Westward Booster Cable 4 AWG 20 Ft 400 A Parrot Jaw

4 AWG Booster Cable for Heavy-Duty Jump Starting

This 20 ft booster cable uses 4 AWG copper conductors rated for up to 400 A of current. It is built for heavy-duty use on larger vehicles where thinner cables would limit starting power. The spring-loaded parrot jaw clamps grip battery posts securely during the jump start process. It suits fleet operators, tow services and drivers who need reliable cold-weather starts.

Practical Limits of 4 AWG at 400 A

The 4 AWG gauge sets the practical ceiling for current delivery; drawing more than 400 A risks overheating the copper and softening the jacket. At the full 20 ft length, voltage drop under peak load becomes noticeable on severely discharged batteries. The crimped connections are factory sealed but cannot be field repaired if a strand breaks. California Proposition 65 warnings apply because the jacket materials contain listed chemicals.

Capacity and Headroom for Typical Starts

A 400 A rating provides comfortable headroom for most V8 petrol and light diesel engines in normal temperatures. The 20 ft reach allows battery-to-battery connections between parked trucks without moving either vehicle. In extreme cold or with completely flat batteries, the cable reaches its thermal limit faster than heavier 2 AWG or 1 AWG alternatives. It is not suited for continuous high-current loads such as winching or welding.