Sub_Umbra
Flashlight Enthusiast
Slight \'swelling\' on 9500mAH D NiMHs
I just noticed a slight swelling of the normally flat negative terminal of some of my 9500 mAH Powerizer D cells. I noticed this on one cell this morning and when I inspected the rest of them I saw that the negative terminal has become slightly dome shaped in four out of the fourteen cells I'm using.
Some details:
1--Sixteen cells were bought from BatterySpace ~eleven months ago. They were purchased to use as two six cell sets for my CD boom-box, two cells for my late model EL Hyper-Blaster, and two spares. All of the 'domed' terminals have occurred on the cells in the two six cell sets I rotate through the boom-box. I have a third six cell set from a different manufacturer that is part of the boom-box rotation -- they're all ok. Because there are three sets, each boom-box set gets recharged about once every 25 days. The Hyper-Blaster set only gets recharged ~half that much.
2--I'm using an AccuManager 20 for all of my charging. I rotate three sets for the boom-box because a six cell set actually takes over 2 days to charge in the four station AC2020. It has worked out quite well as it also keeps me reasonably stocked with D cells for blackouts -- I don't have to tap into the alkaline stash unless things get pretty serious.
3--I'm happy with the performance I've gotten from these cells so far and since I'm the only one who has ever handled them I can state with certainty that none of them have been dropped, etc.
I normally check the voltage of the cells before and after charging with a DMM but mine died last week. As soon as I post this I'm going to go out and get another. I haven't noticed anything odd in the readings so far.
Sooo, anyone have any idea what's going on here? Anyone seen this before? How concerned should I be? Are these cells heading towards catastrophic failure? Is this something I can live with as long as the cells will still physically fit into the device and charger?
Any help will be appreciated.
/blinks, scratches head
I just noticed a slight swelling of the normally flat negative terminal of some of my 9500 mAH Powerizer D cells. I noticed this on one cell this morning and when I inspected the rest of them I saw that the negative terminal has become slightly dome shaped in four out of the fourteen cells I'm using.
Some details:
1--Sixteen cells were bought from BatterySpace ~eleven months ago. They were purchased to use as two six cell sets for my CD boom-box, two cells for my late model EL Hyper-Blaster, and two spares. All of the 'domed' terminals have occurred on the cells in the two six cell sets I rotate through the boom-box. I have a third six cell set from a different manufacturer that is part of the boom-box rotation -- they're all ok. Because there are three sets, each boom-box set gets recharged about once every 25 days. The Hyper-Blaster set only gets recharged ~half that much.
2--I'm using an AccuManager 20 for all of my charging. I rotate three sets for the boom-box because a six cell set actually takes over 2 days to charge in the four station AC2020. It has worked out quite well as it also keeps me reasonably stocked with D cells for blackouts -- I don't have to tap into the alkaline stash unless things get pretty serious.
3--I'm happy with the performance I've gotten from these cells so far and since I'm the only one who has ever handled them I can state with certainty that none of them have been dropped, etc.
I normally check the voltage of the cells before and after charging with a DMM but mine died last week. As soon as I post this I'm going to go out and get another. I haven't noticed anything odd in the readings so far.
Sooo, anyone have any idea what's going on here? Anyone seen this before? How concerned should I be? Are these cells heading towards catastrophic failure? Is this something I can live with as long as the cells will still physically fit into the device and charger?
Any help will be appreciated.
/blinks, scratches head
