Unboxing: 3 way battery disconnect switch 12-48 volts

Amazon Affiliate Link: https://amzn.to/4krvugj Price as reviewed: $26 Battery Disconnect Switch 12V-48V 300A Heavy Duty 4-Position Battery Switch Selector, Waterproof Ignition Protected Marine Battery Kill Switch for Car, Boat, RV, Truck, ATV This battery switch is designed to connect your boat motor to 1 or 2 12 volt batteries. You can select battery 1, battery 2, or combine both battery inputs together. This can allow you to have a primary and backup battery, or use both batteries are once for starting (or a trolling motor). You'll need to provide your own cables and ring terminals to fit over 10mm lugs, but the package does include 3 flexible rubber cable boots to protect the terminals. The switch includes a plastic box on the back with one cutout already open (and the other 3 sides can be broken out as you need to route wires) and 4 mounting screws. Alternatively, you can drill a hole in a panel and flush mount the switch with the terminals/wires behind the panel, but you'll have to provide your own mounting hardware for that. I tested the functionality of the switch and it connects/disconnects the various terminals as advertised, and has 0 ohm resistance between the connected terminals. The terminals are certainly large enough to handle 300 amps, but I couldn't examine the actual switch mechanism. It feels relatively tight and solid, but 300 amps is a lot of power. I'd feel comfortable putting 50-100 amps through it, but I'd want to test it at 300 amps and check for resistive heating before I trusted it at the full rated power level.