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Post by mattsedgley on Nov 30, 2008 23:42:15 GMT
Suprisingly the tittle doesn't reflect the thread!!
However i've been balance charging lipo's today.. out of curiosity how long does a lipo take to balance on your charger... at present my current lipo has been balancing for a little over 6 hours.. to be fair when i started 1 cell was .20V lower than the other (3.8/4.0)
i've never ballance charged this pack before, understandably one of my packs felt a little "dull" This is obviously the reason! my other pack is amazing!
I wondered how many other people had experienced such an imbalance and such a long time on the machine to level them back out!
Matt
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Post by Martin S on Dec 1, 2008 0:03:33 GMT
Suprisingly the tittle doesn't reflect the thread!! However i've been balance charging lipo's today.. out of curiosity how long does a lipo take to balance on your charger... at present my current lipo has been balancing for a little over 6 hours.. to be fair when i started 1 cell was .20V lower than the other (3.8/4.0) i've never ballance charged this pack before, understandably one of my packs felt a little "dull" This is obviously the reason! my other pack is amazing! I wondered how many other people had experienced such an imbalance and such a long time on the machine to level them back out! Matt The way I deal with Adams batteries is that we balance charge at home the day before racing, when there is more time and rarely balance at a meeting. However it never takes more than an hour. Some people say there is no need to balance, but a regular regeme is good I think. If they are taking a long time again next time I would send the batteries back to be tested. They shouldn't take that long |
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Post by yellowshark on Dec 1, 2008 8:59:19 GMT
about 45 mins for a "flat" pack, ie down around 6.5v Thats a 4900 pack
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Post by yellowshark on Dec 1, 2008 9:00:53 GMT
P.S. have you got a duff pack there Matt?
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Post by Simon Crabb on Dec 1, 2008 11:51:23 GMT
It's usual for 'first time' balancing to take a long time, but by a long time I mean maybe an hour, or two. But, it depends very much on the charger, it seems some balancing methods happens at the 'end' of the charge cycle, and hence at a very low current, so at 0.1A or something it can take ages.
But 0.2v out is a lot, that one cell might be quite flat compared the other one.
So did it finish, how long did it take?
My own regime is now to balance pretty much every charge, and when they are balanced all the time, they don't take any longer to balance charge, as there's not much balancing to do. I had one pack that seemed 'a bit soft' and a good few balance charges later it's a lot happier - so I feel balancing is pretty important to cell maintenance.
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Post by oldtimeracer on Dec 1, 2008 13:12:28 GMT
Must admit I always balance charge and have not had any problems. I recently bought one of the "Cell Doctors" from Terry that shows you voltage of each cell and balances them. Having done this on all 3 of my Lipo packs none of them took longer than 25 minutes.
The balance charging sometimes takes awhile. It seems to get to 0.1amp and sit there for 10 or 15 minutes before finishing. I suspect that what Simon says about balancing at the end of the charge could be true. Again none of my packs have taken longer than 70 minutes to fully balance charge and that was when I first bought them. Now thay take about 45 minutes each.
As others have said it would seem you have a duff cell there Matt or at very least a very mismatched pack.
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Post by yellowshark on Dec 1, 2008 13:25:30 GMT
The balance charging sometimes takes awhile. It seems to get to 0.1amp and sit there for 10 or 15 minutes before finishing. I suspect that what Simon says about balancing at the end of the charge could be true. I can't recall the details Ian but that is the way LIPO charging works. I often take mine off the charger at 8.38v |
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Post by keitheroonie on Dec 1, 2008 13:44:15 GMT
the worrying part is, if you've been charging a pack with a dodgy cell without balancing, the good cell will overcharge as the charger cuts out at 8.40V, putting the missing voltage from the bad cell into the good cell.
I would keep a close eye on it matt, balance it then do a five minute run and check the cell voltages with a digital multimeter to see if they differ (they should be pretty close) That will tell you if you've got a duff cell.
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Post by mattsedgley on Dec 1, 2008 22:47:20 GMT
OK so the charger times out at 160 minutes.. which is three hours.. it did that twice.. so thats six and then a further two so we're talking around the 8 hours mark.. however for probably seven and a half hours one cell was a 4.20 and the other was at 3.98 - they've now ballanced - well 4.19/4.20 so i'll run the pack for 5 minutes on wednesday and then check the volatages.. see what happens!!
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Post by mattsedgley on Dec 16, 2008 20:48:08 GMT
Lipo update!!
The lipo that was so far out of balance from one cell to another is now back up and working well - I ran it all day on Sunday.. noticed nothing different to usual, it did however discharge at considerably different rates between each cell, however it did bring itself back up to being level easily between races....
Interestingly the very first lipo I bought.. a demon 5000mah (the blue one) i'd never balanced it before sunday evening.. and it was exactly right from one cell to another.. after 5 months of running with no balance amazing!!
This Lipo thing is all very interesting!!
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