Blow the fuse here, not in the van.
Wire your van's power system on screen before you drill a hole. Batteries, alternator, solar, chargers, switches and loads are solved together as one real circuit, so every wire shows the amps it carries and the volts it loses.
This is the same copper math the simulator runs on every wire: resistance per foot from the gauge, doubled for the return wire, times the current.
Lead-acid and LiFePO4 batteries with internal resistance and a BMS, an alternator whose output follows engine speed, solar panels with a real current–voltage curve, a bench supply.
Boost and buck converters with voltage and current limits, 5 V and 3.3 V regulators, AC inverters, and a portable power station with solar input.
Smart isolator (REDARC SBI12), battery combiners (Victron Cyrix-ct, Blue Sea ML-ACR), echo-charge, DPDT switches, terminal blocks, shunt and power meter.
Fridge, CPAP, lights, pumps, stereo amp, starter motor, ESP32 boards, AC devices, or your own: name it, set watts and hours a day.
| Do this | The bench shows |
|---|---|
| Run 60 A through 10 AWG | The wire heats over time until the insulation burns through |
| Set a boost converter above 73 V into a power station's solar input | The input is destroyed the moment it sees that voltage |
| Wire 30 V straight into a lead-acid battery | The battery overcharges and is cooked after 30 seconds above 15.6 V |
| Fuse a branch above its wire's rating | The wire fails before the fuse notices |
| Put 150 A through a 100 A contact | The contact welds shut and stays closed |
Push 250 W into the power station through the boost converter without blowing anything.
A converter set to 30 V is wired to a starter battery. Charge it properly instead.
Get 3 A or more flowing back into the starter battery.
Engine running and sun out: 250 W of boost into one station and 400 W of solar into the other, all wiring sized right.
The Build view lays each terminal block out pole by pole, with the wire on every screw, and prints a wire cut list: gauge, length and fuse for every run, plus the total copper to buy. Auto-size sets every wire and fuse to the recommended size for a 3% drop target.
Van Power Lab is the electrical side of a Van-Ish build. The island module's battery bay is where these circuits end up.