I have a small boat (MacGregor 26M) with a Honda 50 outboard engine.

Needless to say I have a battery for it... plus two house
batteries. I also have a throw switch (or whatever it is called)
allowing me to use just the Honda battery... or the two house
batteries... or all... for my DC electrical needs.

When motoring with the Honda is it okay to use the "or all"
mode to charge the aformentioned batteries... or would it put
a strain on it's alternator.

So far I have been using the "one battery" mode (for the Honda)
when operating the outboard engine. I have a marine charger that
I use for the house batteries when hooked up to AC shore power.

Since I motor quite a bit... I would like the option to charge all
batteries providing it isn't a strain on the Honda alternator.

Thanks for your help..

Best regards

Bill

On 7 Sep 2006 09:07:04 -0700, wrote:

When motoring with the Honda is it okay to use the "or all"
mode to charge the aformentioned batteries... or would it put
a strain on it's alternator.

No problem, the alternator is self limited. It's not a good idea to
operate the switch with the engine running however, because *that* can
cause alternator damage.

No problem, the alternator is self limited.

Thanks Wayne for getting back to me on this particular
thread.

Your comment is encouraging... in that my little boat is
not that often near an AC power source where by I could use
my marine battery charger... in a conventional manner.

Also tnx for the heads up relative to switching configuration
modes while underway and motoring. I had all ready read some-
where that this was a "no no" or bad things could possibly
happen. (smile)

Cheers...

Bill

I'm curious : is the charging mechanism of this motor considered an
alternator (would it indeed be damaged switching batteries) ? I think the
Honda 15 I had, which actually had a higher amperage than the 50, just had
what I thought were magnets in the flywheel. At least there was no
alternator that i would recognise.

"Wayne.B" wrote in message
...
On 7 Sep 2006 09:07:04 -0700, wrote:

When motoring with the Honda is it okay to use the "or all"
mode to charge the aformentioned batteries... or would it put
a strain on it's alternator.

No problem, the alternator is self limited. It's not a good idea to
operate the switch with the engine running however, because *that* can
cause alternator damage.

On Fri, 8 Sep 2006 20:30:23 -0400, "Garland Gray II"
wrote:

I'm curious : is the charging mechanism of this motor considered an
alternator (would it indeed be damaged switching batteries) ? I think the
Honda 15 I had, which actually had a higher amperage than the 50, just had
what I thought were magnets in the flywheel. At least there was no
alternator that i would recognise.

If it has diode rectifiers that convert AC to DC, it can be damaged by
switching batteries.

Wayne.B wrote in
:

If it has diode rectifiers that convert AC to DC, it can be damaged by
switching batteries.


How do you think that would happen? The stator windings limit current and
the rectifier is rated much higher than they can produce. There's no
reverse voltage over 14V so that's not a threat to a rectifier, either.....

What IS threatened is the ELECTRONICS hooked to the battery switch if the
electronics is hooked to the alternator side of the switch. In moving the
switch, if the battery circuit opens, the stator/rectifier puts out its
open circuit voltage (engine running of course) and that voltage is much
higher than the 14V of the batteries, possibly getting high enough to
destroy the bloat-priced electronics hooked to it. Of course, if your
electronics is directly connected to the house batteries, that's not a
problem, but this would be unusual.

The charging alternator isn't threatened at all....unless the battery
switch has a short to ground, which might take out the rectifier. Battery
switches don't have grounds in them.

--
There's amazing intelligence in the Universe.
You can tell because none of them ever called Earth.

On Sat, 09 Sep 2006 06:16:01 -0400, Larry wrote:

If it has diode rectifiers that convert AC to DC, it can be damaged by
switching batteries.


How do you think that would happen? The stator windings limit current and
the rectifier is rated much higher than they can produce. There's no
reverse voltage over 14V so that's not a threat to a rectifier, either.....

That's contrary to my experience and that of *many* others. If you
momentarily remove the load on the alternator, a voltage transient is
created that exceeds the PIV rating of the diodes and they fail faster
than you can talk about it. It happens all the time.

Wayne.B wrote in
:

That's contrary to my experience and that of *many* others. If you
momentarily remove the load on the alternator, a voltage transient is
created that exceeds the PIV rating of the diodes and they fail faster
than you can talk about it. It happens all the time.




A 2.5KV PIV diode costs the same as a 400 PIV diode. They'd be crazy to
put in one too small. We're talking about an ALTERNATOR, not some DC
generator. It has no regulator, just its own resistance. I'd love to see
one fail. I've never heard of it failing...well, except when some boob
idiot shorts out the battery....overcurrenting the diodes, I suppose.

Hmm...very interesting.



--
There's amazing intelligence in the Universe.
You can tell because none of them ever called Earth.