Are environmentally-friendly rechargeable batteries just as efficient in capacity and performance?
A Consumer Council joint regional test, the first of its kind in the Asia Pacific Region in collaboration with the International Consumer Research and Testing, has found almost all rechargeable battery samples to fall short of the capacity of their own claims.
Included in the test were 14 models of AA size Nickel Metal Hydride (NiMH) rechargeable batteries labeled with capacity ranging from 2,250 to 2,600 mAh.
Under the nominal capacity test, all samples exhibited some degrees of variance between the actual and claimed capacity.
Two samples in particular were found to fare poorly: the capacity of one test model was 42% and the other 52% less than their claims.
The discrepancy means these rechargeable batteries could deliver only half or less than half of the capacity expected of them by their users - a rather misleading claim to the consumers.
The batteries were put to an endurance test (of 100 charging multi-cycles on high drain appliances). The test showed that as the charging cycles increases, the capacity of the NiMH batteries would decrease gradually.
The results of the average capacity of the first and last 25 cycles of the 100 cycles were then compared to assess the endurance of the batteries. The comparison revealed that 5 of the models were only less than half of their initial capacity in endurance.
Furthermore, it was found that the stored energy of a rechargeable battery tends to decrease during storage - losing as much as up to 20% to 68% in 40 days.
So, if the batteries have been left unused for a long period, it may be necessary to recharge them again before use.
Generally, the higher the capacity the longer the usable time of the batteries after being fully charged. Higher capacity batteries are suitable for high drain devices, but could be more expensive to buy.
On the other hand, lower capacity batteries with shorter usable time are generally cheaper and more enduring.
In the course of the test, it was observed that on some labels was marked a number resembling the value of a battery capacity. This number, however, turned out to be the series name, and not the capacity, of the product.
For example, in one case, the series name 2600 appeared prominently both on the front of the package and the product itself, whereas its capacity printed in very small font on the back of the blister card was only 2500 mAh.
This practice could be confusing to the unwary consumers who may mistake the product series name as the capacity value of the battery.
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