Starting Battery cut off switch

[Fahntastic Life]

Being that I am slowly building out my Bus, I wanted a way to disconnect my starting batteries from the bus for when i am not working on it a week at a time.

my bus has three batteries to start. Not thinking, I went to the parts store and bought a standard battery disconnect and hooked it up.

Everything was fine till I moved back the metal toggle switch and tried starting the bus and the disconnection switch melted.

My question is: are you adding a disconnect switch for your main starting batteries. if not, what are you doing so they don't die when you're not using the bus weeks at a time.

if you are using a disconnect switch, what commercial size switch are you using.

Thanks,

[s2mikon]

I used a Cole Hersee 2000 amp disconnect switch. It was made in USA. NOT junk!

[rossvtaylor]

Did you get the kind that's a knife switch, which mounts on the battery terminal? Like this? If so, these are only rated for about 100-150 amperes. Your starter can easily double or triple that.



The only kind I'll use or install are made by Cole Hersee. They're $70-100 but rated for enough current that you won't have to worry about it.

[rossvtaylor]

Originally Posted by s2mikon

I used a Cole Hersee 2000 amp disconnect switch. It was made in USA. NOT junk!

I was typing that suggestion at the same time...the best and only disconnect switches for main battery use.

[s2mikon]

And don't use it to shut off the engine while running.

[jimmy649]

I wired in a battery charging solar panel and now they are so juicy all the time I think that starter winds off at triple speed!!

[David from Ontario]

My bus had a parasitic load that kept draining the starter batteries. For a while I kept a socket wrench handy and manually disconnected the batteries each time I parked the bus. That got old fast. From the Thomas dealer I bought a Cole Hersee kill switch and thick-as-your-thumb 0/4 cable. Also a hydraulic crimper. (It's a fire hazard if the cables are too thin and the ring connectors aren't crimped tightly.)
I didn't want the hassle of opening the battery compartment to access the kill switch, so I installed it next to the driver's seat. You need to interrupt only the ground (black) cable, but I also ran the positive (red) cable into the switch box I built. Why? I'll be installing a DC-to-DC converter so the alternator can charge the house batteries while I drive. I now have those connections inside the passenger compartment.

With apologies for the 34 minute run time, I made a video about the kill switch installation:
https://youtu.be/ojxiIze_ORU

[Booyah45828]

+3 on the cole hersee switches. I've installed them on semis as they're the only thing that will handle the current with any sort of reliability.

Also, like s2mikon said, make sure everything is powered off and there is no load present when turning them off or on. Not doing so will shorten the switch's life because of arcing.

[flattracker]

Crown had an option to install a battery switch in their buses. They used a Cole-Hersey switch that allowed for disconnecting either or both batteries. My "old Crown" has that option.


I also have a split configuration of my solar array on the "new Crown" to charge the starter batteries separately from the solar array or all five panels charge the house batteries. I installed a switch and a second charge controller to accomplish this.


My configuration always keeps the charge controller connected to the batteries but dis-connects two panels from the second controller and re-connects them with the house battery charge controller. This works well.

[Fahntastic Life]

Would like to say thanks to all for your suggestion. in the process of ordering that heavier kill switch. now its how to wire it. i do like the video of the kill switch inside the bus.

Thanks, all

[LargeMargeInBaja]

A battery disconnect is usually standard on HDT (Heavy Duty Trucks) such as semi-tractors and dump-trucks (tippers).
.
Eugene, Oregon.
We are frequent visitors to our local-owned family-operated HDT wrecking-yard (aka 'dismantlers'):
Anderson Brothers heavy-truck wrecking
2640 State Hwy 99 N at Beltloop
Eugene, OR 97402
(541) 688-8686
.
Walking through that magnificent outdoor museum, we see just about every truck has a disconnect on or near the battery box.
I bet they all end-up in the crusher.
I bet if you asked, you could get an armful for a couple-three fedbux.