Best toggle switch to cut power while charging lithium battery?

[Remi]

I bought a monster marine lithium battery to run my AT2 and elite FS 9. I’d like to install a toggle switch of some sort to kill the power to both while charging the battery. Has anyone done anything like this or have suggestions on what I should buy to do this?

 

[Maxwell]

i have that for my ice fishing rig, but i don't use it in my boat. I use the yellow wires to power all my Lowrance Accessories. all three of my graphs are hooked to a buss bar for the yellow wire. I've seen others put a kill switch on it, but if you stop the sonar when not in use from your head unit, it turns the transducer off, but the box still runs...