Tests and reviews of different batteries to help you find the Right One…

Friday
July 20, 2018

So far we have been testing and reporting the Amp-Hours (Ah) of the various batteries we have tested with the reason being that they are usually being rated in Ah regarding their capacity. But there is another unit that may actually give a better idea about the capacity of a battery and it is Watt-hours (Wh) when talking about batteries. This is precisely the reason why we have decided to also include not only the measured Ah in our battery tests, but also the Wh values – the good thing is that we actually should have all of these for the batteries we’ve tested so far and we are going to include the Wh results for all tests already done.

With each battery we usually have two important ratings, though both are usually revealed by the manufacturer only for rechargeable batteries – Voltage and Amp-Hours (usually written in mAh). Different batteries may have different voltages and capacities and normally you should do some math to know what you can expect from a battery if you know the power requirements of the device you need the battery for. Here is an example: an AA type of NiMH rechargeable battery that has a typical voltage of 1.2V and is rated at 2000 mAh (2 Ah) should be able to power a device requiring 2 Amps for 1 hour, or a device requiring 1 Amp for 2 hours and so on. However when measuring the actual battery performance lie in our tests you can clearly see that the starting voltage of a fully charger NiMh battery is higher than 1.2V and when the battery is considered discharged it is lets say 1V. So by switching from the Ah to Wh we can take into account the changing voltage of the battery while it is being discharged and get even better idea about its actual energy capacity, even though the Amp-Hours ratings usually do a good job for comparing batteries.

To get an estimate about the Watt-Hours rating of a battery you need to multiply the Amp-Hours by the Volt rating of the battery. So for the above example with 1.2V NiMH battery with 2 Ah capacity we are going to get 2.4 Wh, meaning that this battery can power a device with power consumption of 2.4 Watts for 1 hour, or for 2 hours if it uses 1.2 Watts and so on. But this is just an estimate, because as we’ve already said the voltage of the battery will vary while it is being discharged, so we need to do a thorough test measuring the full discharge cycle to get more accurate value. If you look at the discharge graph and the Amp-Hours in our battery tests with different loads you will see how the voltage is different at different load levels and this will also affect the Watt-Hour ratings as well.

Another thing that we are going to be adding soon are tables that will make it easier for you to compare the performance of all of the batteries that we have tested, of course the tabled results will be divided by battery type. This should allow you to quickly get an idea what could be the best choice for your particular needs for a battery…

The 1.2V AA 2100 mAh Fujicell NiMH batteries are the NiMH model from Fujicell with lower capacity as we’ve already tested their 2800 mAh NiMH that ended up more like 2500 mAh. So far the results we’ve seen from Fujicell batteries are very good in terms of available capacity for the price these batteries are being sold at. Not the highest possible capacity and usually a bit lower than the NiHM rating, though they are probably stating the typical and no minimal capacity is mentioned anywhere, but these batteries are available at a better price than most other similar products. Now we are going to test the 2100 mAh NiMH model from Fujicell to see what it can deliver, note that the 2100 mAh rating is probably the typical and the minimum capacity is probably 2000 mah, though it is not mentioned specifically.

Starting the tests of the 1.2V AA 2100 mAh Fujicell NiMH batteries with a low constant current discharge rate of 0.2A got us 2025 mAh as useable capacity and that is not bad, though a bit short from the stated (typical?) rating and acceptable if the battery is indeed a 2000 mAh minimum rating as we suspect. Going for higher load we are still getting pretty good performance in terms of useable capacity out of these batteries. It is interesting to see how the discharge curves for the voltage drop are kind of “grouped” – for the lower and higher current loads we are using for testing.

**The performance of the 1.2V AA 2100 mAh Fujicell NiMH batteries in our tests:**

– 2025 mAh at 0.2A load

– 1870 mAh at 0.5A load

– 1613 mAh at 1.0A load

– 1384 mAh at 2.0A load

– 2.456 Wh at 0.2A load

– 2.237 Wh at 0.5A load

– 1.725 Wh at 1.0A load

– 1.458 Wh at 2.0A load

The 1.5V AA Fujicell Alkaline batteries we test here are the standard and only Alkaline batteries that the company makes. We have already tested a few batteries from the brand and we’ve seen an average to above average performance, but this is normal considering that the batteries made by Fujicell are available at quite attractive price and price/performance wise they tend to be a good deal in general. The batteries we tested here were with an expiration date of 06-2019.

Time for the tests to start for the 1.5V AA Fujicell Alkaline batteries begining with a low constant current discharge rate of 0.1A and the result we got was 1988 mAh as capacity. A good result, but far from the best we’ve seen from other brands, and going for 0.2A we still get an average performance and good capacity. Increasing the constant current discharge load however to 0.5A and 1.0A shows that these batteries do not handle that well higher loads, so they are suitable mostly for low to moderate load applications. The results we’ve seen here confirm our expectations about good price/performance ratio and average to above average results in terms of capacity for Fujicell’s batteries.

**The performance of the 1.5V AA Fujicell Alkaline batteries in our tests:**

– 1988 mAh at 0.1A load

– 1640 mAh at 0.2A load

– 785 mAh at 0.5A load

– 225 mAh at 1.0A load

– 2.395 Wh at 0.1A load

– 1.949 Wh at 0.2A load

– 0.896 Wh at 0.5A load

– 0.246 Wh at 1.0A load