Backup regulator

[John Langford]

Has anyone ever identified a cheap automotive regulator that can be used as a short term backup if the "smart" external regulator packs it in while on a cruise and far away from a marine electronic store?

[Stu Jackson]

John,

I've been thinking along the same lines for quite a while, and have come to the conclusion that perhaps the easiest thing to do would be to purchase a backup least expensive Balmar or Xantrex.  In doing the numbers, even if I could find or buy something along the lines of what you're asking, it'd probably cost around $100, less if you could make it yourself.  What I'm suggesting is about $150 for the basic simple plug in, to the back of the alternator, plus the front side of the regulator.  A true swap out, easy, plug and play.  That's just the way I've rationalized the investment side.  The least expensive of their regulators usually puts out a constant voltage, enough to get you home or to a plug in once a week to replenish the steadily diminishing law of charging with that type of regulator.

I'm all ears for another solution.

Great question.

[Tom Soko]

John,
What about the original "internal" regulator that came with the alternator?  When I took mine off to attach the external regulator, I labeled the wires and packed it up in a plastic bag.  I keep it on the boat for just the scenario you talk about. 

[wind dancer]

Another suggestion, only viable at the time you're replacing your alternator, is to purchase one with a built-in backup such as the Balmar 6-series alternators.

[Stephen Butler]

Perhaps a silly question, but how often does a regulator fail?  Does anyone out there know the mean time to failure for this component?  Perhaps it would be better to replace every few years, rather than keeping a spare aboard...as is done with composite timing belts on some cars.  Just a thought and a question.

[Craig Illman]

John & Stu -

I would agree that the mean time between failures is probably pretty low. If I was going offshore, I'd take a spare internally regulated alternator. I think the alternator, with it's moving parts, is more likely to fail than the solid-state regulator, baring any lightning strikes.

Craig

[John Langford]

A regulator fails most often when the absent-minded skipper turns the battery switch to off while the engine is running. I haven't done it since 1975 but I am due and I don't have a zap stop installed. Perhaps that is what I should do!

The previous owner swapped alternators so I don't have access to the original internal regulator or alternator.

Thanks for the thoughts everyone. Very helpful.

[Ron Hill]

John : You can use almost any cheap automotive regulator - it's getting it wired in properly that's the trick!!
If you have a Balmar Alternator you can use a Ford truck regulator.  I've been carrying one on the boat for about 18 years and have yet to need it!!