Battery Isolator/Kill Switch

[Davemg]

Just considering installing one of these on my Quantum Xtreme;

https://www.demon-tweeks.com/longacre-b ... mic_728x90

(Demon Tweeks LON45788)

Has anyone any experience of them?

[David T]

I've got the Sytec equivalent and it works well.

[Tony C]

Wouldn't be without a battery cut-off, fitted one to all my kits, I went for the removable key option, something like this with aux contacts for ignition and alternator protection resistor; https://www.jjcraceandrally.com/race/ba ... minal-base

[Davemg]

Thanks, looks like I have a little project on the go!

[jeffw]

FIA switches are great on race cars but have a habit of failing/having faults.

Something like this
https://www.autoelectricsupplies.co.uk/ ... ategory/30 is more robust but has the disadvantage of not being quickly switched over.

[steve m]

I have exactly the same one as Tony c, and never had an issue with it, I also bought a spare key, just in case

The one that Jeff showed is good, but certainly on my 7, getting unstrapped, and out of the car, opening the bonnet, to get to the battery, or the other way round would be a real PITA

steve

[jeffw]

If the intention is to isolate the battery while the car isn't in use then the one I send you is the one. If you intend to have something to isolate the electrics in an emergency other than a key then a FIA switch is the thing to go for.

[steve m]

I do hope this isn't getting into a war of which is best .............

As it really is up to the OP to decide which suits his needs the most

[Davemg]

It is intended for emergency use and also as an extra anti theft aid or delay tactic. The plan was to mount I just behind the nearside front wheel, recessed into the body, but not a key version.

In my mind is a nightmare scenario where the relays I use to operate the starter weld together. I have one which is operated by the ignition switch and another by a start push button.

That aside, it seems a prudent and sensible thing to do.

[Davemg]

Finally got to doing this over the break.

My son was concerned that by putting the switch on the outside of the car, I made myself a car jacking target. He has a point, although the area we live in is generally ok.

To get round this I fitted two relays. The effect is that the Kill switch is bypassed with a 50A fuse on both its poles - one is (will be) in series with battery negative, and the other with alternator positive. This means;

* If the engine is not started, then the kill switch works as you would expect.
* If the engine is running or ignition is on, the kill switch will not kill it unless the ignition is turned off as well. I know it slightly defeats the object but how many of us do not turn off the ignition in response to a problem?
* You can't crank the engine with the kill switch off, as the 50A fuse will blow.

I have relays controlling the solinoid, so if they weld together I can kill the whole thing. In addition, I have a quick release steering wheel that blows the horn fuse, so again, problem solved as when I park up, I can turn off the battery if I want to remove the wheel.

Just realised I didn't need the double pole switch if I was using a relay for the alternator which is energised by the ignition. Damn!

Hope that all makes sense...