[COLVERT]

Originally Posted by RPWC

My brother in law called me today to ask about a battery problem. I popped round with a voltmeter after he had charged the battery and taken the car for a good run. The reading was 12.83, after starting the engine it went to 13.88, but when the revs were increased the reading remained static, instead of inreasing to 14.3. Does this mean the alternator is not charging?. I tested my own vehicle and once the engine was started and revs increased it went sraight to 14.3v.

Interesting that he found the need to go for a good run.--


The lower voltage could indicate the battery was nearly fully charged. The internal resistance of the battery INCREASES as it charges. Could be making that multi-meter voltage drop slightly.

Also the voltage regulator could be the limiting factor due to a slight change in which its internal components are working.

However 13..88 volts will keep the battery charged in normal use of the car.---

Don't forget that you will only get an accurate voltage reading from the battery several hours after it has come off charge. Immediate readings are never accurate.---