los2

I have a zippy flightmax 5 cell 5000 mah 30c lipo
please could you guys clarify exactly how it should be stored, i balance charge it to full capacity the following day after a club night.
if i were to store it for say 3-4 weeks do i need to charge it to 3/4 capacity or do i just balance charge it to full capacity?

los2

anyone?

gtsakiris

iTrader: (21)

lipo storage is typically 70-80%, balanced charged of full capacity. Some chargers havea store charge cycle that allows for proper storage. If your doesn't charge till 80% of your Mah or around 8volts. All lipos will lose voltage over time however less rapidly thatn nicd or nimh, therefore all lipos must br maintianed for proper voltage by at least checking every month. Hope that helps.

Duster_360

iTrader: (21)

Current thinking is you'll get better life if you partially charge rather than store fully charged for 3-4 weeks at a time between uses.

If your charger doesn't have a store mode, it may have a discharge mode that lets you set voltage - try 3.7-3.8v/cell. Or you can charge it to rated capacity, then discharge 25% of the rated capacity - that would leave you at 75% - thats the way it was done before chargers started showing up with store mode.

los2

Thanks guys for the help so far.
my core rc charger does not have a discharge function, so i have ordered a 'battery doctor', basically a cell discharger.
so i can discharge my cells to 75%, i know my 5 cell lipo is rated at 18.4 v but it will charge to just over 20v so if i want to discharge it to 3/4 capacity do i need to dischahrge to 17.5v?? which would be 3.5 v per cell?
sorry to keep asking Q's im just having a hell of a job getting my head around the math of it all
Thanks

LST2go

Before I got a charger with storage mode I would just charge to 50 or 75% capacity after running. If Iwas running a 5000 pack i would put back no more than 4000 mah.

Razathorn

iTrader: (2)

The only point to storage charge your lipos is so they don't go below 3 volts a cell and puff. Other than that, there is no reason to do it. On the other end of the spectrum, don't leave them fully charged either! The more you leave your packs sitting with more charge in them the faster they degrade and increase their self discharge rate, which means they will self discharge and puff.

What I do is this: Ignore week to week. After running, they're not fully charged, and they're not near 3 volts. If I have a pack charged, I'll throw it on storage in the garage in the lipo sack and let it drain that night. If I hit cut-off, I bump the pack with full charge current for 10 minutes -- that's more than enough to keep it through the week.

Lots of opinions are out there on storing lipos in the freezer -- I have left my 'ran packs' in freezing temps for a few days with no ill side effects and at least one lipo manufacturer says to store them long term this way if possible. Honestly, I have no fear of letting mine get that cold at all.

My lipo MO is simply to not leave them fully charged or dead week to week. When I miss weeks, I might check the voltage, but they never go anywhere in that period of time.

los2

Thanks guys for the help so far.
my core rc charger does not have a discharge function, so i have ordered a 'battery doctor', basically a cell discharger.
so i can discharge my cells to 75%, i know my 5 cell lipo is rated at 18.4 v but it will charge to just over 20v so if i want to discharge it to 3/4 capacity do i need to dischahrge to 17.5v?? which would be 3.5 v per cell?
sorry to keep asking Q's im just having a hell of a job getting my head around the math of it all
Thanks

TD-Ent

iTrader: (75)

Manufacturers recommend 3.6 or 3.7 volts per cell, so in your case, 18 - 18.5 volts. Make sure they are balanced as well.

encore75

iTrader: (26)

Or, use the suggested amount of 75% of capacity. Since your pack is 5000mah, 75% of that (5000 X 0.75) = 3750mah.

Simple math.

Duster_360

iTrader: (21)

When your 5S is charged, its 21.0v (5 x 4.2). Either use the capacity like it used to be done - if 5000 and want 75% then disch 1000mah from fully charged condition. Or simply store at 3.7 - 3.8v/cell (18.5 -19.0v). Voltage to storage is not linear, so don't just take voltage times 0.75. You will overdischarge a lipo using that logic - for 65% you would be at 2.7v/cell and below minimum cell voltage.

Unless your lipo is an SMC lipo, there's really not set, best guaranteed storage formula. If your lipo came with instructions - read them, sometimes they're nothing but safety precautions, but ocassionally they will address these issues. Follow manufacturers guidelines above anybody else's advice. They know the product best.

armourbl

iTrader: (44)

I use my batteries at least once every couple of days. I've been charging them to full capacity, and storing them that way until my next use. At worst, this has been 5 days max.

I guess I need to start using the storage mode at the end of the day instead. Bummer in that is I need to then account for charge time before I can go play. I kind of like getting home from work and going out for a quick buzz before the sun goes down. If I have to charge them, that won't be possible anymore....

ben

Razathorn

iTrader: (2)

If it's just a quick buzz, charge them to 80% or something. Far better than 100%.