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HP Forum Archive 13

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New cells for the 41Cīs battery pack
Message #1 Posted by Jon on 8 Nov 2003, 10:56 a.m.

I have repaired a dead battery pack 82120A. I have used new 1/3AAA NiMH cells (150mAh). I have charged it for three hour with the adapter 82059D and it works just fine. I have charged just three hours because I know the rechargeable cells are very sensitive to overcharge. I would like to know how long must I keep it charging for a full charge. I think original cells are 1/2N NiCd (75 mAh aprox.) so the total charge time should be the double. Does anybody know the recommended charging time for the original battery pack?.

Thanks in advance


82120A charging rates and 1/3AAA cells
Message #2 Posted by Randy Sloyer on 8 Nov 2003, 6:08 p.m.,
in response to message #1 by Jon

The 82120A manual says 12 to 16 hours for a full charge.

With respect to the 1/3AAA cells, Gold Peak says 16 ma for 16 hours. It just so happens the charge rate of the 82120A is 16 ma. So 16 hours should yield a fully charged pack.

They will typically reach 5.80 volts open circuit when fully charged. I have seen no cell heating (checked with I/R thermometer) after 24 to 36 hours so I would not be overly concerned about overcharging. I charged one for a week once to see what would happen - it seemed to decrease its capacity until it went through two or three discharge charge cycles - it now seems fine and maintains a 16 ma discharge rate for about 10-12 hours.

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