The Dometic SC-DB-MPPT-30-12 (83838) and SC-DB-MPPT-40-12 (83839) are dual-battery MPPT solar charge controllers used in RV electrical systems. This guide identifies their solar and battery terminals, differences in charging capacity and the PowerTrak display options available in our store.
Locate the six MPPT controller terminals
The factory manual identifies Solar + and −, Battery 1 + and −, and Battery 2 + and −, followed by an RV-C communications connector, configuration switches and status LEDs. Use the numbered legend to identify each feature before looking at its exact position on the installed model.
Terminal identification, viewed from the factory diagram
| Factory callout | Label | What to identify |
|---|---|---|
| 1 | Solar + | Solar-array positive input |
| 2 | Solar − | Solar-array negative input |
| 3 | Battery 1 + | Primary/house-bank positive output |
| 4 | Battery 1 − | Primary/house-bank negative connection |
| 5 | Battery 2 + | Secondary/chassis-bank positive output |
| 6 | Battery 2 − | Secondary/chassis-bank negative connection |
| 7 | RV-C port | Connector for supported PowerTrak/RV-C communication |
| 8 | DIP switches | Controller configuration switches |
| 9 | LED indicators | Green, yellow and red status lights |
Where solar power and battery data go
The controller gives the primary battery bank charging priority. The secondary BAT2 output maintains a chassis or starting battery at up to 2.5A. A single-bank installation uses BAT1. A compatible PowerTrak display connects on the RV-C network; the controller alone is not a Bluetooth touchscreen.
Solar charging and primary battery
Additional connections
SC-DB-MPPT-30-12 vs SC-DB-MPPT-40-12
In a 12V RV solar installation, the 83838 is the 30A unit with a 600W solar input rating; the 83839 is the 40A unit with a 900W solar input rating. Both have a 96V maximum PV open-circuit rating and a secondary maintenance-charging output. Always account for increased PV open-circuit voltage in cold conditions before finalizing an array.
| Controller | Output rating | Solar array rating at 12V | Battery outputs | PV open-circuit limit |
|---|---|---|---|---|
| SC-DB-MPPT-30-12 / 83838 | 30A | 600W | 2 (BAT2 to 2.5A) | 96 Voc |
| SC-DB-MPPT-40-12 / 83839 | 40A | 900W | 2 (BAT2 to 2.5A) | 96 Voc |
They support selectable battery charging profiles, including lead-acid and properly managed LiFePO4 systems. Wiring gauge, protection and any larger array configurations must be selected using the installation manual for the exact controller and electrical layout.
Matching MPPT controller and display products
The cards link to exact model listings on NewRVParts. The PowerTrak options are separate monitoring accessories, not items included automatically with a bare controller.
Original Dometic installation reference
The Dometic controller manual includes the physical terminal diagram, wiring precautions and system connection instructions. The original six-terminal drawing is in section 3.4, printed page 13. For the latest revision, use the manufacturer's support library; the linked older Dometic manual is useful for identifying the referenced terminal layout.
View Dometic's original wiring drawing (manual, PDF page 13) · View controller specifications (manufacturer PDF) · Find the latest manufacturer manual