I hadnโt seen those before. But makes sense and simple enough. Although for your purpose I believe it would require modification as it is made to simply disconnect one lead from the battery. Youโre not trying to disconnect the start battery, youโre trying to combine them when the charger (converter) is providing juice.
Looks like another low buck security solution for, say, an old car.
On a separate note, the quality has to be horrible for $25 and I wouldnโt trust it to work as designed very long. And in the proper use, youโd be running starting current through it which may be marginal with only a 250a rating if you were starting the engine in the cold weather.
I bought a similar ching Chong made headlight relay kit for our old truck. It works but itโs worth about what I paid for it. And it doesnโt work great.
There are several other ways to accomplish what you want to do but in a more preferable manner IMO.
From a simple Perko type cutoff switch to an ACR type switch for automatic combining or cutoff.
Also Iโd make sure youโre not creating some sort of ground loop or other issues as your rig should already have a charging circuit from the start system to the house batteries.
2016 Ram 2500, MotorOps.ca EFIlive tuned, 5โ turbo back, 6" lift on 37s
2017 Heartland Torque T29 - Sold.
Couple of Arctic Fox TCs - Sold
