OK, what's providing power to the DC side of the SSR? You have a motorola charger actually providing the power itself, but what is switching that power on and off? (What are you using as a temp controller?)
Tough to recommend a contactor, without knowing what your controller setup is....this is an example of one:
Amazon.com: Packard C230B 2 Pole 30 Amp Contactor 120 Volt Coil Contactor: Home Improvement
but it uses a 120V coil...