dadzilla-5

Well , the title saya it all - can I store my lipo packs charged, or is it better to run them down a bit? Thanks for your input.
zilla

Red Scholefield

My Feedback: (9)

The manufacturers recommend they not be stored fully charged. As I recall they recommend something in the range of 40-60 % charged.

ridietz

My Feedback: (7)

After some failures or LiPo Packs, I was able to get this from [email protected] or Thunder Power packs. Wish I had seen it before I had ruined a couple of packs at $80 each. Dated 6/30/04

Hello again Dick,

Actually, just yesterday we finalized the latest update in regards to storage of our packs:

Short term pack storage:

- Packs which are to be stored for up to 1 week until the next flying session can be safely left fully charged

- Packs which are to be stored up to 4 weeks should be discharged to 60% of capacity (ie: 1200-1300 mAh remaining for a 2100 mAh pack)

Long term pack storage:

- Packs which are to be stored long than 4 weeks should be discharged to 50% of capacity (ie: 1000-1100 mAh remaining for a 2100 mAh pack).

- For optimum long term storage, packs which are left 1/2 charged for 4-6 weeks should be charged to full, then discharged to back to 50% and stored for another 4-6 weeks.

Thank you and enjoy,

Jason @ Thunder Power

I am now using KoKam from FMADirect.

Dick Dietz, AMA87885

Greg Covey

I store all my Lithium packs charged.

This way, I'm ready to fly when the weather is good...up to a month later.

I figure that the technology will outdate my packs anyway before they go bad from storage issues.

ridietz

My Feedback: (7)

Any other experience out there with packs that are stored for months. I can't fly for a few months in the winter and don't want any more failures blamed on long term storage of fully charged packs.

Dick

IA-Flyer

[link=http://www.batteryuniversity.com/partone-19.htm]How to store batteries[/link]

Red Scholefield

My Feedback: (9)

Excellent writeup - I highly recommend it.[sm=thumbup.gif]

Greg Covey

Unfortunately, it doesn't address Lithium Polymer cells or what we call "Lipos" in the thread topic.

Edited Note: It appears Lithium Polymer is a subset of Lithium Ion so the same storage properies are likely.

Peter Khor

My Feedback: (4)

Dick, just imho ... I don't think a 6/30/04 pack, runined (say today) in under 4 months would be due to storing at full charge (say you used it only 4 times ... 1 month storage in between). I've had KoKam, TP, Tanic, Etec's with >1yr on them, some with ~1month or more of full-charge storage, and then use - never had a problem with them due to storage (other problems like crashing, yes ) - you might consider some other issues. (also, iirc there was a batch of Gen2's that had some problems initially?)

fwiw, KoKam's are LiPo's too, and will be affected by the full-charge storage problem. (there is no mention of how to store LiPo's in the tech doc https://www.fmadirect.com/support_docs/item_1115.pdf although iirc Fred had mentioned it before in passing on some thread).

ridietz

My Feedback: (7)

I'll be preparing to store some LiPo's for a few months this winter, and will do so at reduced voltage. An alternative is to run some bench cycles during this period of downtime. I'll be building new planes and have tests to run on esc's etc.

Thanks for all the input! I am much smarter on LiPo's as a result of all the good replies.

Dick

Whistler71

I have a small fridge that I can dedicate to lipo batteries, should I store them even when fully charged in this said fridge or just store them in there at the 3.8V per cell storage voltage if not used for more than a week or two...?