Re: Volt or amp gauge installation
Take a reading with a Digital Voltmetre with engine off.<br /><br />Start engine and take another reading.<br />If it is charging, the reading will be higher.<br /><br />Remember that the difference between Half Charge and full charge is around .5 volt so you need a digital Voltmetre.<br /><br />Usefull numbers:<br />Battery near full charge while charging 14.4v to 15.0v <br />Battery near full discharge while charging 12.3v to 13.2v <br />Battery fully charged with light load 12.4v to 12.7v <br />Battery fully charged with heavy load 11.5v to 12.5v <br />No charge or discharge for 6 hours - 100% charged 12.7v<br />No charge or discharge for 6 hours - 80% charged 12.5v<br />No charge or discharge for 6 hours - 60% charged 12.2v<br />No charge or discharge for 6 hours - 40% charged 11.9v <br />No charge or discharge for 6 hours - 20% charged 11.6v <br />No charge or discharge for 6 hours - Fully discharged 11.4v <br />Battery near full discharge while discharging 10.2v to 11.2v<br /><br />Battery voltage will vary for the same state-of-charge depending on whether the battery is being charged or discharged, and what the current flow is in relation to the size of the battery. The chart below will give you an idea of state-of-charge for various battery conditions in flooded cell lead-acid batteries. Voltage varies with temperature. While charging, a lower temperature will increase battery voltage. Voltage on a 12 volt battery is 0.9 volts higher at 32ºdegrees than 70ºF. While discharging, a higher temperature will increase battery voltage. There is little temperature effect while a battery is standing. (This information courtesy of Ralph Heisy, Bogart Engineering.)
