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Joined: 11/8/2007 From: Novato, CA, USA Status: offline
Success! Well so far. I figured out a way to rebalance your 2s batteries without the need to buy expensive chargers. I’m not sure if this has already been done but I did several searches on google/yahoo/forums and came up with nothing. I’ve been flying with my two stock e-flite batteries for months now and have about 200-300 flights through them using only the E-Flite and Venom charger/balancer. I used to average about 8-9 minutes of flight per battery until just this week when I started to notice my flights dropped down to 5-6 minutes. So I took out my Volt meter and checked each cell, sure enough the cells were unbalanced on a full charge. One cell read just below 4v’s and the other was at 4.2v’s. I spent a whole day trying to get them rebalanced with the chargers by unplugging and replugging them in, I even slightly drained them and tried milking the charger but they won’t level out. So this is what I ended up doing and testing,
1. Tested each cell on a full charge with a volt meter 2. Plug a 5v LED light onto the stronger of the two cells (needs to be at least 5v LED, anything else will fry. I think blue LED’s can handle higher voltage) 3. Let it drain that cell for about ……….5 hours (every 20-30 minutes check on it with your volt meter) 4. Once the cell has level out even with the other, then just recharge it on your charger. It should now charge balanced.
I still haven’t figured out the long term affects and have only tested it twice. I’m getting my full 8-9 minute flights back and the cells seem to be keeping balanced after each dis/recharge. I’ll see how long it last, and hope others will assist me in this testing and keep everyone posted on it.
Please look closely at the pictures below and take note on all the arrows to see how to test each cell.
< Message edited by eat2muchrice -- 1/26/2008 6:40:55 PM >
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I still think that eat2muchrice is a goofy name. But you seem to be nearly brilliant, so I suppose I can't pick on you too much. That was a really good idea - and simply brilliant in it's simplicity!
Good work. The Collective thanks you.
Soloboss
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Soloboss If everyone''s thinking alike, then somebody isn''t thinking . . . G. Patton
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Joined: 12/14/2007 From: Orlando, FL, USA Status: offline
Well..........put a DVM on my offending lipos as well as me good DN's and found that oddly enough they measure the same (basically) hmmmmm......now keep in mind DVM's as nifty as they are do not put any kind of "load" on the thing that is being measured. Whereas the old school analog meters do. Me thinks I will follow this further as the batts die. Good work and direction!
Rikybob
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"Trust, then verify"; or: Calm dayz and long lipoz!
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Joined: 11/8/2007 From: Novato, CA, USA Status: offline
Its the Collective that the thanks should go to. Just 5 months ago I didn't know cr@p about anything dealing with rc helicopters, I didn't even know what a balance plug was . It was everyone in this forum that has tought me the ways of the heliforce.
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quote:
ORIGINAL: eat2muchrice 2. Plug a 5v LED light onto the stronger of the two cells (needs to be at least 5v LED, anything else will fry. I think blue LED’s can handle higher voltage)
Posts: 99
Joined: 1/4/2008 From: Moon Township, PA, USA Status: online
How do you ck the ballance on a 2cell and a 3 cell lipo. I have a volt meter buy dont know what leads to but the red and black wires to . I use it on the end that plugs into the hile to see if it is fulley charged or how much it is discharged. I guess you use the white plug that goes into yhe charger buy what wires do you use, on the 3cell i have a black yellow blue and red. and on the 2cell i have a black abd two red on the white plug. Carl
Posts: 99
Joined: 1/4/2008 From: Moon Township, PA, USA Status: online
I think I figured it out. on the two cell my 3 Mega Power 4.15-4.17 next two 4.20-4.22 the 2 cell E-flite reads 4.02-4.01 My e-flite 3 cell 4.15-4.16-4.16 I use the e-flite charger that came with the CX2 to charge the CX2 batterys and the CP Pro batterys. Carl
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Joined: 11/8/2007 From: Novato, CA, USA Status: offline
quote:
ORIGINAL: gnd2
quote:
ORIGINAL: eat2muchrice 2. Plug a 5v LED light onto the stronger of the two cells (needs to be at least 5v LED, anything else will fry. I think blue LED’s can handle higher voltage)
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Joined: 1/2/2008 From: Whitby, ON, CANADA Status: offline
Does anyone have a recommendation as to when they would balance with this method? For instance, when one cell is +/- 0.1 volts different than the other? With the DVM my cells read 4.17 and 4.21 at full charge using eflite stock charger. Is this close enough?
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BATTERY FIX ! How To Rebalance Lipo's - 
. It was everyone in this forum that has tought me the ways of the heliforce.
. You can fine tune your