Battery Disconnect

As far as I know you should always hook up the switch to disconnect the positive.

Another vote for positive.

On going thread right now in Tech Issues section of the Forum.

westend wrote:
On going thread right now in Tech Issues section of the Forum.

An enthusiastic discussion.

Negative

Electrically wise there is no difference. Only a choice of convenience. In my case all of my multiple batteries NEGATIVE TERMINAL goes directly to frame ground an I use four position BLUE SEA battery switches in the POSITIVE path. These become my BATTERY DISCONNECT when I select OFF on all my BATTERY SWITCHES.

In my automotive battery layout it would be best to have the BATTERY DISCONNECT switch in the NEGATIVE PATH so that when you open up the circuit while removing battery terminal cables you DO NOT have to worry about your wrench touching close proximity grounded items. With the NEGATIVE PATH OPEN there will not be a circuit path to ground to cause sparking.

The best is to break both connections. If that's not an option break the pos side. If you break the neg at the battery you leave the whole unit with potential should you inadvertently create a ground connection.

bguy wrote:
The best is to break both connections. If that's not an option break the pos side. If you break the neg at the battery you leave the whole unit with potential should you inadvertently create a ground connection.

No. It's not possible to inadvertently create a ground connection as nothing is a ground unless you create a path directly at the neg batt terminal. If you use a knife switch type (with lots of bare metal) the only place to safely use it is on the ground cable.

What if you have 4WD, doesn't that change whether you put the disconnect in the positive or negative?

Too many TLA.
4WD??? 4 wheel Drive???