Lipos not used for a bit

[Jnunu1]

Hi

I havnt had chance to use my lipos since May but I didnt sort out doing the "storage" mode thing with them.

Will they be ok to charge up and use - or will i burn to death?

[sosidge]

I was in the same situation (having left the cells un-store-moded for 6 months) and I survived.

But I did check the cell voltages before charging, and I did use the balance lead.

[jim76]

if they are still above 6v then they should be ok, but i'd defo watch them while they have the first charge in case they swell at all

[Big G]

I got given 2 packs of lipo. no idea how long they had been sat, but both work really well

[Jnunu1]

Originally Posted by sosidge

I was in the same situation (having left the cells un-store-moded for 6 months) and I survived.

But I did check the cell voltages before charging, and I did use the balance lead.

What sort of thing were you looking for on the voltages - 6V like Jim76?

Ta

[sosidge]

Originally Posted by Jnunu1

What sort of thing were you looking for on the voltages - 6V like Jim76?

Ta

Do the cells independently (ie measure through the balance port).

3V per cell would be a bare minimum. I'd be looking for something a lot closer to the nominal 3.7V or higher.

Mine had been left fully charged for over 6 months and they were still over 4V per cell. Balance charged evenly first time and no noticeable performance issues since. Intellect 5000 30C pack for reference.

[Jnunu1]

Hmm - tried to have a look at the lipos tonight.

Plugged them into my UDC30 on a balance charge and just got an alarm and "low voltage" warning on the battery check.

I cant seem to get the charger to do a reading on the cells without it "charging" - but I guess they must be below "safe" i.e 3v.

Any ideas anyone - or is it new lipos and a lesson learnt?!

[liam]

i get the low voltage warning if my 12v battery supply goes below 10v input

could be that unless your plugged into a mains supply

[Jnunu1]

Originally Posted by liam

i get the low voltage warning if my 12v battery supply goes below 10v input

could be that unless your plugged into a mains supply

Hi - nice thought but am into mains!

[blue_pinky]

Low voltage alarm is a bad sign! But if you can get a voltmeter reading off the cells as a second opinion that'll tell you for sure.

I've heard of people recovering cells from below that with some "special" charging skills, but certainly not recommended practice, and they were never as good after they'd been recovered.

Probably not worth the risk?!?!?

[fidspeed]

as previous posts try to check cell voltages individually.
I have had success in the past recovering lipos by using a nicad charge setting for a while watching voltages rise to a point where a lipo charge can work . THIS IS NOT GUARANTEED OR RECOMMENDED IF YOU DONT KNOW WHAT YOU ARE DOING

but i have used it in the past and it has worked for me

(donning tin helmet and awaiting bombardment from experts

Dave

[Mouton]

I take it they where empty in May? Otherwise they should still be full. A couple of months ago I found our old heli and its batteri had been fully charged and tucked away with the chopper some two years ago. It was still about 85 % charged.

Use a LiPo-sack, and charge at 1 C (while you stay in the room). As you say, any loss has already occured so you only risk loosing a couple of minutes more if they do not take charge.

[Jnunu1]

Time to buy some more lipos - too chicken (and attached to my face) to give it a go.

Thanks for all help. Lesson learned.

[rizka]

i have also recovered a bad lipo which i over run accidentally ,i charged it without the balance lead connected for 5 minutes and that gave me enough voltage to get it going again without low voltage alarms ,if your worried put your battery in a biscuit tin while charging and make sure your near an open door ,if you get swelling or smoke put it outside they dont go off like a rocket unless you put a nail through them ..check youtube for exploding lipos ...nOt really an explosion more like a smokey end hehe