Latching Relay For Battery Disconnect?

For a '68 Chevy El Camino...bone stock for the moment...

I want to install a battery disconnect feature and its purpose would be twofold: one, the obvious anti-theft use and two, as a simple and convenient way to disconnect the battery for maintenance...seems like I'm always disconnecting and re-connecting, etc.

I do not want to use one of the commercially available products with the big handles...too large and obvious. My search has landed me at the idea of a latching relay with a tiny little hidden momentary switch to activate it one way or the other.

The problem (in my mind) is trying to determine the size/rating of the relay. Assuming I have an Optima 1000 CCA battery, does that mean I need a latching relay rated at more than 1000 amps???

Could I get some feedback on this thought process? Thanks.

you would need a relay rated at total current draw of the car....including during start.

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Where theres is a wire there's a way.

It's going to be difficult to find a relay that could handle that kind of current draw for continuous duty; you might look into just interrupting the branch that goes to the car's electrical system, with the exception of the heavy gauge starter branch.

It should have the same effect, since it's not going to run with only the starter cable connected.

That would cut down on the relay size requirements quite a bit, and put it more in the realm of possibility.

Still, it's a risky thing to do, because a relay failure while you're driving could either shut down the car or fry the electronics-

how do you plan on powering the relay?

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Prove your connections, use a meter!
I promise, I'll behave!

I assume the question of powering the relay was directed to me, so...
I envision the relay sitting right next to the battery with some nice hefty cables running to it, along with a tiny wire to my momentary switch. Also, there would be two or three components that never lost battery power without further intervention: the radio, maybe a clock, and the relay too. So...as long as my maintenance duties did not involve those three circuits, I could turn off everything else, right? And still hit the momentary switch to reconnect the battery when I was through. Does that make sense?

Try https://www.mobi-arc.com/whypgate.htm.

On the question about powering the relay; unless you use some kind of latching relay that doesn't draw any power after it gets switched, you'll end up with a drained battery from the relay power draw. Any relay that can handle current like that is going to draw a lot of power, so you can't leave it energized when the car's not running.

You'd have to switch off the relay every time you shut the car down; don't know if that's what you were intending to do.

A solid state relay that doesn't draw power might do, but those things are going to be $$$.

so you want to use a momentary switch to ground the coil of a high power latching relay to interupt the batteries + cable. which means you'll have to press the momentary switch after you shut off your car to serve its security purpose and press it before you start your car. you have to press it twice. too much work why dont you just install a hidden kill switch? you only have to press that one once, when you want to start your car. and more reliable overall.

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Prove your connections, use a meter!
I promise, I'll behave!

i would just hook up a hidden kill switch on the ignition wire, no power to the coil, no start. The first place a thief ususally goes to is the battery to disconnect it and see your massive relays and wiring. with the hidden switch they wont be suspecting anything

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There are 10 types of people in the world, ones that understand binary and ones that dont.

I realize the advantages of a hidden kill switch in the ignition wiring, but thieves are only part of my issue. Please remember the second purpose of the switch: to conveniently disconnect the battery for maintenance purposes.

Because I tinker alot, I seem to disconnect the battery alot...and...for weight shifting purposes the battery is being moved to another position, mid-car. This is cool except it is very difficult to get to...and there's no reason to get to it except for this maintenance stuff. So...with the relay sitting next to it, no one would ever even think to look for it where it will be, let alone find it...and if I had a tiny activating button in that yet to be determined "convenient" spot, all would be good. Thanks for all the ideas thusfar.