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HelicopterMain Discussion › Unbalanced cells after flying
06-09-2014 02:21 AM  3 years agoPost 1
nick.gruber

rrApprentice

Lincoln, NE

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Is it common for cells to be unbalanced after flying. I finished flying my Goblin today and some of the cells on the Thunder Power batteries were 3.00 and others were 3.60. I know I ran the batteries too low. Also, is it common to only get three or four minutes of flight time doing just some sport flying? The batteries are 4400mAh.

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06-09-2014 02:47 AM  3 years agoPost 2
unclejane

rrElite Veteran

santa fe, NM, USA

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Well, if the cells aren't completely even in capacity yes. I have a couple of 6S flight packs that go out of balance after a couple flights.

If you measure the IR, chances are you'll get different figures on the batt that's doing that. Variations of 2 or more milliohms will tell the tale there. That's what I see on my 6S packs that unbalance right away.

I just balance charge those particular packs by themselves on my powerlab every time or maybe every other time if I'm lazy....

LS

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06-09-2014 05:17 AM  3 years agoPost 3
Flyin for Jesus

rrVeteran

Troy, IL. 62294

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.6V sounds like a lot to me... my 6s packs came down today no more than 10mV difference.
I do have new packs though.

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06-09-2014 05:43 AM  3 years agoPost 4
3dgimble

rrKey Veteran

Rochester

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.6V sounds like a lot to me
Agreed. Now for 4 mins of flight time on 4400 could be normal for sport flying.

But for that sorta flight time, you may be running a high head speed and or a high wattage motor or over geared it.

Furthermore the TP may have been run down low too may times low, or may have more than there share of flights, that may be the culprit for unbalanced cells.

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06-09-2014 01:27 PM  3 years agoPost 5
kingmeow

rrApprentice

The Garden State, US

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Is it a new pack? If so, take it easy on it for a few cycles. Often new packs don't balance as well as a well used one. Also capacity doesn't reach 100% until a few cycles later.

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06-09-2014 01:49 PM  3 years agoPost 6
Ace Dude

rrProfessor

USA

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At 3.0V/cell those cells have been over discharged. Ideally you never want to discharge a pack below 20% of its capacity. Over discharging a pack will ruin it in short order.

  

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HelicopterMain Discussion › Unbalanced cells after flying
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