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willyt
05-24-2011, 03:30 PM
Ok, sorry for ANOTHER alternator thread, but the dealership just replaced my alternator in my 2005 X2 with the MCX.

As far as I know, the alternator was put in at the factory. 6 years on a new alternator seems like a pretty short life. Iím not running a crazy huge stereo or anything. Why did this puppy go bad? Anything I can do to prevent the new one that was put in today from going bad?

chawk610
05-24-2011, 03:49 PM
The alternator on my boat JUST went bad... but it was 28 years old!!!!! 6 years isn't that long for sure. Do you store your boat outside? Or in the garage?

JimN
05-24-2011, 03:56 PM
Ok, sorry for ANOTHER alternator thread, but the dealership just replaced my alternator in my 2005 X2 with the MCX.

As far as I know, the alternator was put in at the factory. 6 years on a new alternator seems like a pretty short life. I’m not running a crazy huge stereo or anything. Why did this puppy go bad? Anything I can do to prevent the new one that was put in today from going bad?

#1- If the boat will sit for a long time, disconnect the battery. Next best is to use a battery tender, not just a trickle charger, which won't shut off.
#2- if you must jump start someone elses' boat/car/truck, shut your engine off. A dead battery is a heavy enough load for an alternator but when you add cranking an engine to the load presented by your engine & the dead battery to an alternator that's rated for less than 100A, the regulator won't survive. It takes 150-350A to crank an engine with the starters used in these engines, depending on condition, temperature, discharge state of the battery and other factors.
#3- If the battery dies, don't jump start it and use the alternator to recharge the battery. recharge it fully before running it.
#4- If the battery dies, don't let it sit for long in that state and if there's any chance of the battery dying in freezing temperatures, don't let it happen.

Each time a lead/acid battery dies, it loses about 30% of its capacity. This means that not only will it die faster under load, but just starting the boat discharges it more than a battery that has never discharged. This adds to the alternator's load and causes the alternator to get hotter, which shortens its life, considerably.

chawk610
05-24-2011, 04:15 PM
Jim... are Optima blue tops Lead / Acid?

willyt
05-24-2011, 04:24 PM
Store it inside, and left the battery disconnected during the winter. That's really interesting info about jumping... i'll definitely have to remember that.

I typically don't kill the battery, and if i do i dont let the alternator recharge it.

JimN
05-24-2011, 04:49 PM
Jim... are Optima blue tops Lead / Acid?

No, they use a gel- their website will describe the construction better than I can.