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Parallel Charging Question

Parallel Charging Question

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Old 11-30-2010, 11:52 PM
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Ok so I think I'm setup to charge my Losi Xcelorin 7.4v 5000mah 50C Lipos in Parallel with my TC 1030.

I have this charge adapter

and this balance adapter


to go to this balancer



Now here's my question. When I plug one battery into the balancer it shows as 2 cells, but when I plug 2 batteries in with the adapter it still shows 2 cells, but 1 cell will read the voltage of first battery and the 2nd shows up as the voltage of the 2nd battery (single cell not both cells)

Is this right? Will it cause a problem balance charging like this? Or should I check the balance of each individual battery before hooking them up to the balancer?
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Old 12-01-2010, 04:58 PM
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When you're charging in parallel, you will not see more than two cells regardless of how many lipos are connected. You are in effect charging a big two cell equivalent battery. The balancer sees each 'cell' as the average voltage of what's there. Say you're charging three 2S in parallel, thats physically a total of 6 cells. The balancer will see only 2 equiv cells and the voltage of each equiv cell is the average of the 3 physical cells on that side of the wiring.

The only thing that charges as we go to parallel charginjg 4 lipos is the equiv capacity gets bigger and now the 2 equiv cells the balancer sees will be the average of the 4 physical cells in that side of the wiring.

When you hook the lipos up, voltages equalize and this is the reason most advise that the voiltage be similar before connecting them.
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Old 12-01-2010, 07:41 PM
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Ok i see. So balancing isn't really necessary? I'll be charging a pair that I run in my 808-E as a 4s so should be fairly close voltage.
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Old 12-01-2010, 07:56 PM
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Balancing is still important, between the 2 groups of cells that are each paralleled.
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Old 12-01-2010, 07:59 PM
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OK so my setup will work for now until I can get a balance charger? Just keep the balancer plugged into the 2 batteries.
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Old 12-02-2010, 08:27 AM
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Originally Posted by Doxiedad View Post
OK so my setup will work for now until I can get a balance charger? Just keep the balancer plugged into the 2 batteries.
Your setup will work if you charge a single 2C battery with the balancer. If you add another battery pack in parallel, the balancer wont work as accurately since your balancing more than 1 cell per balance line.
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Old 12-02-2010, 08:42 AM
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Originally Posted by Doxiedad View Post
Ok i see. So balancing isn't really necessary? I'll be charging a pair that I run in my 808-E as a 4s so should be fairly close voltage.

The two 'equiv cells' still need to be balanced to each other.....

I don't see why your external balancer won't be as accurate for one lipo as two in parallel except for the averaging of the cells on one side versus seeing each physical individual cell.

I'd prefer to see all 4 cells personally, especially with my older lipos but its not an option unless you really understand what you're doing. Guy on RCG shorted a pr of lipos together trying to do it recently.
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Old 12-02-2010, 09:06 AM
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I've been parallel charging two 3s & two 4s lipos for a long time, I have tried every way you can do it.
I did not like putting any of the balance leads together.

I found using two of these balancers (or any balancers in stand alone mode) http://www.hobbycity.com/hobbycity/s...dProduct=10328 And charging strait to the lipo's is faster then charging through a balancer. I started doing it this way when I was using my ICE charger.
With my balancing charger and two balancers in stand alone mode I have balance charged 3x4s lipos = 12 cells.


The balancers will not stop the charge if one cell goes out of balance doing it this way.

I hope my post gives somebody another option.

Last edited by Lazer Guy; 12-02-2010 at 10:42 AM.
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Old 12-02-2010, 11:48 PM
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Ok now I'm a little confused. I'm not charging throught the balance leads. I'm charging through the charge leads. Are you saying that the Losi balancer won't stop the charging if they get out of balance?

I haven't actually done this yet, just looking at a way to keep enough batteries charged for my slash and 1/8 E buggy that runs 2 packs with only 2 chargers.
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Old 12-03-2010, 07:02 AM
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http://www.hobbycity.com/hobbycity/s...idProduct=7443
This type balancer with the main leads going thru the balancer and chargers with balancers in them will stop the charge if one cell gets way out of balance (around .5 difference is way out of balance)

Stand alone balancers will not stop the charge, some (but not all) will beep and or light up a fault/status LED to let you know you should take a look at whats going on.

A guy I know has been using that Losi balancer for a long time and he likes it.
Look in the manual and see what it does in a fault situation.

Last edited by Lazer Guy; 12-03-2010 at 11:02 AM.
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Old 12-03-2010, 02:19 PM
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Yeah my current setup isn't ideal. I'm hoping to be able to pick up a iCharger after Christmas, should work much better.
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