Duraloops testing at 2090 mAh?

[JazzMan]

I found many packs of what I thought were Duraloops while shopping locally. White tops, slightly squared-off post, label wrapping around the bottom... looks just like what I've seen in photos on threads in this forum. So I bought a bunch.

With Eneloops having a stated capacity of 2000 mAh, I expected these Duraloops to test at 1900-2000 mAh in my La Crosse BC-9009's "test" mode. However, after running multiple tests, I've found the average capacity to be 2090 mAH (lowest cell was 2020, highest was 2140).

This leads me to question whether these are really Duraloops, because the capacity is more in line with that of Rayovac Hybrids. I have never had a test result in a greater-than-listed capacity before this. This is also the first time I have tested LSD cells though, in case they test differently.

So, what do you think? Duraloops or no?

Thanks!

 

[R@ndom]

Look at the package, made in Japan or China?

 

[JazzMan]

Look at the package, made in Japan or China?

Whoops, forgot that part! All packages and cells state "Made in Japan".

 

[TorchBoy]

I've had a single Eneloop that testing at exactly 2100 mAh on my MH-C9000, which gives more conservative capacity figures than the BC-900.

 

[Marduke]

Eneloops (and hence Duraloops) are 2000 min, 2100 typical. Eneloops IIRC are marked as such.

Edit:
Correction, 2000typ, 1900 min, but 2100 does not surprise me, my duraloops do similar.

 

[Bones]

I found many packs of what I thought were Duraloops while shopping locally. White tops, slightly squared-off post, label wrapping around the bottom... looks just like what I've seen in photos on threads in this forum. So I bought a bunch.

With Eneloops having a stated capacity of 2000 mAh, I expected these Duraloops to test at 1900-2000 mAh in my La Crosse BC-9009's "test" mode. However, after running multiple tests, I've found the average capacity to be 2090 mAH (lowest cell was 2020, highest was 2140).

This leads me to question whether these are really Duraloops, because the capacity is more in line with that of Rayovac Hybrids. I have never had a test result in a greater-than-listed capacity before this. This is also the first time I have tested LSD cells though, in case they test differently.

So, what do you think? Duraloops or no?

Thanks!

According to a very reputable source, the BC-900 tends to over-rate capacity, so there is strong liklihood that you have the real thing since all the other indicators seem to be correct.

From William Chueu of MahaEnergy:

...

6) Capacity difference between the MH-C9000 and BC-900

BC-900, according to our measurement, tends to overestimate the capacity quite a bit (for instance, the Powerex 2700mAh capacity (1A charge/discharge) typically gets 2750mAh on the BC-900, when our laboratory-grade instrument consistently give about 2550mAh). This has to do with two things: 1) accuracy of the discharge current measurement, and 2) accuracy of the time base. The MH-C9000 has a 1% tolerance in the discharge current measurement. Furthermore, the MH-C9000 uses a quartz oscilattor time base (you can see them if you open the charger, I think there are some photos here on CPF) whereas the BC-900 uses a resistor-capacitor (RC) network as a time base which is less accurate.

I trust the BREAK-IN capacity on the MH-C9000. It typically is within 2% of the capacity measured on a calibrated battery analyzer.

I hope this answers some of the questions raised.

William

If you would like even firmer assurances, you can also post some images for inspection by others who own the genuine cell. Be sure to include several different views.

 

[TorchBoy]

Eneloops (and hence Duraloops) are 2000 min, 2100 typical. Eneloops IIRC are marked as such.

They are marked "Typ.2,000mAh Min.1,900mAh".

 

[jayflash]

Yes, my BC-900 slightly over rates capacity, probably because the freshly charged cell isn't rested. I test capacity, at different rates, about a week after charging and the Japanese Duraloops and ROV Hybrids are all close to stated capacity - even at .5C - 1C discharge rates. Out of 50, 1 - 2 year old cells, they are all very close. That is impressive!