See what shore charging puts back
A Blue Smart charger and SmartShunt share one house battery. Both charging and lighting current pass through the monitor.
Follow the circuit
01
Keep returns on the correct side
Only battery negative connects to the shunt’s battery side. The charger and lights connect to its system side so their current is counted.
02
Understand the reading
With lights on, some charger output feeds them directly. The shunt reads what enters or leaves the battery, rather than the charger’s total output.
03
Connect the sense lead
The small fused B+ lead powers the monitor and measures voltage. It does not replace the heavy negative cables.
The source and this example
Rebuilt from Victron’s Blue Smart IP22 manual, section 5.3.3: a single-output charger with a SmartShunt.
Crimp selects a 20 A charger and 100 Ah battery, and adds a lighting circuit. This is the DC side only; mains wiring and protection are outside the drawing.
- Victron Blue Smart IP22 schematics ↗
Section 5.3.3, single-output model with SmartShunt; section 5.2 covers DC wiring.
Before you build
- Keep every future load and charger return on the system side of the shunt.
- Configure battery capacity and charging settings.
- Review the mains installation separately before use.
This is a planning example. Cable sizing uses Crimp’s ABYC-based method; the drawing does not certify an installation.
Cable sizes and connections · 7 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 · Renogy 100Ah LiFePO4 Mini Core + → Fused supply split | 20 cm | 1.5 mm²AWG 16 | 20 A | 25 A | 0.36% |
| C2 · Victron Blue Smart IP22 12/20 BATT + → Fused supply split | 1 m | 2.5 mm²AWG 13 | 20 A | 25 A | 1.09% |
| C3 · Victron Blue Smart IP22 12/20 BATT − → Victron SmartShunt 500A LOAD − | 90 cm | 2.5 mm²AWG 13 | 20 A | — | 0.98% |
| C4 · Victron SmartShunt 500A BATT − → Renogy 100Ah LiFePO4 Mini Core − | 30 cm | 1.5 mm²AWG 16 | 20 A | — | 0.55% |
| C5 · Renogy 100Ah LiFePO4 Mini Core + → Victron SmartShunt 500A B+ sense | 50 cm | 1.5 mm²AWG 16 | 0 A | 1 A | 0.00% |
| C6 · Fused supply split → Cabin lights + | 2.8 m | 1.5 mm²AWG 16 | 2 A | 3 A | 0.51% |
| C7 · Cabin lights − → Victron SmartShunt 500A LOAD − | 2.7 m | 1.5 mm²AWG 16 | 2 A | — | 0.49% |
A dash means no fuse is assigned to that conductor; upstream protection may apply. Recheck the exact device, holder and placement after edits.
Equipment · 5 components
- Victron Blue Smart IP22 12/20
20 A rated / planning output
DC-side example of the Blue Smart IP22 12/20 single-output model. Its mains inlet, AC protection and earthing are outside this drawing. Simulate assumes an available AC supply.
- Renogy 100Ah LiFePO4 Mini Core
12.8 V · 100 Ah
Crimp-selected battery and assumed cable lengths. Its internal BMS is part of the catalog model; prospective fault current and the exact fuse product remain unverified.
- Fused supply split
A wire splice — any number of cables can meet here. Born from a cable dropped into empty space; promotes to a real junction once a second cable lands on it.
- Victron SmartShunt 500A
Battery negative is the only power connection on BATT−. Charger and load returns use LOAD−. The thin B+ lead is a fused voltage/power lead, not a return.
- Cabin lights
2 A load allowance · 24 W
5m warm-white strip, ~24W total.
Crimp checks · 2 findings to review
These are the current engine findings for the saved example. They remain visible when you open it in Crimp.
- warning: Grounding path missing: BS IP22 20
- warning: Check fuse suitability: Mini Core 100Ah
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Crimp for AI agents · public beta
Ask your AI. Check the plan in Crimp.
Connect ChatGPT, Codex or Claude Code to look up components, calculate wire and DC-DC charger sizing, or build a small draft you can inspect and edit. Missing facts and assumptions stay visible.
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