A loss of one volt may seem minor on a 230 V circuit, but it represents more than 8% of a 12 V supply. Low-voltage DC systems therefore often need much larger conductors than their current alone might suggest.
Always include the return path
Enter the one-way distance when using our calculator. The DC formula doubles that distance to include both positive and negative conductors.
High-current loads need special attention
Inverters, winches, pumps, heaters and battery chargers can draw substantial current. Keep cable routes short, use suitable flexible cable, protect the circuit correctly and follow equipment manufacturer instructions.
Connections add resistance
Terminals, fuses, isolators and joints contribute additional resistance that a simple conductor calculation does not include. Good crimping, clean contact surfaces and correct tightening are essential.
This article provides general information only. Electrical installation design and verification should be completed by a competent person using the current regulations and manufacturer data.