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6s battery not balancing.

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Old 08-10-2015, 05:52 AM
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Talking 6s battery not balancing.

hello all,
i have a 6s battery, admiral brand from motionrc, 5000 mAh and 50c. when i balance charge it the charger never actually says battery full, it simply balance charges for almost 150 minutes and then says, "connection error". When I put a meter on it, all of the cells 1-5 read between 98-99%. get to the 6th cell and it shows 82%. after flying an electric ducted fan and re-checking the cells, all of the cells are between 45-55% accept for the 6th cell which showed 12%. my question is, is the charger charging all cells equally, and then not finishing the 6th cell so not to overcharge the others? second question, is if I bought a balancer and just let it to its thing would that remedy the problem? and the third question is should I call Motion RC and see about replacing the pack? it is essentially brand new. I bought two of these packs, and the other one is perfect, balances nice, and shows near equal percentages on each cell after charging and after flying. thanks for any input i am kind of new to all of this LiPo stuff and just trying to figure out what to do with this battery.
-Steve E
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Old 08-10-2015, 01:33 PM
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I'd see about getting a replacement for the one LiPo acting weird, if the other pack charges fine. The other LiPo 6S takes a full balancing charge, right? The cells should all be within .01v of 4.2v at the end of a balance charge.

Also, do you have some sort of Low Voltage Alarm on you model? LiPo cells shouldn't be drained past 3v per cell.
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Old 08-10-2015, 05:30 PM
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That sounds like a bad cell. If the pack is under warranty they should be able to replace it for you. Each Company has their own terms on these things so I would call them and ask.
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Old 08-10-2015, 09:17 PM
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thanks guys for the input. i called motion rc and the technician there said that the percentage "checkers" can sometimes be a little off, especially on the 6th cell. he told me to try and do another balance charge on it and then check it with a checker that displays in volts and call back with the figures. so i will do just that and see what happens. he did say if it turns out it is a bad cell they will definitely replace the pack. thanks again

oh and to rusty, yes the other 6s pack i bought charges perfectly cells always match right up., i also am not sure if i have a low voltage alarm or not, is this something that would be built in to the esc or is this an additional item I should look into incorporating into the model ?
-steve e
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Old 08-11-2015, 07:16 AM
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As an example...Western Robotics Spectrum Lipo Battery Monitor or a cheap alarm/voltage checker that I use to check my LiPo packs individual cell voltages after use... Lipo-Battery-Tester-Low-Voltage-Buzzer-Alarm
Some people use them for an audible alarm to let them know to "bring it in" before LiPo cells drop to an unsafe level.
Video of the low budget battery tester/alarm that can be found everywhere ...
https://www.youtube.com/watch?v=JryMOh2Ek7A

Last edited by RustyUs; 08-11-2015 at 07:31 AM.
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Old 03-06-2018, 11:51 AM
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I was mad last night when I discovered that another 6 month old 5000 6s Admiral battery had once again died (one cell below 3v) over the winter months while being stored in an ammo box in my office at storage charge. This identical thing happened last year. Last year I called MotionRC they basically told me to suck it up since they didn't know how I may have abused the battery. Well, like I said in my review from last night (not yet posted), I don't abuse the batteries. I time my flights so the batteries have a remaining charge between 20%-30%. I can't remember the last time I flew a battery below the ESC LVC.

So last night I cut off the EC5 and tossed the battery which was picked up in the garbage this morning. This morning I also received an email from MRC which says: Sorry for your bad experience, give us a call. I called MRC and the rep tells me too bad I didn't take a picture and if I had been a mind reader and had taken a picture I would have received a replacement.

This is outright BS! You didn't replace the 5000 6s last year so why would you expect me to think you're going to replace this years $109 sacrifice? I seriously doubt I'm the only person who's seen this happen given that roughly 15% to 20% of the 6s 5000 mAh lipos I've bought from MRC have died after 6 months with one bad cell.

I was mad last night, but now I'm really pissed! I've had $218 worth of 6 month old batteries with less than 12 flights each die for NO RHYME OR REASON! MRC's lipo vendor knows what their failure rate is after 6 months as well as I and I'm certain others do. STAND BEHIND THE PRODUCT!
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Old 03-12-2018, 12:42 AM
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It'd better to discharge the lipos to storage mode if they are not in use for some time before they are put away
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Old 03-12-2018, 03:19 AM
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Originally Posted by Kevin2016 View Post
It'd better to discharge the lipos to storage mode if they are not in use for some time before they are put away
Yes, good advice to have LiPo cells at 3.8v when not using a LiPo battery.

Not sure if commenting on ftherrmann's post above yours, but the battery was put away at storage charge.
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