constipated
Newly Enlightened
- Joined
- Nov 7, 2009
- Messages
- 9
I've been trying some cheaper standard NiMH, the Aldi Ultracell 2500 mAh.
Using the break-in function my first impressions were that the cells did not live up to capacity with 3 being around 2200 mAh, and 1 being 2050 mAH.
They were put into a baby monitor that gets continuous use. They were regularly recharged even when only half empty to eliminate reverse charging possibilities.
They were charged only in the C9000. My observations were that charging at 1200 mA (approx 0.5C), they never got up to 1.47V like eneloops to terminate. Instead they remained at max 1.43V.
I was hoping they would terminate under -delta V. They eventually did seem to terminate but each time would get extremely hot, way past being able to comfortably hold. This is in comparison to eneloops which are barely warm out of the charger. My concern was that they were terminating due to overheating.
Now about 4 months after I purchased them, I did a refresh and analyse, and the cells range from 1510mAh to 1715mAh. Initial impedance is still low at around 1.55 on initially inserting in to the Maha.
Surely they must have been damaged from the overheating.
My question now is what is the best way to continue charging these cells. To use a lower charging rate. This could however cause problems with missed termination and not cause sufficient temperature rise to terminate that way.
Obviously to continue with what i'm doing is to send them to an early grave anyway.
Suggestions?
Using the break-in function my first impressions were that the cells did not live up to capacity with 3 being around 2200 mAh, and 1 being 2050 mAH.
They were put into a baby monitor that gets continuous use. They were regularly recharged even when only half empty to eliminate reverse charging possibilities.
They were charged only in the C9000. My observations were that charging at 1200 mA (approx 0.5C), they never got up to 1.47V like eneloops to terminate. Instead they remained at max 1.43V.
I was hoping they would terminate under -delta V. They eventually did seem to terminate but each time would get extremely hot, way past being able to comfortably hold. This is in comparison to eneloops which are barely warm out of the charger. My concern was that they were terminating due to overheating.
Now about 4 months after I purchased them, I did a refresh and analyse, and the cells range from 1510mAh to 1715mAh. Initial impedance is still low at around 1.55 on initially inserting in to the Maha.
Surely they must have been damaged from the overheating.
My question now is what is the best way to continue charging these cells. To use a lower charging rate. This could however cause problems with missed termination and not cause sufficient temperature rise to terminate that way.
Obviously to continue with what i'm doing is to send them to an early grave anyway.
Suggestions?
