Hi guys! While testing the litchi app, i noticed that one of my batteries was giving a voltage deviation warning on cell 1. Since it was on it's 40th cycle, i did the discharging to 8% and recharging. Today, when i looked at the battery, the battery live had dropped from 98% to 91%, and there is a noticeable difference of 0.1V between cell 1 and the other cells on the go app. I'm a bit worried about this. Is my battery dying? Is it safe to use? Should i contact dji about this? Am i being paranoid? Any advice would be much appreciated.
Im uploading the healthydrones and dji go app screenshots, just in case they help.
Thank you very much!

I have used hundreds of Lipos over the years and I have retired a few dozen.

I always retire a Lipo that will not balance the cels within 0.1v, it is normal to be off by 0.03 or less.

So unless running the Lipo through a few cycles down to 30% and then back to full charge does not get the cells within 0.05 or better I would retire it.

I usually get 500-800 cycles out of a Lipo. And I make a point of never letting it fall below 20%, usually 30%. I don't quite understand the DJI 8% discharge, it is contrary to what I know about Lipos.

One good practice to make Lipos last longer is to break them in slow. First 5-10 flights never go full power and only discharge down to 50%. I always do this and most of my Lipos live long lives. But every once in a while you get one that goes bad early. It is much cheaper to retire them that loose an aircraft.

Westside Osprey Posted at 2015-10-27 21:53
I have used hundreds of Lipos over the years and I have retired a few dozen.

I always retire a Lipo ...

Thank you for your input. I'm in the process of discharging the battery now, hopefully it'll get rescued. The main thing for me is that its only been 41 charge cycles... That does sound a bit meager, for the amount of money they cost. But i suppose that, as you said, every now and again, there is a weak battery...

Westside Osprey Posted at 2015-10-27 21:53
I have used hundreds of Lipos over the years and I have retired a few dozen.

I always retire a Lipo ...

Ok, so I've been charging and recharging, and it looks like the battery is somewhat improved. After two cycles, the difference is gone from 0.1V to 0.05. I guess I'll run a couple more cycles on the battery, and then I'll be really carefull with it, check everytime pre- and post-flight how it is behaving.
Another thing that I noticed is that, as the battery discharges, the difference improves, i.e. at 100% there's a 0.05V difference, while at 60% it might be only 0.02V. Any thoughts on that? Is that normal?
Perhaps it might be a good idea for DJI to give some "when is your battery dying" guidelines.... would that be possible?

Up to 0.03v is perfectly normal and unto 0.05 is acceptable, beyond 0.05v you need to keep an eye on it and balance.

Make sure you not stopping the charge before its completes as the balancing happens at the end of the cycle.

Mad_Angler1 Posted at 2015-10-29 07:43
Up to 0.03v is perfectly normal and unto 0.05 is acceptable, beyond 0.05v you need to keep an eye on ...

I've been reading about balancing, but I'm not sure how to do that on the battery. IIs there any way to force it? Any tools, or protocols?

Thanks!

no it balanced at the end of the charge cycle so just leave it until the lights go out and it will do no harm to leave it another 20 minutes after to for it to settle.