I searched "battery kill switch" and "battery cutoff switch" and nothing came up.

I know they are primarily used for track safety purposes, but I'd like to install a Hella battery kill / cutoff switch on the battery in the engine bay

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Primary reasons:

1. Turning the switch off sure beats unhooking the battery terminals anytime I want to tinker on the car.

2. Installing a switch should extend the life of the battery post and clamps by not having to remove and re-mount each time I thinker (some times multiple times a week).

3. Another line of anti-theft defense for when parking in public.

Are there are reasons why I shouldn't install a switch?

Just want to make sure I'm aware of potential downsides. Thank you in advance for your input.

I have this one installed on the pumpkin.

Mostly for anti theft whilst driving around Medford (aka Methford) Oregon.

Easy just unscrew the know and put it in your pocket or pack.

Also for when working on car.

https://www.oreillyauto.com/detail/c/bliste...t+off&pos=0

I have these on all my vintage cars. My main purpose is protection against electrical fires. I read an article where someone had a vintage car that shorted to ground at some point when in the garage and the whole garage burned down and almost took the house. When you have cars that are 50-60 years old, you never know when an old wire may suddenly short, even if the car has been fine for many years.

I use mine all the time. Works really well and I feel safe both for the car and my family in an attached garage

I have been putting Hella battery cutoff switches in my cars for 50 years. When I park my car on the street, I turn everything off with the switch, take the red key out of the switch and never worry. Also, I don’t drive my car every day and turn off the switch when I put the car in the garage. Highly recommended.

I've tried both types in this thread. Both work very well. They are also excellent if your car has a very minor parasitic draw. I mounted mine in the side vent because I didn't want to drill through the sheet metal.

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I have one installed where the cigarette lighter was that disconnects the negative ground. I had a misterious drain on the battery.

Same here. Works great. Also have a inline fuse for the fuel pump. I remember a lot of discussion whether to use a two pole or the four pole. Less chance of frying alternator with the four pole. Best, MarkClick to view attachment Click to view attachment

While not a theft protection, I installed a 1 in 4 out fuze block so every circuit is fuzed.
I sleep well at night

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Thanks everyone for the input.

I would love to see more pics - especially those that have different locations/configurations than what has already been shared.

Mine

Is there plexiglass aircleaner tops there???

Kevin

So,
I have an 8 year old lead acid battery I just replaced.
I had it on a charger, sitting on concrete, for a few days.

I went to move it, after unplugging and disconnecting everything.
I moved it about a foot, it gave off a big ass puff of smoke.
I touched the outside, it was too hot to touch.

I walked it outside.

Just adding that even trickle charging can create risk.
Three others are fine...

Rich

Yep; all three reasons. I use a simple marine battery cutoff right on the ground terminal. Remove the knob when out or it’s parked in the garage. The clock is hard wired to the battery which puts a constant drain.

kevin, yes it is plexiglass ran through a router....very slow. Worked well, not cracks and good for the last two years. Mark

It's not a bad idea for the reasons mentioned above. Just be sure you don't try to shut off a running engine using a 2 pole cutoff. The alternator will keep the engine running, and fry its own diodes with a voltage spike once the battery is disconnected from the circuit. There's no issue with a 2 pole switch as long as you don't do that.

might have been because it was sitting on cold concrete.
i've heard that is very bad to do to a battery.
we sit them on a wooden table to store them at the workshop.
leave em on the concrete floor and total death ensues.

never had a problem with a trickle charger in all the years of using one.
20 years at this point.
but am more circumspect with harder charging.
don't leave batteries hooked up to a quick charge unattended.


i just have one of these.
same thing in the end?
but not as quickly and easily accessible i guess.
got to flip the engine lid.
funny enough my 914 is my only car that doesn't draw current idle.
never drains its battery. even though it probably only gets started and driven once a fortnight most of the time!

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Yep; that the same disconnect I have. Always park it on four carpet remnants, fiber face down. Keeps moisture off from concrete - maybe a factor?

Anyone know the model# for the Hella four pole unit. I looked at a couple places that offered a Hella unit but did not mention this feature in their descriptions, thanks.


.

Unfortunately Hella don't offer such a cut-off switch. The only four-pole (ie, alternator-friendly) switches are made by companies such as Autolec, etc.

Pegasus and Summit racing has the four pole.