have had packs (old Etecs) sit for months after a full charge and they performed just fine when I finally used them.

Doug

yorcram

Thanks for the comments,
At least I now know people have left their packs fully charged for months, so I won't worry too much about doing the same.

Cheers,

nadt770

Used to work as a Tech in the LiPo industry. In the lab we stored them at both 30% and 100% for data collection purposes. We never saw much difference as far as swelling or discharge. However we only collected data for several months at a time. We shipped them at 30%

John

floridawen

Sometimes it's not possible to charge the LiPo the "night before" you plan on flying. Sometimes I charge them on a Friday night and it rains that entire weekend....... my question is, will that charged LiPo have 100% CHARGE in it a week later or should I "refresh" them again on the charger ?? How LONG will a LiPo keep close to 100% of it's charge ??
Thanks..........

Nitro Blast

I've attended the AMA Expo for a few years, and each time I have sat through the Thunder Power LIPO lecture. Good stuff.

Basically its a performance item. Storing them at around 50% is the best for long term life, but storing them at 100% only causes a 1~2% drop in full discharge performance. The key word is FULL DISCHARGE. Guess what, you dont fully discharge our batteries do you? Usually not. Most guys dont even take them to the low voltage cutout. So.... continually peaking the battery and storage although has a measurable reduction in performance, that measurement is exceptionally low.

I often charge on Friday, for a weekend flight. I've brought batteries home that were not used, only to use them again in 2, 3 or 4 weeks later. I've put these batteries on the charger, only to see stuff like 5 maH put back in. Its very nominal indeed.

How long can a charged pack sit? MONTHS! MANY MONTHS!
If you are fussy, store 1/2 charged. If you are like me, dont sweat it and the battery still works for its designated 2~3 years.

I used to really monitor it, now honestly, I dont even care. I charge them, fly them, then take them home. I still use batteries that have 2005 written on them! (its awesome to take an old 3 cell battery, and power your TX with it, it lasts for an exceptionally long time on that old Lipo that would give you nominal performance on a airplane).