Preventing a Reverse Charge

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CEHepp
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Preventing a Reverse Charge

I have one multi cell light and I was wondering what the best way was to prevent a reverse charge of the cell. Is turning the light off when it gets dim good enough to prevent damage to my sensitive batteries?

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agenthex
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The best way is probably to check w/ voltmeter before you stick them in. As long as they're reasonably matched pair, you're fine. Also might be good idea to check volts when taking them out to charge, just to be sure they're similar. What you really need to prevent is inserting one full and one empty one, or one old and one new one.

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CEHepp
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agenthex wrote:

The best way is probably to check w/ voltmeter before you stick them in. As long as they're reasonably matched pair, you're fine. Also might be good idea to check volts when taking them out to charge, just to be sure they're similar. What you really need to prevent is inserting one full and one empty one, or one old and one new one.

 

So, even in a series configuration with two equally charged cells, I should be good to go till the light is reasonably dim without reverse charging one of the cells?

I'm concerned because I have read about the "instant death" experienced by NiZn cells that get a reverse charge.

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agenthex
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Yeah, with reasonably similar cells they should be at near same voltage at the same point in time, so one can't really reverse charge the other (which still takes significant current). Lithium cells voltage curves are pretty linear.  Basically, just use two of the same batch/kind batteries, and run the light down once and check to make sure voltage is about the same.

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CEHepp
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agenthex wrote:

Yeah, with reasonably similar cells they should be at near same voltage at the same point in time, so one can't really charge the other.

Nice! That makes me feel a lot better because I do like this ThruNite...even if it is warm white.

Zebralight S6330 – Zebralight SC600w – Zebralight SC52 – Zebralight SC51w – EagleTac D25A Ti 219 – 4Sevens Quark Turbo AA2 219 – FourSevens Preon PenLight -