electrical probem

[nissan789]

Hey Ive got a 89 hatch and today my stepdad and I were going to take a spin in it. The battery somehow died,( worked a week ago) and we had to swap one out of his maxima. Then it turned on fine. When we got back home we did some work and had to park it in the garage and it look about 4-5 knocks for the motor to turn on, not normal. We think somethings draining the battery and somethings wrong with the alterator. any help? thanks

[vancouverbc]

Alternator test using volt meter:1.turn headlights on for 15-20 seconds to remove surface charge2.measure voltage across battery when engine off3.turn off all electrical loads ie wiper ,etc4.start engine and increase speed to 1500 rpm5.measure voltage across battery with engine steady at 1500 rpm

the voltage reading should be at least .5 volt higher with engine running. if voltage goes up more than 2.5 volts, alternator overcharging.

You can also test with engine running with lights on at 2000 rpm. the voltage should increase at least .5 volts