Batteries / Battery Disposable Rechargeable AA and AAA

Electronics & Technology
1

Hi,

We’ve all been using the AA and AAA batteries forever in all electronic things.
The main site has this info:



I’ve always tried to do my own research by reading but unfortunately those can be biased with no way of us knowing the level of bias.
Brand and models of batteries change, additionally many are not available easily.

What I wanted to do is try and figure a common test so its possible to compare rechargeable and disposable batteries against each other and figure out the best value for money.

There will be two categories , one for AA and another for AAA. Then also high and normal usage ( or discharge ) sub categories.

I need to get a consensus on what people believe those 4 categories should be.
Testing procedure for Choice is here

What do people think is important and any suggestion with the idea that disposable and rechargeable batteries are interchangeable and are to be used in the same device.

Basically , what do you think the cut off voltage should be and what discharge currents?
I won’t do the number of cycles a rechargeable battery can be used, that takes too much time, and will use that data from the CHOICE results.

Fire Away!

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Place holder for final test method / procedure …
This will probably be limited to equipment I have or can easily get.

CHOICE method

Disposable
End test at 0.7 Volts and 1.0Volts
Low discharge test using load of 24 Ohms
High discharge test using load of 2 Ohms
These usually have a fresh battery Voltage of around 1.5V

Rechargeable ( tested multiple times and recharged after each test )
End test at 1.05V, 1.09V, 1.14V, 1.02V, 1.09V … ? range 0.66V to 1.19V … ?
AA tested with a 10 Ohm load
AAA tested with a 24 Ohm load
These usually have a fresh battery Voltage of around 1.25V

Dr. Google says
Alakline batteries with no load …
1.3V+ are still usable.
1.2V - 1.3V okay
under 1.2V dead
Generally once the Voltage drops bellow 1.0V they are considered dead with negligible usable capacity.
Saying that, they are still capable of powering very light load devices ( ie quartz wall clock ) for a few more months.
Alkaline batteries drop Voltage as the load increases because of higher internal resistance
( this means energy is wasted on heating up the battery ).
With a very light load their capacity is huge. With heavy load the capacity is very small.
Carbon batteries are worse at this and Lithiums are better.

NiMh batteries …
hold their Voltage much better under various loads at around 1.2V - 1.3V.
when their Voltage starts to drop to around 1.1V they are almost dead.
1.0V is also considered dead with negligible usable capacity.

Generally, standard working Voltage of batteries is around 1.2 - 1.3V,
under 1.0V is considered an exhausted battery for both types.
Depending on the equipment used, the battery can be used to lower Voltages,
but almost all of its capacity would have gone under 1.0V
CHOICE results for disposable batteries show there is a rough difference of about 20%
between 1.0V and 0.7V, indicating there is still about 20% - 25% useful capacity between 0.7V and 1.0V.

3

Everyone should have a battery test meter in the home.

4

Yes, everyone should own a battery test meter ! :slight_smile:

Since all I want to do is compare the rechargeable to alkaline batteries,
I’ll get Coles and Aldi branded batteries and run the same test on all of them.
That will give us results that can be interpolated to the CHOICE results.

This way its not going to go over the top :slight_smile:

5

I have a MAHA Powerex MH-C9000 Battery
charger / analyser
http://www.protog.com.au/maha-powerex-mh-c9000-wizardone-aa-aaa-battery-cha/9000

and a
Computerized Battery Analyzer ( CBA ) model 2 from west mountain radio ( about 10 years old )
http://www.westmountainradio.com/cba.php#aboutcba

Both are capable of being programmed for a constant current discharge instead of a resistive load.

I am thinking to use a load of 24 Ohms and 2 Ohms for both alkaline and rechargeable batteries.
As I can only use constant current instead of resistive load, I need to change resistance to something
approximating this load…

Consider 1.2V per cell average for useful working Voltage …
24 Ohms represents a load of ( 1.2V / 24 Ohms ) 50 mA
2 Ohms represents a load of ( 1.2V / 2 Ohms ) 600 mA

Powerex MH-C9000 can be set up for discharge from 100mA to 1A in 0.1A increments.
CBA II , I am not sure of specs, last time used was about 10 years ago. The software also needs Windows XP …

… May have to use 100mA as minimum discharge rate ( representing 12 Ohm load ) …
Will need to check if I can get CBA II running .
Powerex MH-C9000 also has a set discharge termination at 0.9V …

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Did tests on 4 of each Aldi and Coles Rechargeable batteries and
Aldi and Coles Alkaline batteries.

Used MAHA Powerex MH-C9000 Battery charger / analyser ( uncalibrated / unverified accuracy … )
Low discharge set at 100 mAh ,
High discharge set at 600 mAh,
cut of voltage / end of test at 0.9V

Coles Rechargeable batteries @$1.75 each
100mAh rate 2336 , 2241, 2244, 2269 . ave 2,273 mAh
600mAh rate 2246, 2201, 2193, 2198 . ave 2,210 mAh
Choice results
Voltage at end of test cycle (V) 1.05
Measured capacity (mAh) 2291
Claimed capacity (mAh) 2200

Aldi Rechargeable batteries @ $1.75 each
100mAh rate 2251, 2264, 2170, 2226 . ave 2,228 mAh
600mAh rate 2255, 2155, 2251, 2195 . ave 2,214 mAh
Choice results
Voltage at end of test cycle (V) 1.02
Measured capacity (mAh) 2244
Claimed capacity (mAh) 2400

Coles Alkaline batteries @ $0.55 each BN 08-2022 ( Best Before AUG.2022 )
100mAh 1819, 1886, 1875, 1813 . ave 1,848 mAh
600mAh 1221, 1352, 1309, 1202 . ave 1,271 mAh
Choice results
Capacity at 1V (low drain) (mAH) 2514
Capacity at 07V (low drain) (mAH) 3038
Capacity at 1V (high drain) (mAH) 1683
Capacity at 07V (high drain) (mAH) 2127

Aldi Alkaline batteries @ $0.55 each BN 05-2022 UPP ( Best Before MAY.2022 ??? )
100mAh 1800, 1798, 1840, 1814 . ave 1,813 mAh
600mAh 1349, 1529, 1447, 1277 . ave 1,401 mAh
Choice results
Capacity at 1V (low drain) (mAH) 2603
Capacity at 07V (low drain) (mAH) 3129
Capacity at 1V (high drain) (mAH) 1718
Capacity at 07V (high drain) (mAH) 2111

Energizer Ultimate Lithium @ $4.50 each
100mAh 3167, 3155, 3407, 3403 . ave 3,283 mAh ( 1st 2 batteries BN 1114, 2nd 2 BN 0716 )
600mAh 3057, 3007, 3334, 3274 . ave 3,168 mAh ( 1st 2 batteries BN 1114, 2nd 2 BN 0716 )
Choice results
Capacity at 1V (low drain) (mAH) 3142
Capacity at 07V (low drain) (mAH) 3158
Capacity at 1V (high drain) (mAH) 3116
Capacity at 07V (high drain) (mAH) 3146

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Tooooo many numbers …

Results for rechargeable batteries are “close enough” between my test and Choice.
Alkaline battery results are a bit more different.
I am hoping that my tests were at least done in the same way across the 4 batteries …
( I’ve repeated the tests on one battery of each type at the same time, the results were similar to above )
I did notice that the voltage on the alkaline batteries jumped back up to around 1.3V after the test was finished.

Conclusion?
Rechargeable batteries had higher capacities under low and high load tests.
Rechargeable batteries had “much” better capacity under heavier load / higher discharge.
I am surprised that the Alkaline batteries had such low capacity in my tests :confused:
With the low self discharge of rechargeable batteries,
I think I will try them in Quartz Wall clocks and IR remote controls next time I need to change the batteries…

I tested the Lithiums, results comparable to Choices results. Still leaves Alkaline discrepancy…

Any other questions, comments, observations?

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8

Thanks for the info @Zeddy, interesting to see your results. I’ll be sure to share this info with our product testers.

9

Thanks Brendan!

Doing the test on the Energizer Lithiums, will update results.

Re Alkalines, I understand the cut off voltages are different but it still doesn’t make sense.
My cut off voltage is 0.9 V but the result is still lower that even Choices 1V cut off …
I bought the batteries within the last few weeks, so they should be fresh ( latest batch ) …

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I’ve done the 100mAh discharge test on the Lithiums, they seem fine and inline with Choice results ( considering the different batch numbers ).
Noted the Batch Numbers from the Alkalines, looks like the Coles and Aldi batteries come from the same factory …
( the batch number is in the same position, same style )

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