Under Hood Jump Box: How Does This Work?

[Dead Parrot]

Don't see any cables that look heavy enough to be jumper cable rated. I do see two switches and a fuse holder. Given the various batteries, could be a voltage converter to keep everything charged.

Two 12v batteries in series will give the 24V a lot of heavy duty vehicles need to start. The 6V battery could be to jump the odd ball old vehicle that is still 6V. Both are something a general purpose wrecker would need.