Battery Cable Removal/Install Question

[MendingLine]

G'Day. I am really confused because I find two different recommendations for battery cable removal/install order. The first says take the black (neg) off first and then remove the red (pos). The second, which I have always done, is to remove the red (pos) first and then the black (neg). Reverse order for install. Which is correct?

Also, if one is using a portable shore battery charger, do you remove the red (pos) cables and leave the black (neg) attached and charge, or can you leave the cables on while charging if you have a shut off switch for the batteries set to off? Or do you remove all of the battery cables for charging?

Thank you, Gary

[skyranchrob]

You always take the neg. off first, that way when you take the pos. off you will not ground the wrench and complete the circuit. You put the neg. back on last for the same reason and it also prevents the batt. from exploding. Rob

[jenkinsph]

I agree in theory with removing the negative cable first and replacing it last for the same reason posted above.
When attaching a portable charger or using jumper cables it is better if you can attach the positive lead from
the charger to the positive post first and then attach the negative to a ground point away from the battery
this gets the spark if any away from the battery case.

Most of us have permanently installed battery chargers on board which are connected all the time. It is not
necessary to disconnect the main leads while charging the battery. If the key is off and all the electronics
are turned off you should be okay regardless of whether on not you have a battery switch, if you do have
a battery switch you can turn it off to help reduce draining the battery between trips.



Steve

[MendingLine]

Many thanks Rob and Steve. I appreciate your advice. By the way, a local boat shop mechanic told me just the opposite and that is why I have been installing cables in the wrong order. I do not go to that shop anymore for a number of reasons! Cheers, Gary

[Flot]

On a boat it isn't as big an issue as on a car. On a car, you take the neg off first because that way if you accidentally ground out the wrench while removing the positive lead, you aren't completing the circuit. On a car, touching the wrech between the positive terminal and almost ANYTHING will ground you out and give you a nice fireworks show. On an outboard, there's almost nothing you'd hit in the bilge that would be grounded - on an inboard, you'd just be avoiding the engine and other metal components, which may or may not be near the battery.

It doesn't matter which order you put them on or take them off, neither will reduce the chance of spark. If you are able to connect the ground somewhere other than the terminal itself, you can reduce the risk of sparking near the battery - however that may not be an ideal connection as you'll have increased resistance.