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.


The 9V Sony Ultra Super Carbon Zinc batteries we test here are rated with up to 3 years shelf life and are marked for use up to 11-2015. The Sony website does not have detailed specifications about these batteries, so we have to check them out by testing the actual capacity we can get out of these. Considering the fact that we are talking about a Carbon Zinc battery we don’t have very high expectations, even though Sony labels these batteries as Ultra Super.


To test the capacity that 9V Carbon Zinc batteries can provide we are using a constant current discharge test with 0.05A load (50 miliampers) due to the fact that the total capacity of these batteries is not that high and they are not intended for use in situations where high current loads can be expected. The 9V Sony Ultra Super Carbon Zinc battery we have tested here managed to provide 151 mAh capacity before hitting the 5.4V cutoff voltage and that is actually quite normal performance for a 9V Carbon Zinc battery as these usually provide less capacity than Alkaline batteries and are a bit cheaper compared to Alkaline.

The performance of the 9V Sony Ultra Super Carbon Zinc Batteries in our tests:

– 151 mAh at 0.05A load

– 0.998 Wh at 0.05A load


2S 6.6V 2000 mAh Robitronic LiFe batteries are intended for use as a receiver battery packs in remote control models such as nitro cars – to power the servos for throttle and steering as these cars use fuel not electricity for their engines. The good thing about LiFe batteries is the fact that they have much steadier discharge curve than traditional LiPo batteries, so they can provide a more constant voltage under load in almost their full capacity. Since however the manufacturer or the brand Robitronic that these batteris go under does not give a lot of details we’ll need to check how good these batteries actually are. The 2S 6.6V 2000 mAh Robitronic LiFe battery uses two cells to provide 6.6V and each cells consists of two smaller capacity cells that should be 1000 mAh each meaning that the battery is 2S and 2P (two cells in series and 2 in parallel).

Official Battery Specifications:

– Capacity: 2000mAh
– Voltage: 6.6V
– Dimensions: 56 x 32 x 32 mm


Starting the tests with a 0.5C discharge rate (1.0A) for the 2S 6.6V 2000 mAh Robitronic LiFe battery we’ve managed to get 1.77 Ah as a maximum capacity, a value that is a bit shorter than the official rating of the battery. So it seems that instead of 2000 mAh this LiFe battery is more like 1800 mAh and the good thing is that it can handle very well higher loads such as 10A constant discharge while still providing almost the full capacity it offers. Not that you will need constant loads of up to 10A for the servos in an RC model, but you can be sure the battery can handle even higher peaks without problems.

The performance of the 2S 6.6V 2000 mAh Robitronic LiFe Battery in our tests:

– 1.77 Ah at 1.0A load (0.5C)
– 1.76 Ah at 2.0A load (1.0C)
– 1.75 Ah at 5.0A load (2.5C)
– 1.73 Ah at 10A load (5.0C)

What you should have in mind though is that as with other small batteries that use thin cables passing higher current such as 10A or even higher as a constant load is not a good idea as they will get hot and may melt and short the battery, and that is something you don’t want for sure.