Add panels without rewiring the roof. If your RV came with a Go Power! PWM controller (GP-PWM-30, GP-PWM-30-SB, GP-PWM-25) or a Zamp PWM controller and you want more solar, the limit you are hitting is the controller, not the roof. A 30A PWM controller passes panel current straight through, so a fourth panel pushes it past its rating. An MPPT controller lets you wire panels in series at higher voltage, keep the existing roof wiring, and harvest more from the panels you already own.
What changes when you go MPPT
- More from the same panels. MPPT tracks the array's maximum power point and converts excess voltage into charge current. Owners typically see 10–30% more harvest than PWM, most of it in cold weather, low light and early morning.
- Series wiring. Wire panels in series up to 100V open-circuit and the existing roof cable carries more power with less loss. No new cable runs.
- Headroom. The GP-RVC-30-MPPT handles 600W of solar at 12V and 1,200W at 24V. That is a fourth, fifth and sixth 160W panel on a 12V coach.
- Two batteries, one controller. On a motorhome, BAT1 charges the house bank first at full current and BAT2 tops up the chassis battery with the surplus. No trickle charger, no second device.
- Same brand, same bay. Mounts where the PWM controller was, uses the same PV and battery wiring, carries the Go Power! 5-year warranty.
Size the controller
| Your array (12V coach) | Controller |
|---|---|
| One 100–150W panel | 10A MPPT + Remote Kit |
| 190W–600W (two to six 100W panels, or up to three 190/200W panels) | 30A Dual Bank MPPT + Remote Kit |
| Over 600W at 12V | Two GP-RVC-30-MPPT controllers, stacked — or wire the coach for 24V and run up to 1,200W on one |
Keep each array's open-circuit voltage (Voc) under 100V after allowing for cold-weather rise — multiply the panels' rated Voc by about 1.25 for a safe check.
What about the screen?
Your PWM controller had an LCD on the unit. The GP-RVC-30-MPPT is built to live in the battery bay and report to a display inside the coach instead. The kit includes the GP-RVC-R remote: a surface-mount wall display with a 25 ft cable that shows battery voltage, charge current and totals, and adds Bluetooth so you can read everything in the Go Power! Connect app. If your coach already has an RV-C or PowerTrak display, you can buy the controller on its own.
Install notes
- Disconnect the PV array before the battery when removing the old controller, and reconnect the battery before the array when installing the new one.
- Set the battery profile (GEL, AGM, Flooded, LiFePO4 or Custom) through the remote or the app before connecting panels.
- Re-use the existing PV and battery cable if it is sized for the new current; 8 AWG is typical for a 30A run.
- Fuse the battery side per the installation manual.
- Zamp owners: the Zamp roof-port connectors stay; only the controller changes.
Choose your part
- 30A Dual Bank MPPT + Bluetooth Remote Kit — the drop-in upgrade for most PWM systems.
- GP-RVC-30-MPPT controller only — if you already have an RV-C display.
- 10A MPPT + Bluetooth Remote Kit — single-panel systems.
Frequently asked
Will MPPT work with my existing Go Power! panels?
Yes. Any Go Power! or Zamp panel works. MPPT lets you wire them in series, which is what makes the existing roof cable carry more power.
Do I have to rewire the roof?
Usually not. Series-wire the panels at the roof junction and keep the existing run to the controller. Check that the combined open-circuit voltage stays under 100V.
Can one controller charge my chassis battery too?
Yes. The GP-RVC-30-MPPT has two battery outputs: house bank first, chassis battery topped up with surplus.
Is it UL listed?
No. It is sold for aftermarket and DIY installation in the United States and is not intended for OEM production use. It cannot ship to Canada.
Certification and sale restrictions
These controllers are not UL listed. They are sold for aftermarket and do-it-yourself installation in the United States only and are not intended for OEM production use. Not available for shipment to Canada. Confirm compatibility with your coach and local requirements before purchasing.