Not using the batteries and carrier. I can probably use my programmable DC power supply to get it done. It looks like the front of the carrier has both the POS and NEG contacts. So I'd feed 14.8 VDC, which is 3.7 Volts Per Cell - Nominal power from the supply to the appropriate contacts on the head and the supply will read Voltage and current. Volts X's Amps will give power used by the entire light. From that number, we can deduce what the "100 Watt" mfg figure is describing - Total power or power to the lamp. If the number is 120 - 130 Watts, then we can deduce that there's close to 100 Watts to the lamp. If the number is 100, then subtract btw 20 and 25% and that will be power to the lamp.