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battery discharge question

battery discharge question

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Old 09-25-2004, 03:28 PM
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I have a LRP Pulsar Competition charger and I was wondering what a good discharge voltage is for my 2400 nicd's and my 3300 nimh batteries?
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Old 09-25-2004, 06:11 PM
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csilve,

Multiply the number of cells your discharging by .9v.
six cell = 5.4v
four cell = 3.6v
That's the pack cutoff voltage setting for your charger.
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Old 09-25-2004, 06:30 PM
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i would recommend 6.0V cause if you set it at 5.4V cutoff you are risking of overdischarging one of your cells below its intended cutoff volts of .9

since .9V x 6 cells = 5.4 cutoff (5.4 cutoff is purely theoretical cause not all cells have exactly the same voltage at the same time.)
most often one or two cells have gone below the .9 cutoff when you cutoff at 5.4

why dont you pullout your multi-tester and see it for yourself.

Last edited by S-T-R-l-K-E-R; 09-25-2004 at 06:43 PM.
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Old 09-25-2004, 08:53 PM
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I suggest going to your battery matchers web page and reading up on their reccomended discharge procedures
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Old 09-25-2004, 10:41 PM
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Originally posted by S-T-R-l-K-E-R
i would recommend 6.0V cause if you set it at 5.4V cutoff you are risking of overdischarging one of your cells below its intended cutoff volts of .9

since .9V x 6 cells = 5.4 cutoff (5.4 cutoff is purely theoretical cause not all cells have exactly the same voltage at the same time.)
most often one or two cells have gone below the .9 cutoff when you cutoff at 5.4

why dont you pullout your multi-tester and see it for yourself.
This problem is lesser with matched cells. But it's true, it's a downside of discharging as a pack.

But usually it works well anyway, because at higher loads, the IR in the pack result in a larger voltage drop, so when the discharger cuts off, there's still a reasonably amount of charge in each cell. Next step is to put the pack on an equalizer, which further will prevent this problem.
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