Archive for the ‘NiCd/NiMH Batteries’ Category

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.

1-5v-aa-3200-mah-mex-cell-nimh-battery

The 1.2V AA 3200 mAh Mex Cell NiMH batteries are a clear example of a Chinese manufacturer labeling rechargeable NiMH batteries with higher capacity then they actually are. These batteries are supposed to be 3200 mAh, however they are being sold at a price of NiMHs with half that capacity, so this is supposed to raise some suspicion. So when you see batteries with very high capacity that are suspiciously cheap and from a brand that you’ve never head of, then you should be careful. Anyway, lets us see what is the actual capacity of these batteries and what current they can handle.


1-5v-aa-3200-mah-mex-cell-nimh-capacity

The maximum capacity we’ve got from the 1.2V AA 3200 mAh Mex Cell NiMH batteries at the minimum constant discharge rate of 0.2A we are using for testing NiMH batteries was 1486 mAh or more than twice less capacity than the batteries are supposed to provide. The only good thing here is that the batteries are handling pretty well with a current load of up to 1A, but going for 2 amps current draw and the voltage quickly drops below the 1V cutoff that we are using.

The performance of the 1.2V AA 3200 mAh Mex Cell NiMH Batteries in our tests:

– 1486 mAh at 0.2A load
– 1416 mAh at 0.5A load
– 1237 mAh at 1.0A load
– 145 mAh at 2.0A load

– 1.847 Wh at 0.2A load
– 1.700 Wh at 0.5A load
– 1.418 Wh at 1.0A load
– 0.148 Wh at 2.0A load

Definitely not worth buying these batteries as they are not delivering the promised capacity, not even half of it, they are actually something close to 1500 mAh and even though they are cheap, you will most likely get a better quality 1500-1600 mAh batteries for the same price. Be careful with unknown brands promising very high capacity battery at way too attractive price!

1-5v-aa-2400-mah-nimh-turnigy-lsd-battery

The 1.2V AA 2400 mAh NiMH Turnigy LSD batteries are NiMHs of the newer Low Self Discharge type that retain significantly more of their capacity over time as compared to the normal NiMH batteries that have faster self discharge. According to Hobby King selling these batteries they should not loose more than 30% of their charge in the course of a year when not being used. These Turnigy LSD batteries are rated with 2400 mAh typical capacity and not maximum capacity, though we are going to check if that claim holds true or not.

Official Specifications:

– Category: AA batteries
– Capacity: 2400mAH
– Voltage: 1.2V
– Chemistry: NiMH
– Weight: 29g
– Dimensions: 51x14mm

We started testing the 1.2V AA 2400 mAh NiMH Turnigy LSD batteries with initial discharge to see what capacity they still had when we got our order from the online store in order to check their LSD capabilities. The capacity provided was about 60-65% of their typical rated capacity, though we don’t know when they were produced, but according to the claim of about 30% discharge per year they should be made about a year ago. The minimum initial discharge capacity we got was 1505 mAh and the maximum one 1543 mAh from four different batteries that we tested with.


1-5v-aa-2400-mah-nimh-turnigy-lsd-capacity

The 1.2V AA 2400 mAh NiMH Turnigy LSD batteries have managed to provide very good results in our tests providing 2380 mAh with a discharge rate of 0.2A that we tested as a minimum discharge rate and that is pretty good. The batteries also handle very well under high current constant discharge loads of 2A that was the maximum we tested with providing 1240 mAh. We do our tests of NiMH batteries at a constant current discharge rates of 0.2A, 0.5A, 1A and 2A or with about twice higher as compared to what we test Alkaline batteries at due to the fact that NiMH batteries tend to provide higher capacity and are able to handle better higher current draw.

The performance of the 1.2V AA 2400 mAh NiMH Turnigy LSD Batteries in our tests:

– 2380 mAh at 0.2A load
– 2149 mAh at 0.5A load
– 2139 mAh at 1A load
– 1240 mAh at 2A load

– 2.920 Wh at 0.2A load
– 2.553 Wh at 0.5A load
– 2.402 Wh at 1A load
– 1.270 Wh at 2A load

In overall the 1.2V AA 2400 mAh NiMH Turnigy LSD batteries are performing very well and are available at a very good price online, though the shipping cost makes it worthwhile only if ordering more batteries as these are only being sold online and shipped from Asia.


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