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I'm ready to install a battery disconnect switch and was wondering what everyone else has already done. Where did you install your battery disconnect switch and which one did you use?
I'm ready to install a battery disconnect switch and was wondering what everyone else has already done. Where did you install your battery disconnect switch and which one did you use?
I'm ready to install a battery disconnect switch and was wondering what everyone else has already done. Where did you install your battery disconnect switch and which one did you use?
Yes, a knife switch to the negative terminal. There's a screw-**** style that I used for quite a few years and ended up not liking it because it was fiddly in use. The knife style is simple and obvious when it's open or closed.
Got what looks to be the exact same knife style disconnect on ebay for like $10.
I did need to run a 3/8 X 16 tap through the metric threads tho and use my own bolt. 12/24V Car Battery Disconnect Knife Blade Switch Side Post Heavy Duty Shut OFF | eBay
Seems that a lot sold on ebay use metric threads. Note the 8.8 on the bolt head.
Correct tap fixes that.
I still like the fiddly ****, and don't like the knife switch. I used this one, and needed to buy a metric EDIT: slightly longer bolt for the battery. OOS at Amazon, perhaps something similar is available.
I'd probably use a Blue Sea Systems switch if I didn't mind drilling a hole in the storage door.
Last edited by Bikespace; Jul 29, 2025 at 06:28 AM.
I still like the fiddly ****, and don't like the knife switch. I used this one, and needed to buy a metric bolt for the battery. OOS at Amazon, perhaps something similar is available.
I'd probably use a Blue Sea Systems switch if I didn't mind drilling a hole in the storage door.
i thought the side-terminal battery bolt was a short 3/8-16 ??
maybe i been using the wrong bolt all these years.
Don't like the **** switches at all. Awkward to use and sometimes a poor connect/disconnect feature. Your choice.
I have these on all my cars.... several for 20+ years. Seem to work very well and easy to use.
Seems some put on neg terminal and others on positive. Any considerations on which way to do it?
Negative terminal is best practice.
It may not matter so much in the fiberglass battery compartment of a C3, especially if you aren't using any tools, but under the hood of a truck, for example, the positive terminal can be a hazard. Especially with all the metal in a knife switch.
I have been using Marine Circuit Breakers that work really well as both a switch or a circuit breaker. I have it on the negative line near the battery. It takes nothing to open the switch and it is even water proof/resistant so it works well in older C3's.
You need a fuse as well as a switch so why not do both with one device which is water resistant to boot?
Mine's on the positive terminal because it fits better there than on the negative terminal.
No spark ever seen,,,,, even with a door open and the interior lights energized when the switch is closed. I suppose having a brief spark makes sense, but I never worried about it. I have several cars with the switch on the positive terminal, but all the others have the battery in engine compartment so nothing is energized when the switch is closed other than the clock. Many years with this practice.
Got what looks to be the exact same knife style disconnect on ebay for like $10.
I did need to run a 3/8 X 16 tap through the metric threads tho and use my own bolt. 12/24V Car Battery Disconnect Knife Blade Switch Side Post Heavy Duty Shut OFF | eBay
Seems that a lot sold on ebay use metric threads. Note the 8.8 on the bolt head.
Correct tap fixes that.
Wasn't that just a pain in the butt! Buncha crap............... But knife style is great: lift up, push down. EasyPeasy
battery disconnect switch
