Jump starting a boat motor

[sterlingcaster]

I have heard two different stories. Some say never jump a boat with a dead battery. It supposed to screw it up pretty bad. On the other hand some say it is ok. I got one of those battery pack jump starters for xmas and it says you can use it on boats. Whats the truth?

[Crossroads]

I've jump started outboards with no problems. There's always a possibility that the vehicle sourcing the power whether its a car or boat can overload alternator diodes. But jumping from a non-running vehicle or just a battery shouldn't pose a problem for the receiving engine.

[Redfishr]

Iv'e jumped it from my trolling motor bat to my motor bat, no problem.

[CHunter]

Shouldn't be a problem but if your battery is down in a compartment with gas fumes be very careful, I would put the cables on the dead battery 1st, then connect to the live battery outside your compartment. I would attach my ground cable from the live battery to a ground somewhere besides the battery itself(in case its frozen, which I doubt would happen down here). Charging a battery puts off hydrogen gas which is very flammable. Turn your blower on or make sure you have the compartment door open all the way when removing cables, the cables can cause a spark, remove the positive side 1st. Be wary what can happen, even though everything will probably be okay.

[CHARLIE]

Its no problem jump starting your outboard. What happens is people cross the polarity and that will blow lots of things up. Always be sure positive to positive and negative to negative.

Charlie