I need to install a battery shut off on my car. I do not race, just DE4 and instructing. So it isn't required. But, the car sits for long periods since it is no longer my DD and the battery is invariably dead when a track weekend rolls around. Don't have a garage so a trickle charger is possible but not ideal. Plus a battery shut off is a safety feature too.

So any recommendations on which one to get? Where to put it? How to install it (for ease of install but also track safety as well)? I'm assuming it is fairly simple and just requires a length of batter cable. Any help much appreciated.

 

Don’t oversimplify this as the install of a kill switch isn’t as simple as cutting and splicing in a switch with a couple feet of 4 gauge. Proper mounting requires not just the cable but suitable mounting materials, devices to fully drain/cutoff battery/alternator, etc.

Back when I raced in SCCA (decades ago), rules weren’t quite as tight but still had specific rules to be followed

Location and types of switch is determined by sanctioning bodies - usually by types of car (say stock body versus framed formula cars, etc), speed potential, and several other criteria.

Even though you “aren’t racing”, would suggest you consult the closest set of rules to the type of use. Would tend to think the SCCA GCR (general competition rules) is a good place to start.

If all you want is to disconnect the battery during “off times” there are “quick release” terminals you can buy just about anywhere. I have one of those but my roadster sits on a Noco tender.

 

You want to cut off power from both the battery and the alternator. I would second what mic said source sanctioning rules and follow the most strict.

 

Thanks guys. As in most things this is apparently more complicated than I first guessed. I will look at the NASA rule set since that's what I'm most familiar with.

I see many at the track mounted outside the car. I'm not really interested in that. Do any of you have one mounted inside and if so,where? (My car currently has the full interior in it from the seats forward. Back is more of less gutted.)

I'm assuming cutting power from the alternator is purely a safety consideration and not anything to do with preserving battery?

 

The reason for cutting power to both the alternator and the battery is the Z will still start if only one is on the circuit. The kill switch on my T3 Z is located on the lower IP of the passenger side. This was a relatively easy location to use, as it's close to the OEM location and the airbags all are gone. There is a identifying decal on the PS door to indicate the kill switch is located inside the cockpit. I'll see if I can find a photo of it.

 

@dkmura Sorry to be dense, but what is the "IP"?

The NASA reg is as follows. Not very specific but confirms everything mentioned here so far:

15.8Master Switch: An electrical master switch is required. It should be mounted so that it is easily accessible from the outside.If mounted outside the cockpit, it should be mounted in an area where it is least likely to be damaged(e.g. cowling near wipers). The switch should shut off the motor and cut all power except to the on-board fire system, radio communication,and any other life support / medical device. The switch location must be clearly marked with a master switch cut-off decal.

So it can be mounted inside as long as it can be reached from the outside.

 

IP= instrument panel. In this case, my 3-pole kill switch is mounted to the lower panel of the passenger IP. It's location allows a corner marshal to easily lean into the cockpit and switch everything off if I'm not capable of doing so.

 

DK, I was instructed (and I actually tried it to win a bet with a buddy) that the car essentially runs off the alternator, filtered off the battery. Essentially, the car can still run with the battery disconnected purely off the battery.

When I foolishly did this the car ran rough and inconsistent but still ran. Once again, this was dumb as the alternator can produce voltage and current spikes and that can damage electrical components ... as mentioned above, the battery acts as a voltage and current filter/regulator.

I'll find a picture of my setup but it's to the right a foot or so of my instrument panel.

I've seen cars run two cut-offs - one in the cabin for the driver and one outside for EMS personnel if a driver was incapacitated and couldnt not cut power after an accident.