What model of converter do you have now?
When my converter went bad I didn't replace the whole unit just the converter.
I also up graded from a 55 amp to a 75 amp I did have to retro fit it it but was very minor.
I had a wfco and replaced it with an intelli power brand. Much better unit in my opinion.
but I used my wfco housing and circuits. Took about an hour and a half to modify case and install.
Pm me if you want more info
Consider a "smart" converter with 3 stages.
A smart converter will analyze your battery(s) and give you a better charge. They will not boil the battery dry if a wet cell, and bulge those Gel batteries.
But, you'll need a good charger, opposed to one that's the five and dime model.
Mike
Fyi intelli power brand is "smart" charger.
the charge wizard allows you to program full charge, normal charge and storage feature.
And was same price point as wfco brand
Linear Mode
