Eneloop capacity variance in same batch - is this normal?

[jahxman]

I have 16 Eneloop 2000mAh AA batteries that I got to feed my TK40, and a LaCrosse BC-700 charger to charge them.

One of the functions of the LaCrosse is to test the capacity of each individual cell; it does this by going through a full charge - discharge - charge cycle on the battery, and records the capacity.

Most of my cells come out as over 2000mAh but 4 of them come out at less than 1000 mAh! Is this normal?

It concerns me because I use them in the TK40, which uses two parallel banks of four cells in series, and it seems to me the chances of reverse charge will be much greater with a sprinkling of less than half capacity cells in there.

Right now I have segregated out the lower capacity cells as identified by my charger, but it means I don't have two complete sets of batteries to keep the light powered.

Anyone else have any experience with this? Would Sanyo replace the lower capacity cells for me?

 

[Mr Happy]

This is very abnormal. Most people find eneloops to be very consistent with very little test variation between cells. Also, for an AA cell to test below 1000 mAh something has to be very badly wrong somewhere, either with the cell or with the charger.

How are you charging the cells? You should be sure always to use the 700 mA charge rate on the BC-700 and never use 200 mA.

 

[VidPro]

what he said ^ if i had some 1500ma capacity AA even, i would wonder what i did to them to cause that, or what crappy clone i bought , or what i did to it on the charger. even after years of completly different uses, the wurst ones are neer ~1900 and just needed cycling.

did you do a VISUAL comparison of the wrap around the cells, and the top and bottom and say the batch date thing ?
do a visual of them at the nipple of the battery, see any white cyrystaline powder substance around the top vent holes?

 

[jahxman]

They are all pretty new, about a month old, and only have a few cycles on them.

8 I purchased from Amazon, and the other 8 I got from DX. Visually they all look ok, although there is some slight difference in the size of the printing, etc between the Amazon and DX ones.

I am running them through a refresh cycle now at 700 mA charge/ 350 mA discharge to see if they can recover.

I did use the 200 mA charging rate, maybe that's the problem? I had the impression that slower is better for the batteries, not sure where I got that from.

 

[Mr Happy]

Which are the bad ones?

Note that the DX ones should look identical to the Amazon ones in their size and physical appearance, and except for language differences the printing should look the same too.

 

[lebox97]

for eneloop charging/maint discussion see here

 

[wapkil]

Which are the bad ones?

Note that the DX ones should look identical to the Amazon ones in their size and physical appearance, and except for language differences the printing should look the same too.

IIRC there were many problems with Eneloops bought on DX that turned out to be fakes. jahxman - have you checked the discussion threads (or reviews) on DX related to the ones you bought?

 

[tabetha]

I know it's not the exact same battery but thought my input might assist.
I buy Uniross Hybrio a LSD aa battery, I too have found a huge variation with the lowest coming around 800mah, for 1st charge, but getting progressively better, after successive charges to be better than rated.
I always charge mine on the BC700 and BC900(technoline) at 200ma.
Maybe this is more particular to LSD types ?
tabetha

 

[Foxx510]

Yep as said above DX was selling fakes.

 

[Marduke]

I always charge mine on the BC700 and BC900(technoline) at 200ma.

Try using 1A instead.

 

[tabetha]

I've tried 1A, but find they seem to like a slow charge better, having more charge left after a few weeks.
tabetha

 

[Marduke]

But you have a greater chance of damaging the cell with a missed termination.

 

[yellow]

I have relatively new Eneloops and Uniross Hybrio. All AA. 16 together.
They run from 2100-2000 (real discharge value, shown after charging)

1000 or 1500?
imho cells dead or faked wraps.

 

[wapkil]

I know it's not the exact same battery but thought my input might assist.
I buy Uniross Hybrio a LSD aa battery, I too have found a huge variation with the lowest coming around 800mah, for 1st charge, but getting progressively better, after successive charges to be better than rated.

I never heard about genuine LSD cells behaving this way. Do you write here about the same Hybrios that you measured to have 2.6Ah - 3.0Ah? As people pointed out in that thread, they may be fakes, you may measure them incorrectly, overcharge them, or even all of these problems combined.

 

[TakeTheActive]

SLOW Charge Rate Is Not Always BEST Charge Rate!

...I always charge mine on the BC700 and BC900(technoline) at 200ma...

:thinking: SLOW Charge Rate Is Not Always BEST Charge Rate! ​

 

[Gazoo]

tabetha - I agree with wapkil. LSD batteries are extremely tough and do not behave the way as you have described in your posts. These days NIMH batteries are made to be charged at 1C. However I always charge my AA eneloops at .5C....1 amp. This is the default rate of my C9000 charger.

I have a set of 4 AA eneloops that had been sitting new in the package for almost 2 and a half years. I did a discharge test on all 4, straight out of the package. All four had well over 75% of their capacity left. So I am scratching my head trying to figure out why your measurements are so inconsistent. I have quite a few AA and AAA eneloops and they are very consistent while charging, discharging, and while in use.

 

[TakeTheActive]

IIRC there were many problems with Eneloops bought on DX that turned out to be fakes. jahxman - have you checked the discussion threads (or reviews) on DX related to the ones you bought?

:thumbsup:

 

[Burgess]

I agree that something is VERY wrong here !


My first guess, would be counterfeit batteries (fakes).




_

 

[jahxman]

Which are the bad ones?

Note that the DX ones should look identical to the Amazon ones in their size and physical appearance, and except for language differences the printing should look the same too.

They do look almost identical - except the size of the font on the DX ones is a little smaller, and there is a line of smudge through the writing on one side, as if they lay on a surface when the ink was wet. The packaging was also different, the DX ones were in flimsier plastic blister packs, all plastic, with Japanese characters, while the Amazon ones were in blister packs backed by cardboard, and everything was in English I think.

There were < 1 Ah cells in both the 8 I got from DX and the 8 I got from Amazon, as reported by my BC-700 after a charge test cycle at 200 mA.

I am running the DX ones through a refresh on the BC-700 now at 700 mA charging rate, and so far they all seem to be recovering to minimum 2450 mAh. Once I get done with that I'll run the Amazon ones through. Maybe this was all they needed, and the 200mA charging rate was making some of them terminate too early.

 

[Marduke]

I think you need to read up on how to use your charger as well. 2450 is much to high, and i suspect that is the charge capacity, not the discharge capacity.

Run the test mode to find the discharge capacity.