how many MAH does a lipo lose in 2 weeks

[blueb8llz]

does anybody have a estimate figure to how much MAH a lipo loses in 2 weeks? reason for asking is because sometimes i take a break from RC and ive had breaks as long as a year. so im just trying to figure if i was to take a year break, how often should i charge up my lipos again. im thinking i should first charge it up 50%, then every month give it another 50% charge. is this the correct way. i dont want to give it a 50% charge if it only like like 1000 mah in that month, which would give my lipo over 50% charge storing.
if it matters, i have a neu energy 5000 mah lipo.

[bl-is-future]

to store a lipo discharge to half the capacity and periodically check it for any voltage loss. Would hurt to check every week at first so you know an average the pack is losing then you can judge for future checks after that.

[blueb8llz]

not sure if im reading this correct, but when i plug the balancer and power into the lipo, it reads 7.839 volts. but i only charged it up 50% like 2-3 weeks ago. and my lipo is only a 7.2 volt. at this rate, it seems like i can wait up to like 5-6 months before i charge it up again.... is this right? it can go down to about 3.3v per cell i have a 2s so thats 6.6v.

[DRIFT_BUGGY]

Originally Posted by bl-is-future

to store a lipo discharge to half the capacity and periodically check it for any voltage loss. Would hurt to check every week at first so you know an average the pack is losing then you can judge for future checks after that.

Why only 50% charge?

[blueb8llz]

there has been studies that when storing lipos for a long time, 50% charged had best results. kept its voltage and conditon and so forth, didnt really read the whole thing, just read the most important part...which is 50 %..some people say even 40%.
wierd, i would think fully charged lipos would be best results..but nope.

[DRIFT_BUGGY]

But is 2 weeks really a long time?

[bl-is-future]

2 weeks should be ok but a month i would check them. Really just make sure that your cells dont go below 3.0v per cell (i do 3.2v per cell to be safe)

I was told I would be out of teh country for work 3 weeks - before I went, I ran as many of my lipos as possible and charged them to 50%. The ones I didn't run I discharged and then charged to 50%.

I was gone almost 3months and when I got back all of them had puffed a cell.
I hear storing them at 100% is bad for longevity, but I don't think much of the 50% business either. I'm using 80% and checking them at 1month if I don't think they'll get used. Haven't seen any probs. TCS function on my 0610i charger makes this real easy - just tell it what percent you want and it does the rest.

Def do some kind of maintenance on them - a year and they will be overdischarged.

[blueb8llz]

imma do a test with my lipos. from hearing , it seems that every lipo loses voltage differently. i hope my lipos go 6 months ahhaha. but then i would need to write it down on a calender saying..."charge lipos" on the month cus 6 months....thats a long time i may forget hehe.
i will run the lipo down to lvc, see what the voltage reads, (that number will tell me the voltage my lipo should not go below when its sitting) then charge up 2500 mah , see what the voltage reads,. then thats the number where i should charge my lipo voltage at when its time to charge. again. its prolly gonna be 7.4 volts...cus 6.4 is lvc and 8.4 is fully charged...so halfway between those two is 7.4.

[Serum]

Lipo's don't loose their capacity.

[Sammus]

I've read that lithium polymer and ion chemistries are best stored at about 40-50% charge and have a negligible capacity loss without cycling or anything.

There's some useful information here.

[Larrydino]

i have maxamps batteries...they loose about 100mah in 2 weeks

[Arct1k]

Originally Posted by Serum

Lipo's don't loose their capacity.

Entropy would generally disagree with this... I believe there are charts out there of lipo battery decay

[blueb8llz]

so i did my test. do i have the right idea here? when my 2s 5k lipos are ran down to lvc and i plug it into my charger it reads just about 7 volts. so i charge it up 50% which is 2500 mah, the voltage reads 7.93.
so basically what imma do is occasionally check my lipos when storing for long period, when it drains down to 7 volts, then i know thats the same as when its drained to lvc. ill go plug it into the charger till it hits 7.93 volts, then i know thats close to charging it at 50% again.
now, i just needa see how long it takes for my lipos to actually drain down to 7 volts from 50% full charge. im not gonna do that anytime soon cus im still having a blast. maybe in winter is when ill do the real test.
do i have the right idea here guys??

[maxair45]

Is there any way to check the volts with out a volt meter?