Our Ctec D250SE battery to battery chargers with bult in solar mppt offers a simple high quality charging system for your vehicle to maintain and charge a leisure battery when you are driving plus a simple way to add a small solar panel for off grid power. You can also add the smartpass120s to the D250SE for a high power management system allowing loads from the alternator up to 120amps for powering high powered equipment when the engine running plus emrgency start function, starter battery maintenence and a controlled output for your 12v devices which will cut power at a low voltage protecting your leisure battery.