Question for Raf re LiPo Charging

[chansen1953]

hi Raf, I thought this might be up your alley !!

I have been using an Imax B6 charger for th epast 12 months and it has been fine till the last few weeks. all of a sudden I find that some of my batts let me down ofter only a short flight.. and when I check, it is always cell-1 that is way down on voltage..
I then have to run it up in the NiMH charge till it gets to 3v, before I can give it a balance charge.
I checked all of my batteries, 2 of the 6000mah Nano-techs, which have only 2-3 re-charge cycles on them, have got very low cell-1's..
my fairly new Lightmax 3000 6S cells also show the same -- cell-1 is low.
I checked all of my batteries, including 3-4 I have put aside as "no good ".. same story.. cell-1 has gone very low.. till battery is unusable..

I can only find one common thread... they are all being charged on the iMax B6..

often I leave it running whilst I amin the other room, and leave it plugged in after the alarm has gone off (chagre finished that is !) .. so maybe the charger has a faulty circuit and is dischargingcell-1 thru the balance leads.. after the charge has finished..

any way to check this ??

I have ordered an iCharger 1010B+ because its all I can afford right now, after losing 4-5 batteries recently it has cost me dearly..

I will be recording the cell voltages of every battery after charging and store all these voltages in a Spreadsheet where I can grapg each cell and determine if any are slowly dying or if there is any bad trend arising.. ( I know there is a celllog device that can do this for me, but unfortunately I bought the non-log versions.. didn't think it was an important feature till now !!)

so Raf, is it possible that the charger is ruining my batts, or just bad luck that all of them have cell-1 faults !!

[redbird300]

Doesn’t sound like bad luck at all to me, it must be the charger indeed. You could measure the voltage over cell 1 with a voltmeter while charging to know for sure, but it is so highly probable that I wouldn’t even bother. Good chargers indicate all voltage levels on each cell while charging, so you shouldn't encounter this problem anymore in the future.

Many newer iChargers come with the “LogView” software which allows you to record the charge/discharge data automatically on a connected PC, the 1010B+ has it, but not the 1010B for example. I never used the feature myself, but it’s all in the manual, which you can download from the Junsi website.
http://www.jun-si.com/EnProductShow.asp?ID=93

Good luck, and sorry to hear about the packs.

[chansen1953]

thanks Raf,
I didn't realise the 1010b+ does have the logging.. so thats a good advantage...
I did read the manual, but it does not actually indicate exactly what data can be saved.
I would like to charge a battery up, then when finished , save the 6 cell voltages out to my pc to keep track of any chages over time.. anyway.. already ordered it, so hopefully I can do that or grep the info out of the data somehow..
thanks again for you help..