The REDARC BCDC Alpha range charges an auxiliary battery from vehicle and solar power. Alpha25 and Alpha50 are compact in-vehicle chargers, while Alpha50 R adds a separate battery-monitoring arrangement for more extensive system management. Compare each manufacturer's exact charger number and select any wiring kit by battery location and charge-current rating.
Identify your Alpha charger and the correct wiring-kit application
| REDARC number | Product / application | Output | Identify before ordering |
|---|---|---|---|
| BCDC12025B | BCDC Alpha25 | 25A | Vehicle and solar DC charging |
| BCDC12050B | BCDC Alpha50 | 50A | In-vehicle charger with larger charging capacity |
| BCDC12050R | BCDC Alpha50 R battery manager | 50A | Separate battery monitor with R-Bus wiring; no engine-bay installation |
| BCDCWK-102 | Alpha25 across-engine-bay kit | 25A charger | Start and auxiliary batteries on opposite sides of the engine bay |
| BCDCWK-103 | Alpha25 middle-of-vehicle kit | 25A charger | Auxiliary battery located in middle of vehicle |
| BCDCWK-105 | Alpha50 side-by-side engine-bay kit | 50A charger | Start and auxiliary batteries alongside one another |
| BCDCWK-108 | Alpha50 rear-of-vehicle kit | 50A charger | Auxiliary battery located at the rear of vehicle |
Alpha wiring drawing: components and terminal identification
| Factory element | Purpose | How it differs |
|---|---|---|
| START BATTERY positive terminal | Receives protected vehicle/start-battery supply | Red cable; ignition trigger used for certain smart alternators |
| SOLAR positive terminal | Connects unregulated panels within the 9–48V voltage range | Alpha25 maximum solar array 500W; Alpha50/50R 1000W |
| AUXILIARY BATTERY positive | Delivers regulated charging power to the house battery | The charger output must be fused and cable-sized for the installed unit |
| GROUND | Common system negative | Follows REDARC's original wiring and earthing diagram |
| Vehicle ignition trigger | Enables appropriate low-voltage/variable-alternator operation | Wiring depends on alternator type, not merely vehicle make |
| Battery temperature sensor | Monitors the auxiliary battery when supported | Mount to battery as described in the correct Alpha install guide |
| Alpha25 / Alpha50 controller button | Selects setup and charging preferences | May pair with REDARC app for detailed configuration |
| Alpha50 R battery monitor | Tracks current, voltage and state of charge | Has a separate monitored-battery assembly and battery-sense wiring |
| R-Bus adapter and cable | Connects Alpha50 R main unit and monitor | Not part of the basic Alpha25 / Alpha50 drawing |
| BCDCWK wiring kits | Cables, fuses, holders and connectors to suit the specified installation position | Auxiliary battery ground cable and solar-to-Anderson cable sold separately |
Original REDARC wiring and terminal diagrams
The factory illustrations identify the cables, fuses, terminals and charging connections for the specified model family. Open them at full size when installing or servicing equipment.
REDARC Alpha25/50 original solar, ignition and auxiliary battery layout
REDARC Alpha50 R original battery monitor and R-Bus wiring layout
Select the charger generation and wiring kit separately
The Alpha solar input supports 9–48V and the manufacturer lists a maximum array of 500W for the 25A model or 1000W for the 50A models. The 50R is not approved for engine-bay installation. The BCDCWK kits shown are identified by REDARC as Alpha25 or Alpha50 installation kits; do not assume they include the separate battery monitor or that an Alpha50 wiring kit automatically fits the Alpha50 R. Verify the charger, battery location, cable route, current limit and battery settings with an auto electrician.
Related RV battery-system references
See the matching chargers and accessories
Select a photo to open its NewRVParts listing. Similar-looking components may have different current limits, terminals or fitment.
BCDC12025B — REDARC Alpha25 12V DC-DC Charger25A; adjustable charge settings and Bluetooth
BCDC12050B — REDARC Alpha50 12V DC-DC Charger50A; suitable for engine-bay mounting
BCDC12050R — REDARC Alpha50 R Battery Manager50A; separate battery monitor; not for engine bay
BCDCWK-102 — REDARC Alpha25 Across-Engine-Bay Wiring KitFor Alpha25 batteries across the engine bay
BCDCWK-103 — REDARC Alpha25 Mid-Vehicle Wiring KitFor Alpha25 mid-vehicle auxiliary installation
BCDCWK-105 — REDARC Alpha50 Side-by-Side Wiring KitFor Alpha50 side-by-side battery setup
BCDCWK-108 — REDARC Alpha50 Rear-of-Vehicle Wiring KitFor Alpha50 rear-mounted auxiliary battery