Maha 10 AH D Cell Problem

[beamis]

I received 8 of these cells as a gift, but they can't run in my Maglite for more than about 45 seconds. When I run them through a cycle on the Maha C-808M, it takes less than 20 minutes. They were purchased from Thomas Distributing, so I wouldn't expect 8 dead cells. Any ideas?

This is bumming me out extra since I also received four packs of Eneloops as a gift and it turns out they're Chinese counterfeits. They even have the vent holes and the squarish positive button correct, but when they would only discharge 100 mAh at 1000 mA I was suspicious. When they output only 1.15V after 15 minutes at 1000 mA I knew they were fakes. These dishonest Chinese battery suppliers are really starting to get on my nerves.

 

[Mr Happy]

I received 8 of these cells as a gift, but they can't run in my Maglite for more than about 45 seconds. When I run them through a cycle on the Maha C-808M, it takes less than 20 minutes. They were purchased from Thomas Distributing, so I wouldn't expect 8 dead cells. Any ideas?

This is bumming me out extra since I also received four packs of Eneloops as a gift and it turns out they're Chinese counterfeits. They even have the vent holes and the squarish positive button correct, but when they would only discharge 100 mAh at 1000 mA I was suspicious. When they output only 1.15V after 15 minutes at 1000 mA I knew they were fakes. These dishonest Chinese battery suppliers are really starting to get on my nerves.

It's possible you might be leaping to conclusions here.

Both the D cells and the Eneloops may need a few conditioning cycles before they perform at full strength. Firstly, what was the voltage on the D cells when you received them and before you charged them? Secondly, note that brand new cells can be difficult to charge since they sometimes give an early termination signal and fool the charger into stopping the charge early on. What you need to do is put them on a regular charge cycle and keep putting them back on charge until they are fully charged (it will take several hours to charge a 10,000 mAh D cell and the voltage when charged will be above 1.4 V). Once they are charged run them until they are discharged then repeat. Expect it to take 10-100 charge/discharge cycles before they are fully vibrant.

With the eneloops the problem could be similar. When in storage for a while eneloops do tend to experience an increase in internal resistance and a voltage depression on discharge at higher rates. The cure again is to keep cycling them, or to run them through a break-in cycle on the C9000 if you have one.

NiMH cells need to be exercised to perform at their best. They do not like sitting around, and brand new cells have been sitting in a warehouse for a while.

 

[snakebite]

i wound up with 10 of these on my bench that a friend bought for a baby swing.
no runtime at all till they were cycled 7 times on my triton.
about 8 ah at 1a discharge.
further cycling didnt help much.
i suspect they were very old stock as most were at .5 v out of the box.
but they work ok for the intended use and should pay for themselves if they dont go short or leak like many of these generic cheap chinese cells often do.
and post pictures of the suspect eneloops.
they should do on average 1450 mah out of the package.if not then something is up.
real ones are very consistant and duds are very rare.whole packs that are duds would point to counterfiets.

 

[beamis]

It's possible you might be leaping to conclusions here.

Both the D cells and the Eneloops may need a few conditioning cycles before they perform at full strength. Firstly, what was the voltage on the D cells when you received them and before you charged them?

0.5 - 0.7V when I first opened them. Put them on the charger and they only charged for about 2 minutes before it said it was done. After that they read 1.37V, but as soon as a load was applied they died almost immediately. Ran them through 3 refresh cycles and now they're taking about 45 minutes to go through the whole cycle. Not impressed yet.

As far as the Eneloops, they're not Eneloops. The ink is different, the wrapper doesn't go all the way over the top of the battery like Eneloops, and the white isn't pearly white like Eneloops. Added to the fact that the date code is completely unreadable.

Secondly, note that brand new cells can be difficult to charge since they sometimes give an early termination signal and fool the charger into stopping the charge early on. What you need to do is put them on a regular charge cycle and keep putting them back on charge until they are fully charged (it will take several hours to charge a 10,000 mAh D cell and the voltage when charged will be above 1.4 V). Once they are charged run them until they are discharged then repeat. Expect it to take 10-100 charge/discharge cycles before they are fully vibrant.

With the eneloops the problem could be similar. When in storage for a while eneloops do tend to experience an increase in internal resistance and a voltage depression on discharge at higher rates. The cure again is to keep cycling them, or to run them through a break-in cycle on the C9000 if you have one.

I ran the "Eneloops" through three refresh cycles on the C9000 and they didn't improve a whole lot. They couldn't even perform as well as my Rayovac 4.0 batteries. Judging by their electrical performance AND their appearance, I'd wager a hefty sum that they aren't Eneloops. In fact, they match the appearance of the batteries in this post except the positive terminal looks like the Eneloops now. The wrapping, low quality printing, and the poor date codes are the same.

I know it takes NiMH cells a few cycles to get up to speed, but if they are so dead upon arrival that they are reading 0.5V, they shouldn't be shipping them that old. I'm willing to bet they'll never fully recover.

 

[Mr Happy]

what was the voltage on the D cells when you received them and before you charged them?

0.5 - 0.7V when I first opened them.

Yes, that's not a good sign. NiMH cells really should be reading above 1.1 - 1.2 V when you receive them. If you can't recover them to a reasonable capacity it would be appropriate to return them for exchange or refund.

 

[beamis]

Here are some pics of the counterfeit Eneloops. What surprises me the most about them is that they came from Amazon.com. Not from an Amazon.com merchant, but from Amazon.com itself. I hope they figure out what supplier is ripping them off and quickly. There are a lot of negative reviews on the Eneloop page and I suspect it's because of these counterfeit ones.

Notice that the real Eneloop is pearly white. You can see the iridescence in both the lettering and the white background. The genuine Eneloop's lettering is of an even color. The counterfeit Eneloop is just white without any iridescence, and the lettering has a slightly darker border. The letters on the counterfeit are also surrounded by a halo of a slightly lighter color (didn't come out in the photo).

The genuine Eneloop's wrapper is very tight and reaches almost halfway to the positive button. The counterfeit is thicker, has a sloppy joint, and barely curls over the top of the battery.

EDIT - I see in other threads that the wrappers of newer Eneloops does look sloppy like these. What I can't understand is the terrible performance where I only got 100 mAh out of one cell and after charging they couldn't even stay above 1.2V after 15 minutes at 1A.

 

[Mr Happy]

Here are some pics of the counterfeit Eneloops. What surprises me the most about them is that they came from Amazon.com. Not from an Amazon.com merchant, but from Amazon.com itself. I hope they figure out what supplier is ripping them off and quickly. There are a lot of negative reviews on the Eneloop page and I suspect it's because of these counterfeit ones.

Notice that the real Eneloop is pearly white. You can see the iridescence in both the lettering and the white background. The genuine Eneloop's lettering is of an even color. The counterfeit Eneloop is just white without any iridescence, and the lettering has a slightly darker border. The letters on the counterfeit are also surrounded by a halo of a slightly lighter color (didn't come out in the photo).

The genuine Eneloop's wrapper is very tight and reaches almost halfway to the positive button. The counterfeit is thicker, has a sloppy joint, and barely curls over the top of the battery.

EDIT - I see in other threads that the wrappers of newer Eneloops does look sloppy like these. What I can't understand is the terrible performance where I only got 100 mAh out of one cell and after charging they couldn't even stay above 1.2V after 15 minutes at 1A.

I do think you are being rather hasty in assuming these are counterfeit. I have some genuine Eneloops purchased in Japan and they are identical to yours (apart from the Japanese lettering). What you are seeing is what we might call the Eneloop (II) version. This has the different single color wrapper that you observe without a transparent overlay, and the eneloop logo is printed in a raised metallic blue style that reflects the light with shiny highlights.

As to their performance, you do need to give them a few charge/discharge cycles before you can assess them. Although they are preconditioned at the factory they still need at least 10 cycles before they will really sing.

 

[Gordo]

I have purchased Eneloops on two different occations from Amazon. (Three if you count the ones not here yet.) Once from Amazon and once from an Amazon merchant. All 12 are like what Mr. Happy describes. Hopefully they are the Eneloop II ver. They perform as advertised.