Translation from Tamiyaタミヤ :
Tamiya LF-6.6V DC battery charger
Item No: 55103
Tamiya is the LF-6.6V battery charger for high performance. Supply direct current (DC power) to supply or 12V automotive battery can be charged to secure the simple one-button operation. In addition, LF-6.6V is connected to the connectors for the battery charger that came with the balance, the individual can keep the proper balance between charging the battery cell voltage. He also connected with the protection circuit, the main battery power and to protect the course. ※ AC100V to use the power supply is required sold separately.
Source : Tamiya