Protect the cabin battery
Put a BatteryProtect in the lighting branch while leaving the solar charging path available to recover the battery.
Follow the circuit
01
Follow IN to OUT
Battery power enters IN and leaves OUT for the lights. Keeping the charger upstream avoids reverse charging current through the BatteryProtect.
02
Give GND its own lead
The thin GND wire is a reference connection. It goes directly to battery negative and carries no other equipment return.
03
Keep inverters separate
This branch is for DC loads. Victron requires inverter control through the inverter's remote input, not through a BatteryProtect in its main DC feed.
The source and this example
Victron's BatteryProtect simple-system diagram shows a fused battery feed, one-way load output, dedicated GND lead and factory remote loop.
The cabin lighting branch uses that arrangement. Solar remains upstream. Crimp models the power conductors; the cutoff threshold, delay and retained remote loop are not simulated.
- Victron BatteryProtect wiring examples ↗
Sections 3.1–3.3.1: orientation, GND lead and simple-system diagram.
Before you build
- Program the battery's shutdown and restart thresholds before connecting the load.
- Select the GND lead's 300 mA protection and verify the main fuse against the installed cable.
- Check the factory remote loop and actual device settings; the canvas does not test timed shutdown.
This is a planning example. Cable sizing uses Crimp’s ABYC-based method; the drawing does not certify an installation.
Cable sizes and connections · 12 conductors
Lengths are one way. Sizes and currents come from the same Crimp model as the drawing. Each drop value covers one drawn conductor; the full circuit includes its supply and return. AWG values are approximate counterparts to the metric areas.
| Connection | Length | Wire | Design current | Fuse | Drop |
|---|---|---|---|---|---|
| C1 · Victron 175W Mono + → Solar DP Isolator IN + | 3 m | 2.5 mm²AWG 13 | 9 A | — | 0.98% |
| C2 · Victron 175W Mono − → Solar DP Isolator IN − | 3 m | 2.5 mm²AWG 13 | 9 A | — | 0.98% |
| C3 · Solar DP Isolator OUT + → Victron MPPT 75/15 PV + | 30 cm | 1.5 mm²AWG 16 | 9 A | — | 0.16% |
| C4 · Solar DP Isolator OUT − → Victron MPPT 75/15 PV − | 30 cm | 1.5 mm²AWG 16 | 9 A | — | 0.16% |
| C5 · Victron MPPT 75/15 BATT + → Positive Bus Bar 1 + | 1 m | 2.5 mm²AWG 13 | 15 A | 20 A | 0.88% |
| C6 · Victron MPPT 75/15 BATT − → Negative Bus Bar 3 − | 1 m | 2.5 mm²AWG 13 | 15 A | — | 0.88% |
| C7 · Victron AGM Deep Cycle 12V/110Ah + → Positive Bus Bar + | 15 cm | 4 mm²AWG 11 | 15 A | — | 0.08% |
| C8 · Victron AGM Deep Cycle 12V/110Ah − → Negative Bus Bar − | 60 cm | 2.5 mm²AWG 13 | 15 A | — | 0.53% |
| C9 · Cabin lighting · 2 A − → Negative Bus Bar 2 − | 3 m | 1.5 mm²AWG 16 | 2 A | — | 0.58% |
| C10 · Positive Bus Bar 2 + → BatteryProtect 100 IN | 30 cm | 1.5 mm²AWG 16 | 2 A | 3 A | 0.06% |
| C11 · BatteryProtect 100 OUT → Cabin lighting · 2 A + | 3 m | 1.5 mm²AWG 16 | 2 A | — | 0.58% |
| C12 · BatteryProtect 100 GND → Victron AGM Deep Cycle 12V/110Ah − | 40 cm | 1.5 mm²AWG 16 | 0 A | 0.3 A | 0.00% |
A dash means no fuse is assigned to that conductor; upstream protection may apply. Recheck the exact device, holder and placement after edits.
Equipment · 8 components
- Victron 175W Mono
19.4 V · 9.03 A rated / planning output · 175 W · 23.7 V STC Voc
175W rigid mono panel, 12V nominal (Vmp 19.4V, Voc 23.7V) — works with PWM or MPPT controllers. 1485×668×30mm, 11kg, MC4 connectors.
- Solar DP Isolator
Illustrative two-pole PV disconnect. Select an actual DC-rated device for the array's cold open-circuit voltage and short-circuit current.
- Victron MPPT 75/15
15 A rated / planning output
75/15 battery circuit: 20 A fuse, within Victron's 20–25 A range. The controller's LOAD terminals are unused; the lighting branch is battery-fed.
- Victron AGM Deep Cycle 12V/110Ah
12 V · 110 Ah
40 A terminal fuse is this example's cable-protection choice. Verify the selected fuse, holder and interrupt capacity against the actual battery. Ah does not establish fault current.
- Positive Bus Bar
Positive bus bar — common feed with multiple output studs.
- Cabin lighting · 2 A
2 A load allowance · 24 W
Generic 2 A lighting allowance. Replace it with the actual lamps and hours used before relying on the energy budget.
- Negative Bus Bar
Negative bus bar — common return with multiple output studs.
- BatteryProtect 100
Factory remote loop retained. Crimp models the DC power path; the programmed cutoff voltage and 90-second delay are not simulated. GND is a dedicated 1.5 mm² lead with the manual's 300 mA fuse.
Crimp checks · 1 finding to review
These are the current engine findings for the saved example. They remain visible when you open it in Crimp.
- warning: Check fuse suitability: AGM 110Ah
More off-grid cabin examples
View all five →Solar lighting for a small cabin
Follow one solar panel through a controller and battery to a separately fused lighting circuit.
Monitor the cabin battery
Add a SmartShunt so both solar charging and cabin lighting pass through the battery monitor.
Two roof faces, two solar controllers
Give each solar array its own controller, then combine their battery outputs at the cabin's DC buses.
A separate inverter feed
Keep the inverter on its own heavy DC branch while solar charging and cabin lights share the same battery.
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