Information on the OGT Solar Charge Port

Charge port capacity, polarity, and advice on controllers

The solar charge port on our trailers is an SAE type.   It is somewhat unconventional in that the visible, male prong on the port on the trailer is positive - this so that the positive lead coming from the charge controller is shielded:

Zamp solar port diagram


The port is rated for 20 amps of current.    It is wired directly to the 12v system, and is always live to the batteries, regardless of the position of the circuit breaker.     In line with the supply to the batteries is a 20 amp fuse.    20 amps is 240 watts at 12 volts.


There is no solar controller in the base trailers!   You must use a solar controller between your panels and this port.


MPPT controllers are suggested for overlanding as they can make the best use of compact solar panels.   PWM controllers can be used, they are said to be roughly 75% efficient vs 95% for MPPT.

Here are some manufacturer links for solar controllers:


Contact the manufacturer of your chosen charge controller for technical assistance if required; additional information on our batteries/electrical system is here:


If you have more questions, email


Happy charging!


The OGT Warranty dept.