Tests and reviews of different batteries to help you find the Right One…
The 8.4V 200 mAh Uniross NiMH batteries we are testing here are traditional rechargeable NiMHs and though they are labeled as 9V, they are consist essentially of 7 NiMH cells of 1.2V each, so they are more like 8.4V and not the same as 9V alkaline, but some battery manufacturers prefer to label their 8.4V NiMH products as 9V for the the consumer to easily associate them as a rechargeable alternative to the 9V Alkaline batteries and Uniross is apparently one of those battery makers.
In order to test the capacity of the 8.4V 200 mAh Uniross NiMH batteries we are using a constant current discharge rate of 0.05A (50 miliampers) and we have managed to get 217 mAh and that is a bit over the rating of these batteries, so it seems that Uniross has done a good job with these. The only drawback is that the capacity of the battery is a bit on the lower end of the capacity offered by 8.4V products and that along with the fact that this is not an LSD battery makes is a bit of a problem if you want to get longer operation time when using this battery in a low power device.
The performance of the 8.4V 200 mAh Uniross NiMH Batteries in our tests:
– 217 mAh at 0.05A load
– 1.887 Wh at 0.05A load
The 8.4V 280 mAh Fujicell NiMH batteries we are testing here are from the traditional type of rechargeable Nickel Metal Hydride batteries and they come with a pretty high capacity for their type of 280 mAh, so we would be interested to see if they can actually deliver it. Fujicell rates these batteries as being capable of being recharged up to 1000 times, so they should be able to serve you for pretty long time considering that this type of batteries is often used for low power applications.
In order to test the capacity of the 8.4V 280 mAh Fujicell NiMH batteries we are using a constant current discharge rate of 0.05A (50 miliampers) and we have managed to get 285 mAh capacity before hitting the 7V cutoff voltage and that is actually a bit over manufacturer’s rating for this battery that is 280 mAh. So we cans ay that with this battery Fujicell has done a good job and they manage to deliver what they have promised as capacity, now if only the battery was also a low self discharge type NiMH, but nevertheless a good product from Fujicell.
The performance of the 8.4V 280 mAh Fujicell NiMH Batteries in our tests:
– 285 mAh at 0.05A load
– 2.486 Wh at 0.05A 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.