Posts Tagged ‘NiMH battery

1-2v-aa-2700-mah-sanyo-nimh-battery

The 1.2V AA 2700 mAh Sanyo Superlattice Alloy EVO NiMH batteries (model HR-3U) we test here are from the traditional NiMH type and not the newer Low Self Discharge (LSD) NiMHs even though Sanyo is also making LSD batteries and is considered as one of the top names for Rechargeable batteries. The NiMH batteries from Sanyo we are testing here are rated as 2700 mAh (that is the typical capacity and 2500 mAh minimum) and that is one of the highest capacity NiMH batteries on the market currently available. What we are expecting from these Sanyo NiMH batteries is to actually provide the said capacity and not behave like some unknown brands making batteries that are marked with very high capacities of over 3000 mAh, but hardly capable of delivering even half of that capacity. What is the most interesting thing here for these Sanyo NiMH batteries, besides their high capacity, is that they are rated as capable of handing very high loads such as 2C (two times their capacity or 5.4A) while till providing very good capacity.


1-2v-aa-2700-mah-sanyo-nimh-battery-capacity

We started the tests of the 1.2V AA 2700 mAh Sanyo Superlattice Alloy EVO NiMH batteries with a constant current discharge rate of 0.2A and they were able to provide us with 2527 mAh or a bit over the minimum rated capacity, and at a lower discharge rate they should be able to get closer to 2700 mAh. The important thing here is that Sanyo has a proper rating for these batteries, nothing less than what we have expected from them anyway. Furthermore these batteries are able to handle high current loads very well as you can see even at 2A constant current load they provide close to 1900 mAh capacity. So in overall the 1.2V AA 2700 mAh Sanyo Superlattice Alloy EVO NiMH are very good rechargeable batteries that are suitable equally well for use in applications requiring either low or high current load. They however excel at providing great capacity with very high loads.

The performance of the 1.2V AA 2700 mAh Sanyo NiMH Batteries in our tests:

– 2527 mAh at 0.2A load
– 2498 mAh at 0.5A load
– 2338 mAh at 1.0A load
– 1868 mAh at 2.0A load

– 3.141 Wh at 0.2A load
– 3.002 Wh at 0.5A load
– 2.664 Wh at 1.0A load
– 1.949 Wh at 2.0A load

Download the specifications of the Sanyo HR-3U 2700 mAh NiMH batteries

1-2v-aa-1050-mah-gp-ekopower-nimh-battery

The 1.2V AA 1050 mAh GP EkoPower NiMH batteries we test here are the traditional NiMH type (not LSD ones) and are of quite low capacity for a rechargeable battery. The fact that these NiMH batteries are rated at only 1050 mAh makes it clear why that capacity is not written with large letters, but you need to take some time to actually find where it is written. These GP EkoPower batteries are rated at up to 1000 recharge cycles which is still a plus even though they will be offering significantly less capacity than a standard Alkaline battery per charge.


1-2v-aa-1050-mah-gp-ekopower-nimh-battery-capacity

We started the tests of the 1.2V AA 1050 mAh GP EkoPower NiMH batteries with a constant current discharge rate of 0.2A (200 miliampers) and they were able to provide us with just 991 mAh disappointing us a bit as they are supposed to provide 1050 mAh typical capacity. On the other hand the overall low capacity of these batteries may be the reason why the do not handle that well with 0.2A constant current load, it is possible that they will perform better in a low current drain situations. Also going up to 2A constant current load these batteries were clearly not capable of handling such high loads of about twice the battery capacity. So if you have these batteries you should stick to using them only in devices with low power requirements, what we can say is that we were not very satisfied with what we got from the 1.2V AA 1050 mAh GP EkoPower NiMH batteries.

The performance of the 1.2V AA 1050 mAh GP EkoPower NiMH Batteries in our tests:

– 991 mAh at 0.2A load
– 910 mAh at 0.5A load
– 747 mAh at 1.0A load
– 12 mAh at 2.0A load

– 1.205 Wh at 0.2A load
– 1.043 Wh at 0.5A load
– 0.798 Wh at 1.0A load
– 0.012 Wh at 2.0A load

8-4v-250-mah-imedion-nimh-battery

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.


8-4v-250-mah-imedion-nimh-battery-capacity

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.


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