AA Battery capacity testing using Zb2l3

[skmdmasud]

Hi,
I recently bought the Zb2l3 battery tester which gives ok result for Li-On batteries. When i am testing AA NiMh batteries it is giving very unacceptable results. Example: i have almost new Energizer 2000mAh batteries, tested it and got only 400 mAh cut off voltage was .8V load resistance was 2ohms , have another brand 1200 mAh battery tester it and got 100 something mAh, then i used 2xAA batteries in series cut off voltage was 1.6v and got 88mAh which is very strange.

So i am thinking may be it's not made to test low voltage batteries although it supports it or may be i am using too high load resistor?

Any help will be appreciated.

 

[Nigel Goodwin]

Use a lower load value - capacity is severely reduced at high loads.

 

[skmdmasud]

Use a lower load value - capacity is severely reduced at high loads.

How low like 20 ohms ?

 

[Nigel Goodwin]

How low like 20 ohms ?

Try it and see what results you get.

 

[skmdmasud]

Try it and see what results you get.

I tried with 5ohms which burned around 220mAh but the result was around 600mAh no improvement. Any idea. Or is my batteries not genuine?

 

[Nigel Goodwin]

I tried with 5ohms which burned around 220mAh but the result was around 600mAh no improvement. Any idea. Or is my batteries not genuine?

Possibly not genuine?, and also quite possible that the specs are fairly imaginary. Generally the specs will be done using a VERY small load, in order to try and make the batteries look far better than they actually are.

 

[rjenkinsgb]

You could do a simple test; leave each cell connected individually with a resistor across it for a week...
Something between 2 - 10 ohms should be OK.

Then fully charge them and repeat the capacity test with eg. the 20 Ohm resistor.

It may have no effect at all - or you may find the cell capacities to show as a lot higher??

 

[Nigel Goodwin]

You could do a simple test; leave each cell connected individually with a resistor across it for a week...
Something between 2 - 10 ohms should be OK.

That sounds rather nasty

Doesn't completely draining the batteries tend to damage them?.

 

[audioguru]

Energizer has good 2300mAh AA Ni-MH cells and cheap 2000mAh ones that I have never seen. You got the cheap one, its 2000mAh is rated at 400mA with a 1V cutoff. I have used their 2300mAh cells for years with no problems.

Recently I saw that Cosco was selling a Duracell charger with four AA and four AAA Ni-MH cells for such a good price that the charger and 2 of the cells are free so I bought a few. They did not work well then I saw the fine print said Made In China, AA capacity 1400mAh. A ripoff.

 

[skmdmasud]

You could do a simple test; leave each cell connected individually with a resistor across it for a week...
Something between 2 - 10 ohms should be OK.

Then fully charge them and repeat the capacity test with eg. the 20 Ohm resistor.

It may have no effect at all - or you may find the cell capacities to show as a lot higher??

Ooh man it took 1.5 months for the tester to arrive now weeks to test batteries lol.. the batteries perform good in toys, i believed the rating on those batteries and i was happy, now i see the truth and i am curious .. i have another brand camelion aaa 1200 mAh i will put them to test and will share the result.

One thing is as per ohms law the current keeps and decreasing with V, is that making the test inaccurate should i get a CC CV circuit and connect it in between?

 

[skmdmasud]

Energizer has good 2300mAh AA Ni-MH cells and cheap 2000mAh ones that I have never seen. You got the cheap one, its 2000mAh is rated at 400mA with a 1V cutoff. I have used their 2300mAh cells for years with no problems.

Recently I saw that Cosco was selling a Duracell charger with four AA and four AAA Ni-MH cells for such a good price that the charger and 2 of the cells are free so I bought a few. They did not work well then I saw the fine print said Made In China, AA capacity 1400mAh. A ripoff.

True, my energizer battery came free with the charger, i got 4 2000mah batteries with the charger, where else if i buy only batteries a pair costs almost close to the whole package i got.

 

[audioguru]

In Google there is a Camelion battery company in Germany and another one with different looking batteries in Hong Kong.
In You Tube there are many battery tests, some are good and some are done completely wrong.
I think it is important to test the capacity of a battery with a constant current, not with a simple resistor.

 

[rjenkinsgb]

That sounds rather nasty

Doesn't completely draining the batteries tend to damage them?.

Not if it's done on individual cells, and they are not left flat for more than a few days.

If you do that with a battery - series cells - the weakest ones become reverse polarised as the others still provide current.
That's the really nasty situation and why batteries should never be discharged below 1V per cell, to ensure none ar reverse charged.


NiMH cells do show a definite memory effect if kept charged for long periods, as the plates crystallise and become less reactive - at the normal discharge depth, the internal resistance suddenly jumps and they can appear flat under load.

They can still discharge, just a lot slower.. The resistor across the cell for a few days allows for that discharge, and once it has happened the plates reform during the next charge and the cell will work at its true capacity.

I don't tend to use NiMH cells much now but when I did use them regularly I had a few AA holders with resistors fitted to allow for this. It can have a very drastic effect if the cells are otherwise OK.

 

[skmdmasud]

I started testing the camelion battery, its doing good, already crossed 300mAh and running strong at 0.

.9v. i have setup the stop V at .5

 

[audioguru]

I remember obsolete Energizer 1500mAh Ni-MH cells about 9 or 10 years ago. They are so old that today they might only barely work.

 

[skmdmasud]

After the Camelion AAA battery test (around 400mah real capacity) i came to the conclusion that all batteries that i have are either fake or replica or over rated.

I am happy that at least they work well enough in toys and other non critical devices, its better to have rechargable batteries then non rechargable batteries.

 

[audioguru]

I have many cheap Chinese solar garden lights. Old ones came with a 250mAh AA Ni-Cad cell that rusted away in a couple of months. Newer ones come with a 300mAh or 600mAh AAA Ni-MH cell that do not rust. The 300 and 600 have the same capacity of maybe only 200mAh. Most of my Energizer AA (2300mAh) and AAA (800mAh) Ni-MH cells (made in Japan) have truthful capacity.

 

[skmdmasud]

I have many cheap Chinese solar garden lights. Old ones came with a 250mAh AA Ni-Cad cell that rusted away in a couple of months. Newer ones come with a 300mAh or 600mAh AAA Ni-MH cell that do not rust. The 300 and 600 have the same capacity of maybe only 200mAh. Most of my Energizer AA (2300mAh) and AAA (800mAh) Ni-MH cells (made in Japan) have truthful capacity.

My quest is not over, i will try to find original made in japan energizer cell for my satisfaction.

 

[skmdmasud]

Update: finally got my new tester TEC-06, tested the 1500mah battery and got 1460. Did some more tests and everything looks as expected. The ZB2l3 is not accurate.

 

[audioguru]

All the Energizer Ni-MH cells made recently are made in Japan and hold a charge for one year. Maybe they use the Sanyo/Panasonic Eneloop chemistry.
Costco sells a Duracell charger that comes with 4 AA Ni-MH and 4 AAA cells (only 1300mAh for the AA cells). They are made in China.