No need to remove the battery when using an external power supply.
12V Driver for Cars, Vans, and Trucks
Power Supply: 9 to 12V DC (Not Included)
The Reindeer and Santa Claus Soldering Kit has 126 multi-color LEDs. No need to remove the battery even when using an external power supply. It is powered by 12V and can be used in cars, vans, trucks. It has an on/off switch and is powered by a 9V alkaline battery (sold separately).