The internal battery of the RACE RESULT System lasts for approximately 6-8 hours (passive ground antenna), or 24 hours (active loop). The external battery port can be used to connect a larger battery or a car (via the cigarette lighter) for longer uptimes without another power supply.

When determining the necessary size of a battery, calculate with a power consumption of 2 A using the passive antenna and 500mA using the active loop.

The system is sold with a special cable with XLR connector for the decoder on one end and a car connector on the other end. The pins are used as follows:

1: GND
2: +12V Input (10A Fuse)
3: NC
SHIELD = GND
 

Note that the external battery does not charge the internal battery, but instead power will be taken from both batteries, internal and external, at the same time.

You can use the Battery Booster to discharge the external battery first.