Re: Looking at 1993 GV
Reply #20 –
A successful residential fridge installation usually requires modification to the coach electric system. While you can (sometimes) get along on the original components, some upgrades will make life easier, on you and on the fridge. To work well, the fridge will require clean, continuous power. This usually involves installing a more modern inverter, and (in some cases) additional battery capacity.
Most owners choose to upgrade their inverter to "full sine wave" when installing a residential fridge. You can do this by either replacing the old original "modified sine wave" inverter, OR by installing a new separate dedicated sine wave inverter that only powers the fridge. Then you can shut off the "big" inverter at night or when not needed. The small inverter will use less power in stand-by, so less drain on batteries.
You mentioned the coach in question has 2 house batteries. You will need to check on what type they are, and how big. We have a residential fridge, and 2 AGM8D house batteries (245 A.H @ 20Hr in each battery). I would consider this the minimum size house battery bank to support a residential fridge. When dry camping, if we go to bed with 80% remaining battery capacity (not unusual), then we are down to 55% by the time we wake up next morning. You don't want to pull your batteries down below 50%, so at this point we need to think about adding charge back into the batteries. That can be done by running a generator, plugging in to shore power, or using solar panels. One way or the other, operating a residential fridge on battery power will require using a charging source every day, rain or shine, hot or cold weather. Something to consider...
Having "auto start" for your generator is handy when you are away from the coach for extended periods. When you are at the coach, it is better for YOU to monitor your battery condition, and proactively decide when and how long to run generator. Which brings up another point: running your coach on battery power requires some means of accurately monitoring battery performance. Search this Forum for numerous posts on this subject - search for "Trimetric" to get started.
Good luck with your quest for the perfect coach for you!