Battery test information

What are the best batteries??

How do batteries compare??

The first column displays test results from battery analyzer tests. This device allows testing at selected current load. Time, Voltage and Current are logged. Results are  battery discharged capacity (mAh) and discharged energy (mWh). For all NiMH cells the test termination voltage is 0.90V. The test current for AAA and AA cells is 500 mA. Test current for C and D cells is specified in the test results. This allows comparison of the cells with no other factors influencing the results as may be the case in the testing charger results. This can be compared to the results from the individual charger tests to see how the chargers perform. Note: only the BT-C2400BT-C2000, BT-C700 and BM200 are capable of testing the C and D cells with adapters. The BT-C3400 is capable of up to C size natively and D cell with adapter. This is due to firmware restrictions in the other chargers. The C9000 firmware will allow testing of high capacity cells up to 19.9 Ah however contact resistance issues prevent reliable results with C & D battery adapters in some chargers. Custom test adapters were used for C9000 C & D cell testing to minimize contact resistance in that charger.

I use the chargers available with a test function. This function displays the actual capacity of the cells under test. All of the chargers perform this test basically the same way. First the test parameters are set. Then the test cycle begins. The cells are charged to full using a -dV algorithm to detect full charge. Then the cells are discharged at the test rate while timing the discharge. When a predetermined voltage is reached (0.9V) then discharge is terminated. Then the cells are charged again. At the end of test cycle the capacity measured during the discharge is displayed.

All cells are retail new and are run through 2 recondition cycle before capacity testing is performed. In all tests 4 cells are tested and results averaged. Please note that due to variations in manufacturing and testing any results within several percent of value should be considered identical for these tests. This chart will grow as I get more batteries to test. Enjoy the results.

Note; the BC-9009 and BC-1000 are identical except for the color of the case. Both have same circuit board revision and firmware revision. BC-9009 is no longer avaialble new.

Batteries are ranked from results of the Battery Analyzer tests.

AA Cells


Battery Brand and Type
Battery Analyzer
Discharged Capacity
Test Results
MH-C9000
Test Results
BC-700
Test Results
IQ328
Test Results
BC-9009
/BC-1000
Test Results
BT-C2000
BT-C2400
Test Results
BT-C700
Test Results
PowerEx AA 2700
2565 mAh 2420 mAh
2690 mAh
2610 mAh
2660 mAh
2451 mAh 2504 mAh
2574 mAh
Eneloop XX AA (LSD) 2475 mAh 2420 mAh 2510 mAh 2520 mAh 2610 mAh 2430 mAh 2466 mAh
2642 mAh
AccuPower AA 2900
2426 mAh 2359 mAh 2675 mAh 2522 mAh 2515 mAh 2447 mAh 2448 mAh
2516 mAh
Tenergy Premium AA 2500
2374 mAh 2367 mAh 2520 mAh 2457 mAh 2507 mAh 2365 mAh 2388 mAh
2356 mAh
Duracell AA 2550
2345 mAh 2340 mAh
2440 mAh
2390 mAh
2420 mAh
2275 mAh 2315 mAh
2354 mAh
PowerEx Imdeion AA 2400 (LSD) 2344 mAh 2210 mAh 2410 mAh 2290 mAh 2310 mAh 2254 mAh 2310 mAh
2348 mAh
Ansman AA 2850
2310 mAh
2286 mAh 2515 mAh 2407 mAh 2410 mAh 2375 mAh 2395 mAh
2388 mAh
TruCELL Precharged AA (LSD)
2310 mAh 2270 mAh 2400 mAh 2330 mAh 2320 mAh 2292 mAh 2340 mAh
2322 mAh
AccuPower AccuLoop AA 2300 (LSD)
2285 mAh 2235 mAh 2342 mAh 2240 mAh 2312 mAh 2268 mAh 2246 mAh
2281 mAh
Energizer Rechargeable AA 2300 (LSD)
2244 mAh 2220 mAh 2347 mAh 2292 mAh 2315 mAh 2191 mAh 2210 mAh
2298 mAh
Delkin Devices AA 2900 
2175 mAh 2192 mAh 2385 mAh 2330 mAh 2302 mAh 2197 mAh 2232 mAh
2298 mAh
La Crosse AA 2600 2130 mAh 2070 mAh 2460 mAh 2190 mAh 2150 mAh 2144 mAh 2124 mAh
2210 mAh
Amazon Basics AA 2000 (LSD)
2125 mAh 2112 mAh 2295 mAh 2237 mAh 2217 mAh 2151 mAh 2166 mAh
2206 mAh
Tenergy Centura AA 2000 (LSD)
2021 mAh 2008 mAh 2122 mAh 2085 mAh 2090 mAh 1946 mAh 2088 mAh
2034 mAh
Rayovac Platinum AA (LSD) 1997 mAh 2010 mAh 2090 mAh 2010 mAh 2100 mAh 1986 mAh 2008 mAh
2084 mAh
Eneloop AA White (LSD) 1975 mAh 1940 mAh 2100 Ah 2060 mAh 2110 mAh 1998 mAh 1988 mAh
2022 mAh
Tenergy (Blue) AA 2600
1970 mAh 1990 mAh
2140 mAh
2000 mAh
2040 mAh
1892 mAh 1980 mAh
1986 mAh
CFL AA 3800
642 mAh 639 mAh 672 mAh 677 mAh 666 mAh 641 mAh 652 mAh
652 mAh
BTY AA 3000
476 mAh
459 mAh
575 mAh
548 mAh
537 mAh
499 mAh 498 mAh
488 mAh
Ultrafire AA 3500
424 mAh
367 mAh
465 mAh
463 mAh
423 mAh
429 mAh
434 mAh
414 mAh

AAA Cells


Battery Brand and Type Battery Analyzer
Discharged Capacity
Test Results
MH-C9000
Test Results
BC-700
Test Results
IQ328
Test Results
BC-9009/
BC-1000
Test Results
BT-C2000
BT-C2400
Test Results
BT-C700
Test Results
AccuPower AAA 1200
988 mAh
1006 mAh
1007 mAh
1034 mAh
971 mAh
973 mAh 970 mAh

PowerEx AAA 1000 982 mAh 981 mAh 1026 mAh 984 mAh 1004 mAh 978 mAh 988 mAh

PowerEx Imedion AAA 950 (LSD) 927 mAh 907 mAh 1019 mAh 970 mAh 971 mAh 899 mAh 908 mAh

Duracell AAA 1000 919 mAh 934 mAh 1017 mAh 973 mAh 1026 mAh 918 mAh 936 mAh

Eneloop XX AAA 950 (LSD)
880 mAh 907 mAh 987 mAh 930 mAh 957 mAh 936 mAh926 mAh

Tenergy Premium AAA 1000
877 mAh 854 mAh 900 mAh 890 mAh 906 mAh 855 mAh 878 mAh

Amazon Basics AAA 800 (LSD)
824 mAh 834 mAh 903 mAh 899 mAh 897 mAh 833 mAh 848 mAh

Eneloop AAA White 800 (LSD) 799 mAh 832 mAh 877 mAh 827 mAh 835 mAh 835 mAh 838 mAh

AccuPower AccuLoop AAA 950 (LSD)
789 mAh
817 mAh
842 mAh
807 mAh
812 mAh
825 mAh 822 mAh

Tenergy Centura AAA 800 (LSD)
788 mAh 774 mAh 838 mAh 774 mAh 782 mAh 781 mAh 792 mAh

Rayovac Platinum AAA (LSD) 775 mAh 773 mAh 788 mAh 806 mAh 820 mAh 774 mAh 786 mAh

Tenergy (Blue) AAA 1000 750 mAh 760 mAh 811 mAh 779 mAh 808 mAh 751 mAh 744 mAh

La Crosse AAA 1000 741 mAh 789 mAh 842 mAh 835 mAh 799 mAh 775 mAh 758 mAh



Click on the above link to purchase on ebay.

(LSD) = Low Self Discharge type, ie. Imedion, Eneloop, AccuLoop
Four cells are tested on each charger.
The average of the four tested cells for each charger is displayed.

Test settings:
Maha MH-C9000.
Charge 1000 mA
Discharge 500 mA

La Crosse BC-700.
Charge 700 mA
Discharge 350 mA

AccuPower IQ328.
Charge 1000 mA
Discharge 500 mA

La Crosse BC-9009/BC-1000
Charge 1000 mA
Discharge 500 mA

BT-C2000
BT-C2400
Charge 1000 mA
Discharge 500 mA

BT-C700
Charge 700 mA
Discharge 500 mA

BT-C3400
Charge 1000 mA
Discharge 700 mA

C Cell


Battery Brand and Type
Battery Analyzer
500 mA rate
Battery Analyzer
1000 mA rate
MH-C9000
500 mA rate
MH-C9000
1000 mA rate
BT-C2000
BT-C2400
500 mA rate
BT-C700
500 mA rate
700 mA rate
Tenergy Premium C 5000
5268 mAh
5162 mAh
5136 mAh 5126 mAh 5296 mAh
5144 mAh
5228 mAh
AccuPower C 6000
5005 mAh
4950 mAh
5174 mAh 5126 mAh 4721 mAh
4986 mAh
4988 mAh
PowerEx Imedion C 5000 (LSD)
4231 mAh
4037 mAh
4050 mAh 3938 mAh 4166 mAh
4226 mAh
4196 mAh
Tenergy Centura C 4000 (LSD)
4172 mAh
3954 mAh
3996 mAh 3848 mAh 4054 mAh
4038 mAh
4066 mAh
PowerEx C 5000
4049 mAh
3895 mAh
4372 mAh 4156 mAh 4236 mAh
4178 mAh
4216 mAh
AccuLoop C 4500 (LSD)
3890 mAh
3870 mAh
4044 mAh 3888 mAh 3996 mAh
3980 mAh
3926 mAh

D Cell


Battery Brand and Type
Battery Analyzer
500 mA rate
Battery Analyzer
1000 mA rate
MH-C9000
500 mA rate
MH-C9000
1000 mA rate
BT-C2000
BT-C2400
500 mA rate
BT-C700
500 mA rate
700 mA rate
AccuPower D 11500
 10088 mAh
9882 mAh
10290 mAh 10020 mAh 10290 mAh
10188 mAh

Tenergy Premium D 10000
9944 mAh
9544  mAh
8952 mAh 8138 mAh 10130 mAh
10080 mAh

PowerEx Imedion D 9500 (LSD)
8690 mAh
8549 mAh
8338 mAh 8187 mAh 8714 mAh
8502 mAh

AccuLoop D 10000 (LSD)
8192 mAh
8298 mAh
8324 mAh 8338 mAh 8440 mAh
8480 mAh

Tenergy Centura D 8000 (LSD)
8170 mAh
8044 mAh
8440 mAh 8282 mAh 8246 mAh
8260 mAh





Internal resistance measurement.

Batteries can be modeled as a voltage source in series with a resistance. In practical terms internal resistance gives an indication of how well a battery can supply current to a load without the cell voltage dropping. Low internal resistance means low cell voltage drop under load. High internal resistance means high cell voltage drop under load. So if you are looking for a battery that can delivery high current to the load you want a battery with low internal resistance. In this test internal resistance is measured using the DC method. A programmable current source is used as the load so that load current can be precisely controlled. Cell voltage is measured by a high accuracy bench DVM. The results give a change in cell voltage for each current load. This data is plugged into ohms law to calculate the equivalent resistance. Internal resistance in the chart below is given in mili-ohms, that is thousandths of an ohm. Lower is better.

AA Cells


Battery Brand
and Type
Internal Resistance Average
Test Current 500mA
Test Current 1000mA
Test Current 2000mA
Duracell AA 2550 46 mΩ 46 mΩ 45 mΩ 48 mΩ
Eneloop XX AA (LSD) 47 mΩ
50 mΩ 44 mΩ 48 mΩ
Energizer Rechargeable AA 2300 (LSD) 48 mΩ 52 mΩ 41 mΩ 52 mΩ
Eneloop AA White (LSD) 50 mΩ 52 mΩ 48 mΩ 49 mΩ
PowerEx AA 2700 55 mΩ 68 mΩ 49 mΩ 48 mΩ
AccuPower AccuLoop AA 2300 (LSD) 56 mΩ 64 mΩ 52 mΩ 53 mΩ
Tenergy Centura AA 2000 (LSD) 60 mΩ 66 mΩ 56 mΩ 58 mΩ
PowerEx Imdeion AA 2400 (LSD) 62 mΩ 50 mΩ 69 mΩ 66 mΩ
Tenergy Premium AA 2500 62 mΩ 68 mΩ 60 mΩ 57 mΩ
Tenergy (Blue) AA 2600 66 mΩ 56 mΩ 73 mΩ 69 mΩ
truCELL Precharged AA (LSD) 68 mΩ 78 mΩ 65 mΩ 61 mΩ
AccuPower AA 2900 71 mΩ 72 mΩ 69 mΩ 71 mΩ
La Crosse AA 2600 74 mΩ 90 mΩ 68 mΩ 63 mΩ
Amazon Basics AA 2000 (LSD) 81 mΩ 82 mΩ 94 mΩ 68 mΩ
Rayovac Platinum AA (LSD) 86 mΩ 82 mΩ 87 mΩ 90 mΩ
Delkin Devices AA 2900
97 mΩ 98 mΩ 94 mΩ 100 mΩ
Ansman AA 2850
105 mΩ 98 mΩ 111 mΩ 106 mΩ
CFL AA 3800
115 mΩ 125 mΩ 110 mΩ 109 mΩ
BTY AA 3000
119 mΩ 140 mΩ 114 mΩ 105 mΩ
Ultrafire AA 3500
139 mΩ 152 mΩ 132 mΩ 133 mΩ


AAA Cells


Eneloop XX AAA 950 (LSD) 68 mΩ 65 mΩ 69 mΩ 71 mΩ
AccuPower AAA 1200 71 mΩ 72 mΩ 69 mΩ 71 mΩ
Duracell AAA 1000 84 mΩ 80 mΩ 87 mΩ 84 mΩ
PowerEx AAA 1000 86 mΩ 80 mΩ 98 mΩ 81 mΩ
Tenergy Premium AAA 1000 86 mΩ 88 mΩ 87 mΩ 84 mΩ
PowerEx Imedion AAA 950 (LSD) 96 mΩ 108 mΩ 87 mΩ 92 mΩ
Eneloop AAA White (LSD) 96 mΩ 98 mΩ 101 mΩ 90 mΩ
Rayovac Platinum AAA (LSD) 98 mΩ 99 mΩ 102 mΩ 94 mΩ
Tenergy (Blue) AAA 1000 104 mΩ 104 mΩ 115 mΩ 92 mΩ
AccuPower AccuLoop AAA 950 (LSD) 113 mΩ 106 mΩ 126 mΩ 106 mΩ
Tenergy Centura AAA 800 (LSD) 113 mΩ 122 mΩ 113 mΩ 103 mΩ
Amazon Basics AAA 800 (LSD) 126 mΩ 124 mΩ 111 mΩ 143 mΩ
La Crosse AAA 1000 141 mΩ 152 mΩ 140 mΩ 131 mΩ


C Cells


Battery Brand and Type
Average
500 mA
1000 mA
2000 mA
3000 mA
Tenergy Premium C 5000 18 mΩ 18 mΩ 18 mΩ 18 mΩ 19 mΩ
Tenergy Centura C 4000 (LSD) 24 mΩ 34 mΩ 13 mΩ 24 mΩ 24 mΩ
AccuLoop C 4500 (LSD)
25 mΩ 24 mΩ 26 mΩ 26 mΩ 23 mΩ
AccuPower C AP6000
27 mΩ 32 mΩ 28 mΩ 25 mΩ 24 mΩ
PowerEx C 5000
28 mΩ 20 mΩ 42 mΩ 27 mΩ 26 mΩ
PowerEx Imedion C 5000 (LSD)
55 mΩ 80 mΩ 40 mΩ 42 mΩ 60 mΩ


D Cells

Tenergy Centura D 8000 (LSD) 15 mΩ 12 mΩ 14 mΩ 15 mΩ 17 mΩ
Tenergy Premium D 10000
17 mΩ 20 mΩ 15 mΩ 16 mΩ 16 mΩ
AccuLoop D 10000 (LSD) 19 mΩ 30 mΩ 15 mΩ 16 mΩ 15 mΩ
AccuPower D 11500
20 mΩ 28 mΩ 14 mΩ 22 mΩ 16 mΩ
PowerEx Imedion D 9500 (LSD)
33 mΩ 44 mΩ 28 mΩ 25 mΩ 37 mΩ


So what does it mean??
Example: If the internal resistance is 50 mΩ and you need to drive a load of 1 A and assume a no load cell voltage of 1.25V then under that load cell voltage would drop to 1.20V.
If you need to drive a 2A load then the cell voltage would drop to 1.15V.
If the internal resistance is 100 mΩ at 1A load then cell voltage would drop to 1.15V. Under 2A load it would drop to 1.05V.
So in the case of battery internal resistance smaller is better.

Of course the C and D cells performed the best.
All of the AA batteries seem to range form fair to good in terms of internal resistance.
The AAA batteries did not test as well but of course they have far less electrode surface area. However most put up a respectable performance.

Note: Only the BT-C3400BT-C2000, BT-C2400, BT-C700 and BM200 charger has internal resistance measurement function.