When an inverter is connected to a battery, low voltage systems can actually have a very high current through the cables, as seen with large AC load devices like microwaves and washing machines, which can cause a draw over over 100 A from an inverter on a 12 VDC battery. Even larger motors can draw 300 or 500 A upon startup.
If cables from battery bank to inverter are too small in these situations, the current becomes limited and can fail to supply the necessary energy. Also, the correct size cables will impose less resistance, which in turn maximizes efficiency.
Copper lugs made with tin plated copper tubing and ⅜” holes, crimped or soldered to stranded cable, is the most recommended type of cabling. Additionally, heat shrink tubing, which will melt and seal wires under heat to protect against corrosion and moisture, can be used to insulate lugs and compression terminals. This tubing is sold in 6” lengths.
Use battery cables made with flexible, stranded, UL-listed copper wire with 3/8” diameter lugs between battery bank and fuse, power center, or inverter. These cables can also be fitted with 5/16” lugs. The standard marking white heat shrink tubing on black wire for negative, and red heat shrink tubing for positive.