Techno Line BC 250 Manuel D'utilisation page 21

During the process of charging, the display of voltage and percentage
will alternate on the LCD. The item of percentage will show the
percentage of the battery charged while the item of voltage will show the
voltage of battery. Once the battery is full, the voltage will display
permanently with the "Full" sign. The trickle charging will start shortly
afterwards.
Charging current that is around 250mA is the only default value in the
charging process.
The estimated charging time of different battery size is tabulated in
Table 1.
Table 1. Charging Time with Two Types of Battery Size
Size of
battery Capacity
AA 2600mAh
AAA 1000mAh
Battery Charging current (mA)
around 250mA
19
Estimated
charging time
12 hrs
6 hrs