Summary

More batteries is better... from a usability perspective.  But when you start to deal with the physical issues posed by the batteries, less would be more.  Here is a discussion of the selection of the batteries. 

Here is a discussion of the physical mounting of the batteries.

Top view, installed batteries.  Click to enlarge...

Battery jumpers.  Click to enlarge...

Below is a diagram of the charging system, highlighting the Xantrex components that integrate the vehicle's power system with the grooming systems.

The XAR, alternator regulator, not shown in the diagram above, manages the output of the vehicle's alternator to become a multi-stage charging source used to help charge the grooming service batteries.  The Pathmaker device is an intelligent switch which connects the vehicle's power to the service batteries under the appropriate conditions.