Err 26

Victron Energy Solar Charge Controller: “Err 26”

danger RV solar charge controller error codes

Safety Overheated terminals are a real fire hazard. Disconnect PV first (cover the panels or open the PV isolator) and then the battery before touching terminals. High-current DC arcs are dangerous and PV voltage can be lethal — if you smell burning or see melted plastic, stop and get a professional.

What it means

Terminal overheated. The power terminals (PV or battery screw terminals) got too hot, usually from a poor or loose connection causing electrical resistance.

Most likely causes

Loose terminal screw/bolt creating a high-resistance, heat-generating joint most likely
Undersized cable or wrong wire strand type for the current common
Corroded or dirty terminal contact less common

Safe checks you can do yourself

With everything safely de-energized, inspect PV and battery terminals for discoloration, melting or corrosion
Verify cable gauge is adequate for the controller's rated current
Re-tighten terminal screws/bolts to spec once the system is isolated

How to reset / clear Err 26

No manual reset needed: the error auto-resets after the terminals cool

When to call a technician

Terminals are damaged/melted, or the error returns after re-tightening with correct cable.

Applies to

SmartSolar MPPT (all) · BlueSolar MPPT (all)

FAQ

What does Victron Energy Solar Charge Controller code "Err 26" mean?

Terminal overheated. The power terminals (PV or battery screw terminals) got too hot, usually from a poor or loose connection causing electrical resistance.

How do I reset Victron Energy Solar Charge Controller Err 26?

No manual reset needed: the error auto-resets after the terminals cool

What is the most common cause of Err 26 on a Victron Energy Solar Charge Controller?

The most likely cause is loose terminal screw/bolt creating a high-resistance, heat-generating joint.

Related · Victron Energy solar charge controller

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On the SmartSolar MPPT RS / inverting models, Err 43 is an i…

Sources

MPPT Solar Charger Error Codes — Err 26 — Terminal overheated (Victron Energy)

Note: Official page confirms terminal-overheat meaning and wiring/torque cause.

● Last verified 2026-06-29 · compiled from manufacturer documentation. Codes can vary by model year — always cross-check your unit’s manual.