Sterling Power
Sterling BB1230 wiring diagram
12V-to-12V BB1230 rated at 30A input; output varies with charging voltage and losses. Blue-stripe manual specifies 40A fuses and 10 mm² cable as a guideline. Confirm stripe generation; this model has no solar input.
- Compatible systems
- 12 V
- Rated output
- 22 A
Wiring diagram
How the BB1230 30A is wired.
Open this example in Crimp to use your own parts and cable lengths. Review the assumptions and installation notes as you adapt the circuit.
Cable sizing for this example
Use the diagram as a starting point for your installation. Replace the example equipment and cable lengths with your own, and check the connections against your exact model's instructions.
3 m one way
12 V system
- Wire
- 10 mm² · 8 AWG
- Example fuse
- 30 A
- Design current
- 22 A
- Voltage drop
- 2.0%
Sized against ABYC E-11. The design current is the unit's rated output. The length is one way; voltage drop includes an equal-length return.
Run-length and manufacturer assumptions
The editable example uses 3.048 m (10 ft) runs unless a shorter run is stated. Metric overviews round these to 3 m. Adapt the parts and lengths to your installation before choosing cable and protection.
Supporting parts
- 6.1 m total of 10 mm² (8 AWG) marine cable
- Terminations for 10 mm² cable, matched to the equipment's screw terminals, leads or studs
- 30 A fuse and holder on the positive run
- Heat-shrink, strain relief and terminal boots sized to the cable
Check stud sizes, fuse type, run length and how warm the space gets against the gear you actually have before you order.
Installation notes
Before you install.
Open a question for model-specific guidance and sources.
Reviewed against manufacturer family documentation (rev. March 2021 V4 — blue/yellow stripe instructions), checked 2026-10-01. Exact variant details still require confirmation. Manufacturer documentation →
Which BB1230 is covered?
BB1230 identifies a 12 V-to-12 V battery-to-battery charger rated by its 30 A input current. Output current depends on input voltage, charging voltage, losses, and thermal conditions; the catalog's approximately 22 A output is an estimate, not a fixed manufacturer output rating.
Sterling publishes distinct stripe generations. This walkthrough uses the blue-stripe, March 2021 V4 manual; an older green-stripe V71+ manual has different startup behavior. Match the front label before applying settings. The removed catalog photograph showed a BBS combined solar charger, not a plain BB1230. A BB1230 has no solar input.
How are the terminals connected?
IN + is Engine Batt input and OUT + is Aux Batt output. IN − / OUT − both represent the physical common negative. The non-solar installation diagram calls for dedicated negative cable connections rather than relying on the chassis as the return path.
The symbol omits ignition pin 4, the BMS inputs, optional temperature-sensor pair, remote voltage sense, and remote-panel connector. These small connections carry control or sensing signals, not charge current. BMS1 stops charging on a 0 V signal; BMS2 stops it on a 2–17 V positive signal. Match the BMS output logic before wiring either input.
What protection and cable sizes are given?
The model-specific cable/fuse table gives 10 mm² / AWG 8 cable and 40 A fuses on both sides as a guideline for typical runs. Protect the cables at their battery sources. Longer routes require a voltage-drop and conductor check rather than blindly copying the guideline. The reviewed table does not give a numerical terminal torque.
What must be configured?
The blue-stripe default starts above 13.5 V and stops below 13.3 V; green V71+ uses different thresholds and a timed shutdown. For a variable-voltage alternator, follow the matching manual's ignition-feed mode and verify engine-off behavior.
The default sealed-lead-acid profile is 14.4 V absorption / 13.6 V float. Blue-stripe Lithium I and II provide 14.2 or 14.4 V charge, both with 13.8 V float. Confirm these against the battery manufacturer. Selecting a lithium profile disables reverse-polarity protection, making a polarity check before energizing especially important.
Which operating limits remain?
The blue-stripe unit is IP21 and needs a protected, ventilated installation. With the optional temperature sensor fitted, the lithium profile has a 0°C charging trip; without that sensor, do not assume this protection exists. The battery still requires a BMS. Confirm the hardware generation and stop/start behavior before treating the walkthrough's settings as applicable.
Fit check
Connect it to the rest of your system.
Describe your setup to draft a system with BB1230 connected. Review the selected parts and cable lengths, then edit the diagram in Crimp.
The model only picks parts and draws the connections. Every wire size and fuse rating still comes from Crimp's own sizing, never from the model.
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Technical reference
Specifications and terminal map.
Check the model, ratings and connection points against your own unit before choosing installation hardware.
Catalog specification
12V-to-12V BB1230 rated at 30A input; output varies with charging voltage and losses. Blue-stripe manual specifies 40A fuses and 10 mm² cable as a guideline. Confirm stripe generation; this model has no solar input.
- Compatible systems
- 12 V
- Rated output
- 22 A
- Planning charge current
- 21 A
Terminal map
Catalog connection points, current direction and planning limits. Check the manufacturer's pinout and connector ratings before installation.
IN +
positive · input
IN −
negative · input
OUT +
positive · output
OUT −
negative · output
Sources and sizing method
Equipment specifications. Model details, ratings and terminal roles come from the catalog. Check your unit’s label and current manufacturer documentation for its exact revision.
Example sizing. Sized against ABYC E-11. Boats built to UK or EU rules answer to ISO 13297 — check these figures against it before you build. Results use the example current and run length shown above. Set your actual equipment, lengths and installation conditions in Crimp before choosing hardware.
Read how the sizing worksNext step
Plan your installation with BB1230 30A.
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