Best battery cut off switch?

[DMC-Ron]

Help me understand the wiring there: when the cap is closed, is the battery engaged or disengaged? Would be better if cap closed = battery engaged and operational in my mind, if you bump the switch, the cap itself ensures it will remain functional. It is, after all, a quick-disengage cap on that switch. You can move the switch by closing the cap. Visual indicator for industrial use is where the red ones see wide use as a kill switch for machinery.

Shep, very astute observation. I modified the safety cover (cap). Normally these caps hold a toggle switch in a specific position when closed. I routed out some material in the safety cover so that the toggle switch would remain in its neutral center position with the safety cover closed.

I hope I answered what you were asking. If not, here is a more detailed general description but I think you already know all this:


So the relay is a latching relay. In this version the coil terminals are [I] and [S]. If you momentarily put +12 at [I] and neg at [S] the relay will connect the battery. When the voltage is removed from the coil terminals, the relay remains in its last state (connected to the battery) because it is latching. No power is required to keep the battery connected. When you momentarily put neg at [I] and +12 at [S] (reverse the polarity) the relay will disconnect the battery. Again, the relay latches so no power is required to keep the battery disconnected.

The toggle switch I selected is an [ON(momentary) - OFF - ON(momentary)] switch, meaning that the toggle is spring loaded to return to the center position and you flip it up or down to provide a momentary electrical connection. The safety cover flips down over the toggle and prevents it from being "toggled" either direction. When you want to connect or disconnect, you lift up the safety shield (it's spring loaded and will stay up when lifted). You then have access to the switch to connect or disconnect the relay. When you're done you flip the safety shield back over the toggle to prevent any accidental activation.

Hope this helps.

Alan Shepard needed this for the explosive bolts.

Ron

[Shep]

Shep, very astute observation. I modified the safety cover (cap). Normally these caps hold a toggle switch in a specific position when closed. I routed out some material in the safety cover so that the toggle switch would remain in its neutral center position with the safety cover closed.

Do you have a picture of the switch when the cap is closed? I absolutely love this idea, and though I don't have a use for it yet, I'll see if I can modify a switch that same way so I can pull it out of a parts box when I come up with a use for it later. This is absolutely brilliant.

(Also blame me for reading too fast and glossing over the part where the switch itself had to be swapped out underneath the cap, which was obvious if not outright stated previously and I missed it)

Alan Shepard needed this for the explosive bolts.

What does my gramps have to do with this?

(Seriously though, that is his name, if only slightly misspelled -- no relation)

[David T]

Switch covers like the one used are used commonly by the military to prevent inadvertent activations. You would not want to accidentally fire explosive bolts at the wrong time. The theory is it takes two purposeful acts done in the proper sequence to activate the switch. Reduces the chance of bumping the wrong switch and, makes that particular switch more important. In some cases opening the switch cover can set off an alarm.

[DMC-Ron]

Do you have a picture of the switch when the cap is closed? I absolutely love this idea, and though I don't have a use for it yet, I'll see if I can modify a switch that same way so I can pull it out of a parts box when I come up with a use for it later. This is absolutely brilliant.

(Also blame me for reading too fast and glossing over the part where the switch itself had to be swapped out underneath the cap, which was obvious if not outright stated previously and I missed it)

What does my gramps have to do with this?

(Seriously though, that is his name, if only slightly misspelled -- no relation)

Shep,
In my original post 36, photos 3, 4, and 5 show the switch with the safety cover closed. The followup post 39 shows the switch with the safety cover lifted.

Ron

[BABIS]

here's my approach with the battery latching relay:







the relay is controlled by the keyless entry remote (2 buttons required to unlatching operation, 1 to latch)

[Michael]

55wx8f.jpg

[CFI]

55wx8f.jpg

Ha! Love it. I have a battery disconnect but I’ve never needed it.

[Bitsyncmaster]

I've seen some solid state battery relays from $150 to $500. I'm concerned about the inductive spikes from the starter causing a failure of these. But I would guess that $500 one has found a way to fix that.

[mark w]

I use one of these. it serves as a switch and protection of the circuit from the battery to the starter.

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

[kinvilje]

This is what I installed. Great for parking lots if you are worried about your car’s safety. I just reach behind the carpet (behind the passenger seat) and flip the switch.