Re: How to know if engine is charging battery?
The really sure way is to connect an ammeter in series with one of the battery connections, but NOT if you are starting the engine electrically (You don't say what the engine is !) If you are then the ammeter will have to go in series with the output of the rectifier.
It is easier however to do as SgtMaj suggests and connect a voltmeter, or a multimeter set to the 20V DC range, across the battery. It should read something like 12.6 or 12.7 if the battery is fully charged and been "resting" for 12 hours or so. You'll see the volts fall well below that figure while the engine is cranked on an electric starter but it should then rise again quickly if the battery is being charged to something over 13.6. To get the battery fully charged (or at least to about the normal 80-90% of fully charged) you've got to see it rise to around 14-14.4 volts
