Or just install LED overhead garage lights like I did. They cost almost nothing to run and flood the space with light. I have my overhead lights turn on based on motion or any of the doors to the garage being opened. In order for the lights to turn off automatically, all of the doors must be closed and no motion for 5 minutes.
To solve the battery problem, I am using a traditional low voltage motion detector (Bosch ISC-BPR2-WP12) designed for a home alarm system, tied into an Arduino MEGA with a W5500 Ethernet Shield. Also attached to the Arduino are all of the door/window sensors for the house (using old alarm panel wiring and magnetic reed switches) as well as a DHT22 Temperature and Humidity sensor. I also have a pair of relays attached to operate the pair of garage doors. The Arduino runs my ST_Anything Arduino Library, which also supports simple LUX sensors. Best part, no batteries to ever change.