Posts Tagged ‘Powerex Imedion battery


The 1.2V AAA 950 mAh Powerex Imedion Rechargeable NiMH batteries are rechargeable batteries of the LSD type (Low Self Discharge) that are rated to retain up to 85% of their charge after 1 year of storage, unlike traditional NiMH batteries that will probably be completely discharged when stored for such a long period of time. The initial discharge capacity we got from these batteries was between 706 and 714 mAh with a low discharge current. Powerex is a brand of Maha Energy Corporation and is a well known brand among professional photographers for good quality batteries that are usually rated among the best and the same goes about the range of battery chargers that the company also makes. In fact we are using a MAHA Powerex C-9000 WizardOne Charger Analyzer as a part of our battery testing setup as we consider this to be one of the best AA/AAA battery chargers out there, so we do have very high expectations from these batteries.


We have started the test of the 1.2V AAA 950 mAh Powerex Imedion Rechargeable NiMH batteries as we normally do with a low constant current discharge rate of 0.1A and the result we got was 1062 mAh, or with a bit more than 100 mAh than the rated capacity. The great performance continues even after increasing the load all the way up to 1.0A where we still get 800 mAh as a useable capacity. As we expected the 1.2V AAA 950 mAh Powerex Imedion Rechargeable NiMH batteries do perform great by providing higher capacity than they are rated at and they manage to handle well in both low and high load applications.

The performance of the 1.2V AAA 950 mAh Powerex Imedion Rechargeable NiMH Batteries in our tests:

– 1062 mAh at 0.1A load
– 988 mAh at 0.2A load
– 877 mAh at 0.5A load
– 800 mAh at 1.0A load

– 1.325 Wh at 0.1A load
– 1.222 Wh at 0.2A load
– 1.057 Wh at 0.5A load
– 0.910 Wh at 1.0A load


The 8.4V 250 mAh Powerex Imedion NiMH batteries we test here are based on the new LSD NiMH type (low self discharge) and are supposed to retain up to 85% of their capacity after an year of storage unlike traditional NiMHs that discharge at a much faster rate when not being used. The best thing about LSD NiMH batteries is that they are ready to be used immediately after you get them, thanks to the low self discharge, though they are not going to offer their full capacity initially. These particular batteries are supposed to offer up to 1000 recharge cycles according to the manufacturer and though they are rated at 250 mAh they ar also supposed to provide minimum guaranteed 230 mAh capacity according to their specs.


In order to test the capacity of the 8.4V 250 mAh Powerex Imedion NiMH batteries we are using a constant current discharge rate of 0.05A (50 miliampers), but before measuring the real full capacity we measure the capacity available for use right out of the box. In the case of our test battery it was just 119 mAh or about half of the capacity of the battery, however we are not sure how long since it has been produced, though it is most likely more than a year. The 8.4V 250 mAh Powerex Imedion NiMH battery we tested here managed to provide 234 mAh capacity before hitting the 7V cutoff voltage and that is actually a bit over the minimum rating for the battery, though not that close the maximum of 250 mAh. Though in a few more cycles the battery might reach it’s full capacity as we are testing all LSD NiMH batteries after doing only one discharge/charge cycle and traditional NiMHs after a charge/discharge/charge.

The performance of the 8.4V 250 mAh Powerex Imedion NiMH Batteries in our tests:

– 234 mAh at 0.05A load

– 2.034 Wh at 0.05A load

In overall we are getting very good performance for an 8.4V NiMH battery, though some 9V Alkaline (not Carbon Zinc) batteries might be able to provide a bit higher useable capacity don’t forget that here you get a rechargeable battery with up to a 1000 recharge cycles.