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Old 09-28-2008, 10:40 PM   #1
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Default Bad Lipo cell? or what?

I've got a Reedy 5000 lipo that is about 6 months old. Always run with an ESC with lipo cutoff and it had only hit the cutoff once till a week or so ago. We were running in an enduro and at about 19 minutes the guy that was driving hit a board pretty hard and it studdered and shut off. Ok so I thought the high draw from the crash caused the shut down. Well as I thought more it bothered me that we only got 19 minutes considering our other batteries were getting 27+ minutes (losi 5000).

Well I have never balanced it but bought an Equinox balancer to check it out. Plugged in this morning and it looked like it was trying to balance... I got impatient after about 10 minutes and decided to balance discharge it with the ICE/balancer... still didn't balance... so I put it on a CORE UDC-20 so I could see the cell voltage. Cell 1 - 3.75V, Cell 2 - 4.2V.... but it never seemed to change (1 1/2 hr on charger). So I went back to the Equinox/ICE... tried to balance again... no luck. Back to the Core... 1 -3.9V 2 - 4.2.... ok getting closer but 1 1/2 hours later it was still the same. So I hooked in up on the Equinox for what they call Quick Balance..... now 7 hours later it is still blinking.

No swelling of the pack... I can't tell any difference in performance... I just can't seem to get it to balance. Do I have a cell bad/going bad? Do I just need to wait it out?


Oh one last thing... when I charged it I never got more than 2500mah into it or out when I discharged (3.0V cutoff).
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Old 09-29-2008, 03:20 AM   #2
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The balancing will take forever due to the thiness of the balancing plug wires and the you have a large diff between cells
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Old 09-29-2008, 03:58 AM   #3
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i would check it out but it sounds like you have a 4 cell pack and you my have one bad cell.
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Old 09-29-2008, 05:16 AM   #4
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I have only ran lipo for a few weeks, but I learned that I need to balace every few charges, I look at the voltages everytime I thake the truck off the track.
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Old 09-29-2008, 08:41 AM   #5
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Quote:
Originally Posted by Drifting101 View Post
The balancing will take forever due to the thiness of the balancing plug wires and the you have a large diff between cells
I have never had this large a difference in cells ever before, in fact my other packs have never been out of balance which is why I wasn't in a big hurry to get a balancer for this pack. So I get up this morning and the balancer shows that it is done.... wow you were not kidding about taking forever. Hopefully its taken care of now.

Quote:
i would check it out but it sounds like you have a 4 cell pack and you my have one bad cell.
How would I check it out?

Anyone know how to check the voltages of this pack (Deans/JST XH) with a multimeter. Or will I have to hook it up to something like the CORE UDC-20?

Is this sort of imbalance ok or a sign of bad things?
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Old 09-29-2008, 08:57 AM   #6
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Quote:
Originally Posted by padailey View Post
I have never had this large a difference in cells ever before, in fact my other packs have never been out of balance which is why I wasn't in a big hurry to get a balancer for this pack. So I get up this morning and the balancer shows that it is done.... wow you were not kidding about taking forever. Hopefully its taken care of now.



How would I check it out?

Anyone know how to check the voltages of this pack (Deans/JST XH) with a multimeter. Or will I have to hook it up to something like the CORE UDC-20?

Is this sort of imbalance ok or a sign of bad things?
What we have seen here with my sons packs, reedy 5000 and 3200, is that we have to at least check them every charge cycle.If they go way out of balance it will take at least 5 charge cycles to bring them back in. I have not tried them with a charge through balancer, so they make take a little longer. I use the Common Sense Balance Pro with a reverse polarity adapter on the Ice Charger and it works just fine after they came back in balance.

You should be able to check your cell voltages thru you JST/balance plug, red wire and first black should be 1 cell and black/black should be 2nd cell, 1st and 3rd entire pack.
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Old 09-29-2008, 09:54 AM   #7
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my maxamp 4400 saddle pack for the b44 has a bad cell from what I can tell. balancing most times would take forever (30min or more), but sometimes not and I'd think it was fine... It'd charge ok after balancing but after a few min. of running it freaks out (gliches, cuts off, etc)..
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Old 09-29-2008, 10:39 AM   #8
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Thanks guys... guess I'll just have to watch it a little closer and balance it a little more than I am used to. Hopefully it will be ok.

I wish they could work out some standard for balancing taps so I wouldn't have to have multiple balancers and/or adapters. A buddy of mine and I have 1 orion, 1 trakpower, 1 reedy, 2 maxamps, and one Losi.... other than the orion and trakpower being the same they all have different balancing taps! Grrrrr... still haven't figured out yet what the Losi tap is.
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Old 09-29-2008, 10:41 AM   #9
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I have a Yeah Racing 3200 pack with huge different voltage between cells. The balancing take around 6hrs to complete. Try to leave it to the balancer. It will surely balance it out but of course might take a while to finish.
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Old 09-29-2008, 11:05 AM   #10
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Quote:
Originally Posted by padailey View Post
Thanks guys... guess I'll just have to watch it a little closer and balance it a little more than I am used to. Hopefully it will be ok.

I wish they could work out some standard for balancing taps so I wouldn't have to have multiple balancers and/or adapters. A buddy of mine and I have 1 orion, 1 trakpower, 1 reedy, 2 maxamps, and one Losi.... other than the orion and trakpower being the same they all have different balancing taps! Grrrrr... still haven't figured out yet what the Losi tap is.

Losi should be a JST XH plug as stated by http://www.rclipos.com/Accessories.htm but I do believe it is actually a thunder power plug, might be wrong though.
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Old 09-29-2008, 11:17 AM   #11
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Quote:
Originally Posted by ercwhtsd View Post
Losi should be a JST XH plug as stated by http://www.rclipos.com/Accessories.htm but I do believe it is actually a thunder power plug, might be wrong though.
Well the Reedy is a Align/JST XH... right? ... well the Losi is considerably smaller. I believe the TP plugs are smaller than most so I would tend to agree with you.
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