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[gerard]

Hi
Can anyone advise me as to how long you can leave a fully charged lipo battery without using it and having to discharge it
Thanks
Gerard

[Peter Fitness]

I have had no experience of LiPo batteries myself, but there is some good information on their care here-


http://www.hobbywarehouse.com.au/articles/lipo-battery-care-maintenance.html


http://www.icharger.co.nz/articles/ArticleId/6/Introduction-To-Lipo-Batteries.aspx


You need to scroll down to near the end of the second site to find a section on battery storage.
I hope this helps.




Peter

[gerard]

Thanks Peter,
Will look that up and give it a good read.
Gerard

[grendel]

from memory lipo's should be at around 40% charge for long term storage.
Grendel

[nick_75au]

3.7 volts per cell is storage voltage, more than a few days at full voltage is not ideal.


i use them, charge at the end of the day to storage. The night before fully charge ready for the next day

[gerard]

thank you both for the info Grendel and Nick
Gerard

[grasshopper]

I left my model truck 2s (7.4v) 5000mAh cells with a full charge for the whole winter, from October to last week and there was no loss of charge, stuck them in my truck and raced them - no problem at all.


Some of the other chaps in the club did the 40% storage charge thing then charged them at 1c rate and blew a couple of cells in their packs, some came to find their packs had one cell that had lost their charge and none of them are using 'cheap cells'


If you do go the 40% way of storing them  trickle/ balance charge the packs the first time if they have been left for any extended period, that should reduce the chance of swelling a pack and blowing them.

[nick_75au]

Interesting, the difference could be the heat here, i had left a fully charged one for a few months ant it became puffy, an identical pack at storage was fine.


your last comment IMO should be done for every charge  

[grendel]

I go here for my information - http://batteryuniversity.com/learn/article/how_to_prolong_lithium_based_batteries
these people are very informative and quote good scientific statistics for all their work.
Grendel

[grasshopper]

I started out balance charging each of my packs every time, I check them with a LiPo meter every time I insert or remove them from my truck but they never drifted out by more than a few millivolts, I would only balance charge them every time one of them drifted out by half a volt or more.


Some of my packs are now over four years old and still perform well in races, however I never charge them at higher than their C rating, sometimes at less than that if I am not in a hurry, some of the newer LiPo batteries can be charged at higher than Their C rating but personally not something I would risk very often.


Science is a wonderful thing but sometimes it's not always transferable into real life,  if you have no other information then use it by all means but it isn't always the definitive answer as the scientists don't always allow for abuse by we modellers!