Can the Portable Power Pack be connected as the 3rd battery? Connected in-line from the the auxiliary battery that is fixed in the vehicle allowing it to charge while driving, but then also run off solar when left at camp?

The National Luna power pack can be connected to the vehicle’s auxiliary battery, keeping in mind that once the solenoid engages, it connects the batteries in parallel and the alternator is put under strain as 3 batteries need to get charged. In almost all cases, the battery in the NLPP is a different type than the batteries fitted in the vehicle. Charging different types of batteries inline is not ideal as each battery type reacts differently to charge. The battery will charge and care must be taken not to drain the battery too much as it will take much longer to top up. The grey 50A plug on the side of the electrical panel can be used as a solar input plug. Be sure to connect the regulator to the battery first, via the 50A plug, before connecting the panel on the regulator.