mountaindewer
Newly Enlightened
- Joined
- Apr 24, 2013
- Messages
- 72
I've been watching my C9000 here lately when it comes to charging, and I've noticed that slot 1 differs in readings compared to the other 3 slots. slot 1 ALWAYS gets done first, sometimes by at least 7 or so minutes. And it always has the widest spread as well.
Another thing I've noticed, is that this spread differs on how far the batteries were run down. If I run them down and put them in to charge and the initial voltage when the charger starts to charge is like 1.22v, then the spread on this charge will be wider, compared to if I put them on, and the voltage reading at the start of the charge was like 1.28v or so. And yes, I'm talking about the voltage when it first starts charging, NOT the internal resistance check voltage. And what I mean by that, is if I start a set of batteries charging on the initial voltage of 1.22v, slot 1 will finish at like 8 minutes before the others and the spread will be like 150. But if I start the same set of batteries charging at 1.28v, then slot 1 will finish like 5 minutes before the others and the spread will be like 100. So it seems like the further they are ran down and then charged, the bigger the spread, and the shallower they are ran down and then charged, the smaller the gap.
For example, I wrote down the numbers on some AA Eneloop pro's. When I was done with them, I put them in the charger. The starting volts on load from the charger was 1.22v. When all was done, as usual, slot 1 got done first at 2004 mA @ 111 minutes. Slot 2 was 2136 mA @118 minutes. Slot 3 was 2122 mA @ 117 mins. Slot 4 was 2120 mA @ 117 minutes. So with these numbers, slots 2-4 all finished up within 1-2 minutes of each other, and the spread was very thin between them. But slot 1 ALWAYS seems to undercharge, and in this case, 2136 was the highest of all 4, and 2004 was the lowest of the 4. That's a spread of 132 mA. Compared to slots 2-4, 2136 being the highest and 2120 being the lowest, is a spread of 16 mA. So slots 2-4 always finish around the same minute or so, and have a very small spread, while slot 1 is ALWAYS the odd one out.
Now If i was to put them in the charger this time, and the starting volts under load on the charge was 1.3v, the spread this time would be slightly smaller. Slot one would, as usual, finish first and slot 2-4 would finish together, but the spread this time around would be slightly smaller. It seems like the deeper the batteries are discharged, the wider the spread is between slot 1 and the other 3 slots. And the shallower the discharge of the batteries, the closer the spread between slot 1 and the other 3 slots, however, the spread is still off compared to the other two.
It does it with every batteries that I have together in a "set" for a device. Like 2 batteries that get charged together for this device, 4 batteries that get charged together for this device, etc.
I always charge at the rate of 0.5C, and it does it with every battery, be it normal Eneloops, Eneloop pro's, Energizers, etc.
Now, here's the kicker. Even though slot 1 always seems to undercharge, when I let the batteries sit on the 2 hour top off, and I then run them down on a discharge, the numbers are even. Even though slot 1 appears to undercharge by at least 125+ on my Pro's, when I let them sit on the 2 hours top off and then discharge, the numbers are consistent with each other.
Here's the numbers I got after the charge.
slot 1: 2004
slot 2: 2136
slot 3: 2122
slot 4: 2120
So the gap from the highest (slot 2) to the lowest (slot 1) is 132. I then let them set on the 2 hour top off. I then left the batteries in the same slots that they were in, then unplugged the cable, then plugged it back in, and ran them through a discharge of 0.25C, so 600 mAh for these batteries
Here's the numbers I got after the discharge.
slot 1: 2457
slot 2: 2460
slot 3: 2434
slot 4: 2475
The gap this time from the highest to the lowest, was just 41.
For another real quick example, I charged some 2700 powerex AA's, and the gap between slot 1 and the rest were like 12 minutes and easily a gap of 287 mA. But after the 2 hour top off, I discharged them and on the discharge numbers, the gap then was narrowed down to a difference of 37 mA.
So why is it that when charging, slot 1 always seems to UNDERCHARGE compared to the rest of the slots, but then when you put them through a discharge, the numbers seem to be fine?
Another thing I've noticed, is that this spread differs on how far the batteries were run down. If I run them down and put them in to charge and the initial voltage when the charger starts to charge is like 1.22v, then the spread on this charge will be wider, compared to if I put them on, and the voltage reading at the start of the charge was like 1.28v or so. And yes, I'm talking about the voltage when it first starts charging, NOT the internal resistance check voltage. And what I mean by that, is if I start a set of batteries charging on the initial voltage of 1.22v, slot 1 will finish at like 8 minutes before the others and the spread will be like 150. But if I start the same set of batteries charging at 1.28v, then slot 1 will finish like 5 minutes before the others and the spread will be like 100. So it seems like the further they are ran down and then charged, the bigger the spread, and the shallower they are ran down and then charged, the smaller the gap.
For example, I wrote down the numbers on some AA Eneloop pro's. When I was done with them, I put them in the charger. The starting volts on load from the charger was 1.22v. When all was done, as usual, slot 1 got done first at 2004 mA @ 111 minutes. Slot 2 was 2136 mA @118 minutes. Slot 3 was 2122 mA @ 117 mins. Slot 4 was 2120 mA @ 117 minutes. So with these numbers, slots 2-4 all finished up within 1-2 minutes of each other, and the spread was very thin between them. But slot 1 ALWAYS seems to undercharge, and in this case, 2136 was the highest of all 4, and 2004 was the lowest of the 4. That's a spread of 132 mA. Compared to slots 2-4, 2136 being the highest and 2120 being the lowest, is a spread of 16 mA. So slots 2-4 always finish around the same minute or so, and have a very small spread, while slot 1 is ALWAYS the odd one out.
Now If i was to put them in the charger this time, and the starting volts under load on the charge was 1.3v, the spread this time would be slightly smaller. Slot one would, as usual, finish first and slot 2-4 would finish together, but the spread this time around would be slightly smaller. It seems like the deeper the batteries are discharged, the wider the spread is between slot 1 and the other 3 slots. And the shallower the discharge of the batteries, the closer the spread between slot 1 and the other 3 slots, however, the spread is still off compared to the other two.
It does it with every batteries that I have together in a "set" for a device. Like 2 batteries that get charged together for this device, 4 batteries that get charged together for this device, etc.
I always charge at the rate of 0.5C, and it does it with every battery, be it normal Eneloops, Eneloop pro's, Energizers, etc.
Now, here's the kicker. Even though slot 1 always seems to undercharge, when I let the batteries sit on the 2 hour top off, and I then run them down on a discharge, the numbers are even. Even though slot 1 appears to undercharge by at least 125+ on my Pro's, when I let them sit on the 2 hours top off and then discharge, the numbers are consistent with each other.
Here's the numbers I got after the charge.
slot 1: 2004
slot 2: 2136
slot 3: 2122
slot 4: 2120
So the gap from the highest (slot 2) to the lowest (slot 1) is 132. I then let them set on the 2 hour top off. I then left the batteries in the same slots that they were in, then unplugged the cable, then plugged it back in, and ran them through a discharge of 0.25C, so 600 mAh for these batteries
Here's the numbers I got after the discharge.
slot 1: 2457
slot 2: 2460
slot 3: 2434
slot 4: 2475
The gap this time from the highest to the lowest, was just 41.
For another real quick example, I charged some 2700 powerex AA's, and the gap between slot 1 and the rest were like 12 minutes and easily a gap of 287 mA. But after the 2 hour top off, I discharged them and on the discharge numbers, the gap then was narrowed down to a difference of 37 mA.
So why is it that when charging, slot 1 always seems to UNDERCHARGE compared to the rest of the slots, but then when you put them through a discharge, the numbers seem to be fine?
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