Charging NiMH Batteries with Maha C-9000 Charger

[Scooby Doo]

In a post I had posted earlier, I asked for the appropriate charge rate for Duracell Rechargeable AA 2650 mAh batteries. Someone had recommended that the charge rate should be somewhere between 0.5C to 1.0C. This allows for the battery to be charged without over heating and allow for it to maximize its life.

So for a batter like the one above, charging at 1.0C, I would set the Maha C-9000 charger to charge at 2650 ma (1 X 2650 mAh) rate. This charger only allows for a maximum charge rate of 2000 ma; therefore, I can only charge at 2000 ma for each Duracell Rechargeable 2650 mAh battery. Is this correct?

To use another example, assume I'm using a Duracell Rechargeable AAA 800 mAh batteries. The charge rate I would use for this charger is 800 ma (1.0 X 800 mAh). Is this correct?


Thanks.

 

[Mr Happy]

1.0C is the safe maximum. Personally I would use the 0.5C rate or even just the 1000 mA default charge rate for AA cells unless I am in a hurry. With modern high quality cells the C9000 is quite good at terminating even at lower charge rates.

So with the 800 mAh AAA cells, I would tend to charge them at 400 mA.

 

[MarioJP]

Speaking of the of the Duracells 2650? I am not having any good luck with these batteries, in fact the moment its fully charge after i use my battery tester, which reports all green 5 led each one representing 20%.

I leave them only for a day just sitting there and i would test them again and it is down to 3 led lit which the battery is at 60%!!.

What gives i did not even use these batteries.

 

[VidPro]

Speaking of the of the Duracells 2650? I am not having any good luck with these batteries, in fact the moment its fully charge after i use my battery tester, which reports all green 5 led each one representing 20%.

I leave them only for a day just sitting there and i would test them again and it is down to 3 led lit which the battery is at 60%!!.

What gives i did not even use these batteries.

Notes: some testers do not apply a load, so they cant always tell much about a battery, because you didnt say Which tester.

they suck , high cap ni-mhy cells are having way more self discharge after less than 50 cycles and less than 2 years of use. they still can often be usable for daily use when just charged and all, but for sporatic use and sitting for time a person is FAR better off switching to LSD cells of any type.

also because the capacities differ over time (after charging), they are more prone to the "user" getting them in a situation where they get reverse charge in Series. One cell is out of capacity before the others and the low cell gets slammed with a reverse charge.
that reverse charge stuff makes things Worse Still, compounding the problem drastically, making the whole series team thing spiral down into completly unusable over time.

for normal rechargable ni-mh use switch to LSD , and be free of the burdon, use the high-caps for daily right off the charger stuff instead.

 

[45/70]

I've rid my collection of high capacity AA and AAA (>2000/800mAh) cells. None of them held up for very long before high self discharge set in. I will say the Sanyo 2700's were probably the best, but I just don't want to mess with them anymore. The highest capacity AA's I have now, are eneloops, followed by some 1800 and 1200mAh standard NiMH AA's. Most of the later two are more than 5 years old and should probably be recycled, but I have to say, compared to the high capacity cells I've had, they have served well.

While I've never owned any Duracell 2650's, I suspect they're suffering from the same problem. Mario, I hate to say it, but your cells are most likely, suffering from the "high capacity cell blues". You may try to revive them since they haven't really been used, but......

Scooby, I share Mr H's view on charging. I usually charge my eneloop's at 1000mA, particularly in the summer when it's hot. If I need a bunch of cells in a hurry, for my camera's for instance, I'll charge them at 2000mA, but try to avoid it if the room temp is really warm. So for your 2650's, I'd go with 1300-1400mA most of the time and 2000mA in a pinch.

Dave

 

[1anrm]

This is what I like about the C9000 it defaults to 1000ma charge rate. I'm tired of having to press and wait for the BC900 to get to 1000ma to charge my AAs. I'll watch out for deal on a C9000.