forget the charger

[Fou Du Large]

This afternoon i started my motor for the first time of the season and my battery charger was ON...
The motor runs about 5 min. at low speed.
Is it dangerous for the charger or alternator?

Thank you!

[Stu Jackson]

No, it should not be a problem for your charger, alternator or batteries.  Both the alternator's regulator and the charger were "seeing' whatever state of charge the batteries were in, and acted accordingly.

It's just not a good thing to do on a regular basis.  No need to be plugged in if you're going to go sailing.

OTOH, there have been times when I was changing engine oil, had the shorepower on, and cranked the engine, as an example of when that occurs.

[Ron Hill]

Guys : Batteries like to be charged, but NOT from two differant sources. 
Just remember to flip the shore power switch off (when you're plugged in) before you start the engine.  You might get into trouble if your batterys are down and you do that.  Otherwise with charged up batteries everything should be OK.   

[Norris Johnson]

Some chargers will trip out when ever you start the engine with the charger in service. My old FlyBack 20 would trip. The reset procedure was to disconnect the neg. wire on the battery for 3 mins. I've got into the habit of shutting off my Statpower before starting the engine. I don't know if it would trip. Never tried it.

[Fou Du Large]

Thank you all.
I will be  more attentive next time.

Bye

[Randy and Mary Davison]

I've probably left my Statpower TruCharge on a dozen times for a few minutes each time with no apparent effect.  The regulator is a Balmer.  Whether it causes problems is probably equipment specific.