Blue Sea Systems9003E e-Series Battery Switch, On/Off, Red

I have used several of these in off-grid power applications. They work well and are easily installed. I used a 3 and 5/8 inch hole saw to make the holes with the reverse mount option.

First thing I did when I bought a boat is install a second battery because a dead battery on the water is both likely, and extremely problematic. Or worse.If you've shopped for marine battery switches you've seen the "other" brand. The big round, surface-mounted one. Then you see this one and think, "it's just so small" or "how does it mount to my boat?"I took the leap of faith and couldn't be more pleased with the results.My first consideration was accessibility. I didn't want the switch to be buried inside a compartment that would make access difficult while on the water. That way I could easily switch between batteries when we're fishing, using the downriggers and playing music, and back to when we're running the main engine. The smaller size and flush-mounting capability of the Blue Sea switch were definite advantages in that regard.My other consideration was the power handling capacity of the switch, especially because of its smaller size. A quick look at the published specs shows continuous, intermittent and cranking ratings of 350A, 600A, and 2,000A respectively. Way more than needed for my application. Another bonus is the "make before break" design that keeps all of my electronics alive as I switch between batteries. I never switch with the main engine running.I invested another 10 bucks in a hole saw and drilled a hole in the battery compartment facing the cockpit, then installed the switch flush to the carpeted front face. Bolted it in with new stainless hardware, terminated the batteries and not only is it functional, but it also looks great. No telling about long-term reliability at this point, but I'm glad I opted for the built-in look and accessibility of this switch.

The switch was a breeze to install, feels very solid, and I expect it to last a long time. I'm sure this is a little over-kill for my single marine battery, but I'm willing to pay an extra twenty bucks for peace of mind. This switch has a very high threshold for the load of amps that occur upon starting the engine, and it's size and weight imply that I won't be replacing it any time soon. The ability to flush-mount it worked great and keeps it looking professional.Regarding my specific setup: I have a standard marine battery running to a 120hp Yamaha outboard. For the last couple seasons I have had an issue with the battery dying if I didn't use the boat for several weeks. Physically disconnecting the battery terminals after using the boat solved the problem, but it wasn't the most user-friendly solution for the rest of the family. The issue suggests a larger trickle from the battery than there should be, but it's not worth my time or money to figure out what device is pulling current even when the key is off. So the solution was to get a simple switch that does the same thing as physically disconnecting from the terminals. It's worked great so far; no battery drain after leaving the boat for a month.Originally I intended to mount it below the dashboard, but I ended up taking more simple route and mounted it closer to the battery in one of the compartments under a back seat. I used a 3 5/8" hole saw to cut through the plastic wall of the seat, about halfway up from the floor. Then I pushed the switch into the hole, marked the four locations of the bolts, drilled four small holes, and mounted the switch with four nuts and bolts.NOTE, I needed the following extra materials to install the switch:1. 3 5/8" hole saw (not needed unless flush-mounting, and you could use a different tool too)2. Four bolts and nuts (at least 3.5" in length, I forget the diameter)3. Wire and crimp-connectors to extend the wire from the battery to where I mounted the switch, remember that you only need to extend the positive (+) cable to the switch)

This battery switch let you have two different sets of batteries to runoff from. It has three choices. Battery one or battery two or battery one and two. The qualities is excellent. I’ve been using this switch for 14 years in my RV fifth wheel with absolutely no problems. I would recommend this switch.

These work and look very good. They’re easy to set up and are very good value for the money. They are not durable the switch functions good for a while, but they eventually break I have been through multiple. Having a battery switch, preserves the battery life and is necessary.

Excelente producto de muy buena calidad

Works as it should.

My Attwood battery selector gave up due to getting wet too many times so I replaced it with this simple on /off since that's all I need. Time will tell if it lasts longer.