Aux (Under hood) battery in Interstate

[Lineolated]

Our 2014.5 AI has 2 vehicle batteries: the starter battery under the driver’s feet and an identical battery under the hood (MB manual refers to this as the “additional battery”). The additional battery is an option that a buyer may choose to order.

I can’t figure out what Airstream is using the 2nd battery for. If you know, please enlighten us!

Thanks in advance.

[JC2]

My understanding is that it's not hooked to anything. It's used for auxiliary current. I run a handicap lift from it but nothing else. Seems to work great.