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Electric Stunt => Gettin all AMP'ed up! => Topic started by: Paul Allen on November 16, 2009, 01:38:42 AM

Title: Li Po
Post by: Paul Allen on November 16, 2009, 01:38:42 AM
How long do Lipo's hold their charge?
 Thanks
Paul Allen H^^
Title: Re: Li Po
Post by: Alan Hahn on November 16, 2009, 07:33:58 AM
I have gone at least a week waiting for good weather with a charged up lipo. Actually holding their charge is one of the "pluses" of a Lipo.

That being said, leaving the Lipo fully charged for a "long" time ("long" not being well defined, but maybe starting at a week in length) is considered a form of Lipo abuse! Apparently they tend to age faster. So if I know I won't be flying for a week or more, I'll discharge (slowly) my pack to roughly 1/2 capacity.

For really long periods--like over winter when you aren't going to fly at all, the current "best practice" is to discharge (or charge) to 1/2 capacity and refrigerate (not freeze!) in a sealed plastic bag--trying to keep condensation to a minimum. Then when you are ready to fly again, let them warm up in the bag, and then charge and go fly!

This like I said is considered to be the proper way to treat your lipo. I think there is some science behind it. It is also the reason, I think, that you get your lipos from the distributer at 1/2 capacity.
Title: Re: Li Po
Post by: John Cralley on November 16, 2009, 07:44:13 AM
I just charged a couple of 3S 460 mah batteries that I have had for over a year (bought for a 1/2 A project that never happened) and they seem fine. These batteries were not refrigerated but were in the "storage charge" condition that they had when I bought them (about 50%). I just soldered on the connectors and put them on the charger. I have not checked to see if they still have the 460 mah capacity so I may be being over optimistic.

John
Title: Re: Li Po
Post by: Dennis Adamisin on November 16, 2009, 07:50:33 AM
My GT-A6 Charger (similar to the Accucel-6) has a "Lipo Storage" mode, which discharges back to nominal 3.7V per cell - about 1/2 capacity as Alan noted.

I do not have any spare refrigerator space (the cook would also throw a fit) so I leave them outside in the garage; it does not freeze but it chills out nicely!
Title: Re: Li Po
Post by: Paul Allen on November 16, 2009, 10:00:45 PM
Thanks for the info,just found the LiPo Store Mode on the charger!
Paul Allen
Australia y1
Title: Re: Li Po
Post by: Ron Heckler on November 20, 2009, 11:49:29 AM
Hi Fellas,

I have an original triton charger. When I store my LIPO batteries for the winter, can you tell me how I would discharge them to 1/2 power.  Any help would be appreciated.

Ron
Title: Re: Li Po
Post by: Alan Hahn on November 20, 2009, 02:08:15 PM
The easy way would be to put an undersized prop on the setup and run the lipo down to a safe charge level, and then charge it back up to the 50% level, which as I recall, is about 3.8 V/cell. You don't have to be super precise, anywhere from  3.7V to 4.0 V is just fine.

Main point is to NOT store them fully charged or discharged!
Title: Re: Li Po
Post by: Ron Heckler on November 21, 2009, 02:01:10 PM
Thanks for getting back to me Alan. I appreciate the info.

Ron