Depends on the type of battery, and how its wired. Things have changed a lot since the old simple 12 volt battery, and converter days.
Roadtrek's ETrek packages are a lot more complicated than the old systems. They are using proprietary tech. and altering their system could cause some problems. I think that is the problem mrlandlord was running into. I think he also added 500 more pounds in batteries behind the rear axel. The added weight could affect the axels, and since he was also adding a rear carrier. could also affect the handling. If his axel broke because he exceeded the axel weight would the chassis warranty cover it? I doubt it.
I think the Etreks are wired for 24 volts.
I don't know how the CS, RS, and other models are wired, what type, size batteries they are using, but I would want to check with Rt before I changed, or added anything. Just to be on the safe side.
