12v Winch Wiring

[RoyJ]

What I did to avoid large and expensive cables is a rear battery, preferably pure lead agm. It acts as a buffer or large capacitor, and only needs two 4 gauge copper / 2 gauge aluminum cables back to the main batt.

It's rare, at least in my use cases, to sustain 300+ amp draw, especially with snatch blocks. With the engine running, I get better voltage at the rear winch than solely relying on long cable runs. The rear battery also runs the fridge and other accessories. Careful not to use lithium batteries not designed for high amp draw.

 

[Peter_n_Margaret]

Good solution.
AGMs are available as "fast recombination" (often used for cranking) or "slow recombination" (often used for deep cycle of lower amps). Fast recombination would probably be the best choice for this application.

In regard to Li, the batteries typically are good for high discharge rates, but often not the BMS, but higher capacity BMSs are available. I use a 30Ah LiFePO4 for cranking the 4L diesel engine. It has a 10 second CCA rating of 800A. It weighs just 4.5kg.
Cheers,
Peter
OKA196 motorhome