As shown in the following figure, grab the plastic buckle and push it downwards to release the fastener.
I-8. Battery Holder
Batteries Installation: open the lock of the battery box, support the side of the battery box , and pull it out (as left picture);
Remove the battery out: put down the end of the battery box aligned to the card slot, and then press down the end handle,
and then lock (as right picture).
Charging the position: To connect the charger interface in this location.
I-9. Change of Pedals