VoltCheck24 Engineering Calculator

Solar DC Cable Size Calculator for PV, Battery, and Inverter Runs

Estimate solar DC cable size and voltage drop for PV strings, battery connections, charge controllers, and low-voltage inverter wiring.

Open Interactive Calculator Open Solar Cable AWG and mm2 Table

How to use this calculator

Collect the values below from the equipment nameplate, data sheet, or field measurement.
Enter values using one consistent unit system and use worst-case operating conditions.
Review the result, margin, and engineering note before selecting hardware.
Cross-check the result with the related calculator and save the review for your project record.

Input checklist

PV, controller, battery, or load current
One-way outdoor cable distance
System voltage and target energy loss
Cable temperature, UV, and connector ratings

Example field question

Use this calculator when a design review or site issue requires a quick engineering check before a detailed manufacturer selection.

Common mistakes to avoid

Do not mix nominal values with measured worst-case values. Keep units consistent and include cable, temperature, duty, and derating assumptions where applicable.

Standards and validation

Review the result against local codes, IEC/NEC/NFPA/ISO practices when applicable, project specifications, and the latest manufacturer data sheet.

Recommended workflow

Start with the primary calculation, then use the related tool to check the next design dependency. Save or print the result only after the assumptions and worst-case conditions are confirmed.

Start with the primary inputs Check the related dependency

Formula and Inputs

Solar DC cable review combines operating current, one-way distance, conductor resistance, and allowable voltage-drop percentage.

Industrial Use Cases

Use this page for preliminary PV extension cables, battery-to-controller wiring, controller-to-load circuits, and off-grid DC distribution.

Engineering Note

PV systems require final code-compliant design. Confirm conductor temperature rating, outdoor/UV rating, connector rating, maximum current, fusing, and local solar installation rules.

FAQ

What voltage drop should I use for solar DC cables?

Many preliminary PV designs target low voltage drop to reduce energy loss, often around 2-3%, but the final target depends on system voltage, economics, and code requirements.

Can this replace solar code design?

No. It is a preliminary voltage-drop sizing aid; final PV conductor selection must follow local electrical and solar standards.

Preliminary engineering reference only. Confirm final selections against current standards, project specifications, and manufacturer data.