V1 Battery Disconnect/Isolation Switch

[jirwin]

I'm trying to think of the best way to install a battery isolation/disconnect switch on the car. What have you guys done? Please post pictures if you have any.

 

[Gtstorey]

Are you doing it to meet some racing organization rule? If so I think a lot have their own requirements on placement.

 

[jirwin]

Are you doing it to meet some racing organization rule? If so I think a lot have their own requirements on placement.

That was part of the reason I suppose. Also would be nice for winter storage since I have another dead battery because I procrastinated putting it on the trickle charger. I doubt SCCA autocross has any rules on that, but I honestly haven't looked into it. The most I'll probably do is autocross and messing around at the drag strip. Not sure what that entails. I imagine the more strict ones need something immediately accessible where you just pull something and the battery is disconnected?

 

[Gtstorey]

I think the more stringent ones want it at particular place on the car (one of the rear corners) but I'm not sure what the requirements are for killing all power (complete battery disconnect including starter) vs just normal operating power. If you just want to kill power to keep the battery from draining then installing a disconnect at the fuse box for that power should be fairly easy with the normal Goblin wiring.

I just installed a plug for the trickle charger near the fuse box to make it easy to hook up.

 

[jirwin]

I just installed a plug for the trickle charger near the fuse box to make it easy to hook up.

I had a cable too, but I think I forgot to put it back on when I put on new terminals last year.

I think the more stringent ones want it at particular place on the car (one of the rear corners) but I'm not sure what the requirements are for killing all power (complete battery disconnect including starter) vs just normal operating power. If you just want to kill power to keep the battery from draining then installing a disconnect at the fuse box for that power should be fairly easy with the normal Goblin wiring.

Yeah, I've seen stuff like this for drag cars where this just sticks out the back. Kinda hard to do when the battery is in the front though. I was thinking about trying to find one of the ones where they are a relay, and not a switch. That way I can put the switch wherever I want. Something like this.

 

[Gtstorey]

I'm not sure if even those will carry starter load. Their amp loads don't exactly match up. You also need to think about whether you want to totally kill power to everything every time you stop and resetting your fuel trims. I'm also leery of "disconnecting" the ECM thousands of times since they used to say that there is the chance to cause surges that could damage the ECM.

I don't know if that is a normally open or normally closed relay. If normally open are you going to have the relay drain power every time you leave the vehicle for a few hours or cut it off to kill power? If this was a vehicle that doesn't have ECM and BCM then no problem. If normally closed you will have to keep it powered when you are not using it which defeats the purpose. It's probably normally open.

 

[Dale E]

I use a Cole-Hersee kind on my Stalker Seven. I have the battery in the floor in front of the passenger (were the Goblin should have it for weight and center of gravity). The cables to the disconnect are about 6 inches long and the turn knob is on the side of the car at the top level of the battery. A lot of race cars have them mounted on the hoods just in front of the windshields either on the drivers or passengers side or both.

But I put a second one in under my dash on the passengers side because I was always getting in the car, buckling up the seatbelts, then having to get back out and walk around to the passengers side to turn on the battery. I'm a forgetful old guy - okay!! Actually I have the battery switch, fuel pump and computer switch, then an ignition switch I have to flip before being able to start the car. There is also a key switch hidden that I leave on unless traveling. Way overkill I know!! Theft deterrents!!

Some folks use the Summit remote one you listed and the pull lever is attached to the under dash in front of the passenger. Usually race cars also have an arrow or lightening bolt decal pointing to the switch so the corner workers at the track can easily find it.

Make sure it turns off everything including the alternator.

Search google race car battery disconnect images for types and wiring diagrams.

Dale

 

[mike_sno]

Have you ever figured out a good location? My kids are playing in the car all the time, switch the lights on,... I was thinking somewhere behind the front wheels. Close to the battery. Once the car is parked in the garage, I can cut off the power completely.

 

[Nightmare]

I feel your pain…easy to reach and out of sight.

 

[Ross]

Some racing rules want the battery cut off switch on the outside of the car body, where it can easily be reached by a fire fighter/ emergency response.

 

[Nightmare]

You’re right. I read him saying his kids were getting in the car and playing around, that triggered me, lol. This is definitely a hidden location that would be hard to find if you don’t know exactly where.

 

[duthehustle93]

This won't cover 100% of organizations, but the overlap of most rules is:

The disconnect switch must sever ALL power and kill the car at higher than idle RPM's (usually they have us rev the car to 3k RPM's and show them that it will die). Common points to open to kill the car (using the 3rd/4th terminal on the kill switch) are the alternator, ignition switch, or I prefer some sort of engine/main fuse that typically kills fuel/spark when opened. I haven't gotten to wiring a kill switch into my Goblin yet so I haven't figured out what to tap into.

In terms of placement, most specify that it must be accessible by emergency response and the driver. I prefer to mount it on the left down bar (to the left of the steering wheel, next to our ignition switch) since it satisfies both of these conditions with one switch.

I don't think organizations who would allow an open cockpit/open wheel car run would be strict about (or even require) a kill switch but I could be wrong. Usually it's just w2w where they have any actual tech inspection.

 

[mike_sno]

Yeah, I am less concerned about the racing requirements as more about my kids playing in and on the car. Don't want to see the next drained battery

However, good points! I think somewhere on the driver side reachable from inside and outside might be best. There is a gap between the hood and the side panel. This would hopefully fulfill the racing and kids requirements.

Does anyone know what size the battery cable from the cobalt is? I have some extra cable, but need to buy the correct lugs.

 

[G Atsma]

Actually you could use TWO disconnects in the same circuit.
A hidden kid-proof one to shut off at home but "ON" everywhere else, plus another in a handy spot for emergency shutoff while racing.
Just make sure both are ON before starting up at home...