User manual

37
It is interesting that the capacity in the NiZn rechargeable battery is not indicated in
milliampere, but in milliwatt hour.
The voltage of a freshly charged NiZn-cell is at approx. 1.8 V and the discharge
end voltage, depending on current load, at about 1.2 V. Since the cell type is still
rather new, there is little experience with the cycle number yet.
Rechargeable battery cycles means the number of times the rechargeable
battery cell can be completely charged and discharged before it is rendered
useless.
The required charging technology for the NiZn rechargeable batteries is generally
simple and similar to the charging technology of lead rechargeable batteries.
Processor-controlled chargers offer a higher safety standard and better charge
efciency with more options for charging and discharging technology.
The charging principle
Charging takes place with a current limitation that is about 0.5 to 1 times the
rechargeable battery capacity (0.7 A to 1.5 A in the AA type). The charging
end voltage, i.e. the voltage when the rechargeable battery is fully charged,
is approx. 1.9 V. At the same time, the charging current reduces to less than
0.05 C (in the AA cell 75 mA) at the end of charging.
The specic energy density is approx. 50 Wh/kg, which is about the same
as for the NiCd rechargeable batteries, but less than in the NiMh- and the Li
rechargeable battery.
C means the capacity of the rechargeable battery, usually in milliampere
hours (mAh).
A simple experimental USB charger with which the NiZn rechargeable battery cell
can be charged as shown in g. 036 as a plug board setup. The smaller AAA micro
rechargeable battery with 550 mAh is used as a rechargeable battery cell.