Which cable should i dissconnect on my car battery when its not running to stop something from draining it?

Question

My battery drains when my cars off and its not the alternator, should i take off the pos or neg to save energy?

Answer 1

Disconnecting either one will prevent the battery from draining; HOWEVER- always disconnect the negative (black) first.
If you accidentally contact some metal part of the car with the wrench while attempting to disconnect the positive terminal FIRST, you will cause a massive spark and the battery could explode.
If the negative is disonnected first, there's no chance of blowing yourself up (unless you actually short the two terminals together).

Answer 2

A alternator can! Drain your battery. In most cases it's not charging. But I have seen alternators drain a battery over night. Hook up a volt meter to it and start the car. You should get 14 volts. That's normal.if you get 15 or more volts. Or if you don't get any volts it's bad. You can also load test the system just by turning all your lights and a/c. If you don't hold 14 volts it's time to change. But in some rare case's. I have seen a alt. Drain a battery when the car is off. For some reason. After the car is turned off. The alt wants to spin backwards drawing from the battery. All you need to test for that is hook up one side amp meter to the big charge wire on the back of the alt and the other to the feed wire. If you show any amps. It's drawing. The same can be done with a starter as we'll. Over the last 35 years as a tech. I have seen both. So the answer is YES!..

Answer 3

For your own safety Disregard COMPLETELY the answers that say to disconnect the power, Red, or anything BUT THE NEGATIVE lead first. Any other answer will lead to a short if you touch the car in any way with a wrench or even you sweat from the power or positive lead.'
Again,,NEGATIVE LEAD ONLY FIRST!!!!
If you cannot or must do this on a regular basis, you can buy a battery disconnect switch that is much safer than removing the wires.

Answer 4

In the U.S. you always disconnect the Neg terminal first and then the positive. Disconnecting either terminal will keep your battery from draining, but you are less likely to hurt yourself if you disconnect the Neg. terminal first. When connecting a battery it's the opposite. You connect the Pos terminal first and then the Neg terminal.

Answer 5

best thing ot do would be to find whats draining the battery...
have you check the light in the trunk to make sure it goes off when the trunk is shut....
Thats the usual thing to look for...
Next... check your brake warning light in the car. Leave the car then go back look inside and see if that little brake warning light is on...( this happend to my wifes car a mercury sable even though there was enough fluid in the brake res turned out to be a faulty switch.)
Also check light in the glove compartment... that could be staying on.
Same under the hood check to see hif the hood light is staying on... its a lot less hassle than keep looseniong a battery connection...........

Answer 6

Negative

Answer 7

just a suggestion, but if this happens alot and you want andeasy fix. buy a battery cut off switch and mount it so you can reach over the tire inside the fire wall and cut the juice. all you have yo do is cut the hot wire and connect the switch.

Answer 8

When disconnecting a battery you should always disconnect the RED first, then the BLACK and do the reverse when putting them back. By doing this you prevent the chances of spark and the possiblity of any short of shock to the car.

Answer 9

Grab both posts and take the cables off both of them simultaneously, if you don't do them simultaneously the battery will short out and cause a fire.

Answer 10

Disconnect the hot wire.
The neutral is attached to the block or other metal part of the car.