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Old 05-23-2006, 03:01 AM   #1
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Default Batteries not fully Charging help!!!

ok ive had my batteries from new they are gp3700, i charge a 6 amps discharge at 10 or in the car with a stock motor. i use a duratrax ice with a 4mv sensitivity and 118'f temp cutt off i discharge and then let them equilize on a smart tray to .9v problem is when i charge them they only take in about 3000mah and on dicharge the give out bout 2400 2600mah
the charger says they have a resistance of 56m ohm
does any one have an idea whats wrong i also tried the cell on another charger and it chager to 2900 before temp cutt of?? im going to cycle them tonight to see what happends but i dont get why they wont fully charge???
please help
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Old 05-23-2006, 04:26 AM   #2
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I was having the same probs with my IB3800`s & IB3600`s (old), charging with a Supernova Competition @ 6amps & 4mv, discharging @ about 20amps with bulbs & then traying with a Smart Tray to 0.9v.

An electrician racer mate suggested to up the delta peak to around 10-15mv being old cells.... & they are now taking around 4000 to 3900 respectlively.

So maybe give that a try

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Old 05-23-2006, 05:19 AM   #3
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Try it without the temp guage as well.. see if it fully charges then..
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Old 05-23-2006, 02:10 PM   #4
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Contrary to IB/Intellect cells GP3700 cells (which can break below 0.9v) need to be discharged much further. You can discharge each cell to 0.5v without problems and some drivers, for instance from Team Trinity, even short circuit them during storage. I leave my GP3700s in a normal discharge tray for 24 hours so the cells are just about at 0v. Then I leave them for a couple of days and charge them at 6a just like you do. Depending on the charger you should be able to put anything between 3900-4500 Mah in them with a peak cutoff of 4mV or 5mV per cell. Power will be much better as well as runtime!

DO NOT do this with IBs or Intellects!!! These should not be discharged lower than 0.9v per cell.
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Old 05-24-2006, 05:42 AM   #5
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ok isnt 10mv really high and ive been told not to go below .5v by Issac at Axxis racing just checking?
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Old 05-24-2006, 10:56 AM   #6
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I haven't had any problems with going down to 0V with GP3700s when using a discharge tray as described above. I tried going down to 0.5V when the GP3700s had just come out and had the same problems you have: lower capacity and less punch. That's why I tried deep discharging and found the GP3700 batteries performed much better that way. Suddenly I was able to make my runtime again and had more speed and punch to boot. I have yet to blow a GP3700 cell despite doing this for a long time now.

With IB cells however 0.9V per cell is the limit as I have seen multiple persons blow these types of cells after discharging them a little too deeply. I am not sure yet about GP4300s.

10mV per cell for peak cutoff is indeed very high and I would not recommend it for either GP or IB cells. The most I have used is 5mV per cell which is ok for GPs but already on the high side for IB cells (this can also cause cells to break).
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