Smartgen BAC06A generator battery charger.
It is designed for charging lead-acid starting batteries.
It uses a two-stage charging method (constant current and then constant voltage) to avoid overcharging.
It has a wide input AC voltage range of 95-280VAC.
It can automatically identify and switch between 12VDC or 24VDC output.
The maximum charge current is 6A for 12V and 3A for 24V.