battery charging question

[ricmin]

Hi everyone, first post to this site although I have been lurking for quite some time.<br /><br />My problem is this; I have a 85 90hp merc that does not seem to be charging my battery. was out fishing and battery was fine although I noticed the battery gauge was not getting above 12 volts even when running WOT. Next day battery was dead, replaced battery with new one still not going above 12 volts and seems to go down when engine is running, then goes back up to read 10-12 when engine is off. I recently replaced the ignition switch, could this have anything to do with my problem or are ignition and charging sytems 2 different animals? Thanks in advance<br /><br />Rick

 

[ricmin]

Re: battery charging question

oh yes, one other question, with my motor running and battery connected all my gauges work fine (tach, rpm etc), when I disconnect the battery with the motor running the gauges stop working. Is this normal that the gauges run off the battery alone or should the motor be able to run them by itself? Thanks<br /><br />Rick

 

[roscoe]

Re: battery charging question

Something is amiss with the charging system.<br /><br />Do not disconnect your battery from the running engine. It needs to stay connected to the battery.<br /><br />Also, if you are running a multiple battery setup, with a 1-2-both switch, do not turn the switch while the motor is running.

 

[Boatist]

Re: battery charging question

Ricmin<br />I know nothing about your engine but will tell you on many motors if you disconect the battery for even 1/4 of a second you will blow output diodes and voltage regulator. This also holds true for turning a battery switch with engine running unless it is a make second battery before break first battery. Even if make before break and you turn thru off it will damage output diodes or voltage regulator.

 

[ricmin]

Re: battery charging question

punt