Ansmann maxE D 8500 mAh capacity check

This is the start of a 6 month test for Ansmann maxE D 8500 mAh.

This exercise is to find out capacity out of retail package, after each forming charge and what remains after 6 months. This will also show benefit (or not) when forming charge is performed back to back.

Advertised capacity is 8,500 mAh. I did not see any production dates or lot numbers printed on battery label so I don't know how long these batteries have been out on retail shelves. These batteries were purchased May, 2011.

Procedure as follows:
1. Discharge at 1.7A (.2C) until 0.9V.
2. Charge at .9A (.1C rounded up), until 13,600mAh (1.6C).
3. Steps 1 and 2 above is repeated 4 times with 1 hour pause in between.
4. After last charge, battery is stored for 6 months then discharge at 1.7A (.2C).

Other notes:
a. Discharge 1 is capacity available out of retail package.
b. Discharge 2, 3 and 4 is capacity after each forming charge.
c. Discharge 5, to be done six months later, will be capacity remaining to verify LSD.
d. Equipment used is BC8DP with its corresponding software for logging.

Summary of time and capacity in mAh (% of 8500) to reach certain voltage below.

Battery A
# + 1.20V ------------ + 1.10V --------------- + 1.00V --------------- + End ------------------
1 | 00:00 000 ( 0.00%) | 2:20:38 3984 (46.87%) | 3:48:57 6486 (76.31%) | 4:03:46 6904 ( 81.22%)
2 | 27:43 783 ( 9.21%) | 3:53:06 6600 (77.65%) | 4:51:01 8240 (96.94%) | 5:02:50 8574 (100.87%)
3 | 29:48 842 ( 9.91%) | 4:00:12 6801 (80.01%) | 4:52:59 8296 (97.60%) | 5:04:13 8611 (101.31%)
4 | 30:53 871 (10.25%) | 4:03:24 6890 (81.06%) | 4:53:52 8320 (97.88%) | 5:04:28 8617 (101.38%)

Battery B
# + 1.20V ------------ + 1.10V --------------- + 1.00V --------------- + End ------------------
1 | 00:00 000 ( 0.00%) | 1:23:48 2371 (27.89%) | 3:42:10 6289 (73.99%) | 4:02:16 6857 ( 80.67%)
2 | 23:48 672 ( 7.91%) | 3:24:47 5797 (68.20%) | 4:39:15 7906 (93.01%) | 4:54:37 8339 ( 98.11%)
3 | 25:30 719 ( 8.46%) | 3:32:24 6012 (70.73%) | 4:41:10 7960 (93.65%) | 4:55:20 8359 ( 98.34%)
4 | 26:36 751 ( 8.84%) | 3:36:36 6131 (72.13%) | 4:41:14 7962 (93.67%) | 4:54:55 8348 ( 98.21%)

Battery C
# + 1.20V ------------ + 1.10V --------------- + 1.00V --------------- + End ------------------
1 | 00:00 000 ( 0.00%) | 2:25:31 4118 (48.45%) | 3:59:43 6786 (79.84%) | 4:14:58 7216 ( 84.89%)
2 | 27:47 784 ( 9.22%) | 3:55:48 6676 (78.54%) | 4:55:25 8365 (98.41%) | 5:07:58 8718 (102.56%)
3 | 30:13 853 (10.04%) | 4:02:19 6861 (80.72%) | 4:56:49 8404 (98.87%) | 5:08:43 8739 (102.81%)
4 | 31:52 900 (10.59%) | 4:06:24 6976 (82.07%) | 4:58:03 8439 (99.28%) | 5:09:13 8754 (102.99%)

Battery D
# + 1.20V ------------ + 1.10V --------------- + 1.00V --------------- + End ------------------
1 | 00:00 000 ( 0.00%) | 1:36:21 2730 (32.12%) | 3:46:28 6415 (75.47%) | 4:04:33 6925 ( 81.47%)
2 | 22:25 632 ( 7.44%) | 3:25:04 5805 (68.29%) | 4:40:03 7929 (93.28%) | 4:54:30 8336 ( 98.07%)
3 | 24:47 698 ( 8.21%) | 3:31:59 6000 (70.59%) | 4:40:43 7947 (93.49%) | 4:54:43 8340 ( 98.12%)
4 | 26:14 740 ( 8.71%) | 3:37:44 6163 (72.51%) | 4:42:03 7985 (93.94%) | 4:54:55 8348 ( 98.21%)

Summary of discharge curve #1 and average of #2, #3 and #4 for each battery.




Battery A details






Battery B details






Battery C details






Battery D details

Hello My2Cents,

Interesting results.

While the capacity is in line with the rated capacity of the cell, the voltage during discharge seems low.

If you scroll down to the AccuPower D cells in this thread, you will notice that under about a 0.2C load (2 amps) the voltage remained above 1.2 volts.

NiMh cells are generally rated at 1.2 volts, but it looks like your cells would be rated closer to 1.15 volts.

It will be interesting to see how they do in 6 months.

Tom

Yes indeed. It will be interesting to see if other size-D LSDs will have the same pattern. I have Tenergy, NexCell, Imedion and AccuEvolution lined up. What caught my attention here is this brand have 2 year warranty while the others only have 1 year or 6 months. Test rig is all set, so result should be out every 2 weeks.

Capacity remaining after 6 months below.
Included min/max thermometer shows range of 15-26 degrees celsius while in storage.

# + 1.20V ----------- + 1.10V --------------- + 1.00V --------------- + End -----------------
A | 00:06 001 (0.01%) | 2:20:06 3966 (46.66%) | 4:01:08 6828 (80.33%) | 4:18:34 7323 (86.15%)
B | 00:07 001 (0.01%) | 2:11:36 3725 (43.82%) | 3:52:04 6571 (77.31%) | 4:09:25 7064 (83.11%)
C | 00:10 001 (0.01%) | 2:31:49 4297 (50.55%) | 4:05:22 6946 (81.72%) | 4:21:45 7413 (87.21%)
D | 00:00 000 (0.00%) | 2:04:50 3537 (41.61%) | 3:53:47 6622 (77.91%) | 4:11:14 7116 (83.72%)