24V/36V/48V system on class A or C mothorhome for generator

[deeperblue]

Hi,

The reason I mentioned class A or C motorhome is because they generally share some common characteristics in their AC/DC system. I am comparing the options of 12 vs higher voltage system. In this post, I want to limit the discussion to the effect in generator.

Usually on class A or C, there are built in generators and by default house batteries are used to start the generator. That means the generator uses12V DC as its starting power, and usually the starting current can be pretty high for a brief period.

If the battery system is upgraded to higher voltage system, then the house batteries can no longer be used to start the generator. How should the starting power be provided to generator? I don't think any DC step down converter can handle that much current (or at lease not within a reasonable cost).

Thanks!

 

[rodrick]

For backup purposes a dedicated starter battery is the smart option incase you run your house battery to low

 

[justinm001]

Mine came with a dedicated start battery for the generator. Run a trickle charger to it just so it's topped off.

In basic rvs they have a house/start merge button so if your chassis battery dies you can start from house, same if your gen battery dies you can start the gen from chassis.

A couple hundred bucks for a dedicated battery is well worth it.

 

[jberger]

You need to see if your generator has an alternator for charging, some of the smaller gensets do not have a generator output and they use the chassis batteries for starting. If it's got an alternator, then adding a dedicated starting battery for the genset, then an battery relay back to the chassis batteries makes a lot of sense.
I've used them, bidirectionally, sometimes the engine batteries need a bump from the genset, sometimes the genset needs a bump from the engine, etc.

 

[deeperblue]

Thanks. Looks like keeping a dedicated generator starting battery is the way to go.