on board 12V battery charger from 24V

[Countryboy21]

ok i think i found a company that make a perfect charger for the truck. it takes the 24V from the batteries and gen and charges a 12V battery that all the other accessories can be run off of. i you buy the same size battery as you already have on the truck then if one of your starting batteries blows up or dies then you can swap out the battery for a fully charged one!
DC Input Battery Chargers for Lead Acid and SLA Batteries, for charging batteries from vehicles and other low voltage sources

 

[CobraCDR]

Have you tried this or are you just researching it and looking for comments? Sounds good in theory...