The aim of this Bachelor’s thesis was to investigate type AA batteries. The aim was to investigate how finger batteries should be used and to identify some of the ways that easily damage the batteries in household use. The batteries were used as effectively as possible.

Different disposable and rechargeable batteries were discharged by using cameras. Rechargeable batteries were used in many ways and loaded with three chargers. The NiMH batteries were charged with a rapid charger, in the normal way and in the way a NiCd battery is recharged. One finger battery was fully discharged by using separate resistors. The battery voltages were measured with a digital multimeter. The measurements were carried out while the finger batteries were discharged and loaded but also at other times. The aim was to find out the differences between the various batteries with regard to selfdischarging and temperature changes.

Good results were obtained with the disposable lithium battery and NiMH batteries. No significant difference was observed between the rechargeable NiMH batteries of different brands. Charging with a rapid charger didn’t seem to damage the rechargeable batteries on the basis of a few charge cycles. It was possible to charge the NiMH batteries in the wrong way and also to perform a full discharge a few times with no negative effects. Moreover, frost did not seem to affect the results. More research is, however, needed in order to get more reliable results.