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Old 12-29-2009, 08:01 AM   #6 (permalink)
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This is exactly how our design will work except we will not be going for a 100% charge on the top end. We have found these cells too finicky on the upper range limits.

Originally Posted by smokeyj View Post
Li ion cells are usually charged with a CC (constant current) CV (constant voltage) followed by float (disconnect from power source) technique.

Charge current can be as high as the amp-hours of the pack, voltage limit is usually 4.1 or 4.2V (for laptop cells) and needs to be quite precise. There is no temperature correction for this. Once the cells have reached constant voltage the charge current decreases. You can either disconnect at C/10 (about 95% charged) or run a timer for an hour or two.

You don't want to keep the cells attached to the charge voltage once they have reached 100% charge.
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