The ePropulsion Spirit 2 Battery Solar Charge Controller allows you to charge the ePropulsion Spirit Battery Ultra with solar panels from 100W to 400W. One end plugs into the Spirit Battery Ultra, the other ends in standard MC4 connectors that hook up to your solar panel.
The charge controller can handle a maximum input charging current of 13A, and an open voltage of up to 45V. An MC4 to 12v outlet adapter is also included, which allows you to also charge your battery with a 12v outlet.