Installing battery switch \\\ What the heck???

[CosmickGold]

I tried to install this cutoff switch on my engine battery as shown. But....



When unscrewed a little to disconnect the circuit, the electrode connected to the wire can easily float up and touch the metal of the control screw, making contact again.



I must be seriously misunderstanding something, because they wouldn't be selling a switch so totally unreliable. Can someone fill me in on where I must be "brain dead" about this?

 

[Ripper238]

Why would it float up and touch the metal of the control screw? The connection is made with the bottom of the green/black knob touching the base when screwed in.

Looking at your 1st picture its solidly mounted to the battery terminal and pressed against the body of the battery so noting should "float up". Is your battery look exactly the same as that photo?

 

[CosmickGold]

Why would it float up and touch the metal of the control screw? The connection is made with the bottom of the green/black knob touching the base when screwed in.

Looking at your 1st picture its solidly mounted to the battery terminal and pressed against the body of the battery so noting should "float up". Is your battery look exactly the same as that photo?

The first picture shows it in the "On" condition; no problem there at all. The screw makes electrical contact with the lower metal part by staying crewed into it all the time, and makes contact with the upper metal part by being screwed down tightly against it.



In this third picture, you can see the white insulation that prevents the threads of the screw from touching the upper metal it goes down through. But as shown in the second picture, that upper metal is not attached in any other way except by this screw; so when the screw is not tight, neither is the upper metal. I held the switch in my hand and wiggled the parts while it was supposedly "turned off", and found that the upper metal part is then loose and can easily touch the screw's base even by swiveling up or down where it's only one edge of the metal that touches the screw.
How is this "short circuit" supposed to be prevented?

 

[kklowell]

I see what you're concerned about I think. Your worry is that because the knob's screw stays loosely threaded into the piece that stays connected to the battery it would be easy for the other piece to get moved enough to maintain contact with the brass on the part of the screw that is under the knob. Correct? I personally think that it looks like it could be an issue, but maybe it really isn't?

 

[AmargosaWayne]

Isn't it easier to skip the extra hardware, adding an unnecessary point of failure, and just disconnect the ground cable from the battery?

That's the method I have used for several decades.

 

[kklowell]

Those side terminal battery threads are wicked easy to strip.

 

[CosmickGold]

I see what you're concerned about I think. Your worry is that because the knob's screw stays loosely threaded into the piece that stays connected to the battery it would be easy for the other piece to get moved enough to maintain contact with the brass on the part of the screw that is under the knob. Correct? I personally think that it looks like it could be an issue, but maybe it really isn't?

You are correct about that being my concern. And by moving the switch around in my hand, I found that the "short circuit" can easily happen.

Isn't it easier to skip the extra hardware, adding an unnecessary point of failure, and just disconnect the ground cable from the battery?

That's the method I have used for several decades.

I wish it was that simple. But my battery is tucked down under one of those tiny little hoods that don't even show the engine. The terminals are on the battery's backside, so to get to either of them, I must unstrap the battery and tipped it up and toward me, and then hold it there while using a specific wrench to take out the center screw which is a long one. (Whew!)

Given a choice, I like the idea of turning a little switch a lot better.

 

[kklowell]

I use a switch to disconnect my house battery from the vehicle battery but it's a rotary switch that I installed inline with a 50 amp fuse. When it's in the off position it's off and not going to get jostled back on.

 

[user 423]

They sell a knife-type cutoff switch but then it sounds like access to your battery is pretty tight:

https://shop.advanceautoparts.com/p...V5Do4Ch0AVwF8EAQYBCABEgJvR_D_BwE&gclsrc=aw.ds
Are you having problems with battery drain?

 

[CosmickGold]

HEY GUYS! --- I found the answer!!!
The two metal sections each have two tabs near the center that press in over the white insulation and into indentations on the other metal section, holding the switch together very securely.



The tabs are very tough to bend, but that's obviously a good thing, making the unit strong. I used a pair of vice-grips to bend them.

Obviously, the manufacturer should have pre-bend them to secure the switch; or at least sent a little paper of instruction along with the switch.

 

[Ripper238]

Glad you figured out a way to make it work.

The way it looks when the terminal bolt is tight to the battery its supposed to hold/sandwich the whole switch (bottom and top) to the body of the battery so they wont come apart.

 

[Matlock]

The negative reviews tell the true story of this product.
Save your money. Wrench off the negative wire from the battery and your done.

 

[CosmickGold]

. . . The way it looks when the terminal bolt is tight to the battery its supposed to hold/sandwich the whole switch (bottom and top) to the body of the battery so they wont come apart.

Yes, this works perfectly when tightened down, exactly as you said. But the way to turn the switch "off" is to loosen that bolt, and then the problem happens.

The negative reviews tell the true story of this product. . . .

YOU DID YOUR HOMEWORK! So many people trudge forward without a plan, without checking things out ahead of time. You do it right, saving yourself a lot of grief. (I "trudged", I didn't read.)