4.8 Volt 18650 NiMH battery

Batteries and Chargers Rechargeable Batteries
1

http://www.rtdvapor.com/48V-NiMH-600mah-Battery-5vbatt.htm

Would there be any benefit to using this in a lighting application?

2

How many?

Probably non-LSD, heavier, less capacity... :)