Re: Installing a voltage guage
The battery is the heart of the boats electrical system. All power used by the boats accessories is drawn from the battery. The job of the engine alternator is to replenish the current drawn from the battery. When you turn the key on but have not started the engine, the voltmeter will read battery voltage. It should read about 12.6 volts. Since the gauge is not calibrated that closesly, as long as it reads about 12 volts that's an indication the battery is charged. When you start the engine and rev it to about 1500 or so, the voltage should increase to about 13.6 - 14.5 volts give or take a little. That is the indication the battery is being charged. A voltmeter cannot tell you the "condition" of the battery other than its voltage. A battery must be "load tested" to determine if it has any bad cells. Inability to hold a charge however is a good indication that the battery is headed for "battery heaven". Such a condition would manifest itself as a very slow turning starter even after the engine was run long enough to where you know the battery should be fully charged. If you turn the key on and the voltage is 10 volts is an indication that something in the boat is operating even though the key is off, but it can also be due to a bad cell in the battery. Another way to look at this is that if the gauge reads above 13V all is ok with the charging system but is no guarantee the battery "condition" is ok. It just means it is receiving a charge. Any reading less than 13 volts with the engine running indicates the charging system is not working.
