Victron SmartSolar MPPT 100/20 wiring diagram

Connect the solar array to PV + / PV − and the battery to BATT + / BATT − through its protected charge circuit. The drawing shows these two circuits; the controller's separate LOAD terminals are not drawn.

For automatic battery-voltage detection, follow Victron's connection order:

• Battery first: check polarity, connect the battery, wait 10 seconds and verify the detected voltage in VictronConnect.
• Loads next, if used: check the LOAD limits below before connecting them.
• Solar last: connect PV after verifying the battery settings. Connect VE.Direct if needed.

Leave room for cooling and protect the terminals. Victron's mounting instructions specify a vertical installation, terminals down, on a nonflammable surface, with 100 mm above and below. A protective enclosure or optional WireBox must still allow ventilation; fitting the controller inside a small box does not establish adequate cooling.

Use flexible, fine-stranded copper with unsoldered ends. The same manual specifies 0.75 Nm for BATT, PV and LOAD terminals. Keep insulation outside the clamping area and check the finished connection; terminal capacity alone does not establish that a particular wire-and-ferrule combination fits.

Compact enclosures and ferrules raise practical questions. An October 2026 compact-system discussion includes concerns about cooling space and conflicting ferrule advice. These comments identify installation questions, not a measured overheating failure.

For this model, a 2019 Victron staff answer permits wire without ferrules and describes using ferrules. They are not mandatory. If you use them, follow Wiring Unlimited's termination guidance: choose a ferrule and crimp shape that fit the terminal, and use a dedicated crimping tool. Tightening the terminal onto an uncrimped ferrule is not a substitute.

Use a separately protected battery circuit for an inverter. Its continuous or startup current can exceed the LOAD output's capacity. Victron describes remote on/off control through LOAD for compatible equipment; the required interface depends on the inverter.

LOAD supports 20 A continuous at 12 V or 24 V, but only 1 A at 48 V. Its programmable low-voltage disconnect does not make it a suitable power connection for every load.

The SmartSolar 100/20 charges 12 V, 24 V or 48 V batteries at up to 20 A. Its specifications give nominal PV power of 290 W, 580 W and 1160 W respectively.

Check these separate array limits:

• 100 V maximum open-circuit voltage: include the increase in panel voltage during cold weather.
• 20 A maximum PV short-circuit current: check the complete series/parallel array.
• Startup voltage: PV must exceed battery voltage by 5 V before charging starts.

The power terminals accept at most 6 mm² / AWG 10. A calculated larger conductor will not fit directly. Keep the battery run short, then check cable size, voltage drop and protection for the actual route.

Use battery-side protection at the bank end, a suitably rated PV disconnect, and connectors and cable appropriate to each circuit. Bluetooth handles local setup and monitoring; use VE.Direct when connecting to a GX device.