Battery Tester's Mysterious Fluctuations Unveiling Causes While Driving

On the way home on a 150 mile drive we noticed the volt meter fluctuate between 12 and 14 volts (I had a fluke meter with me). It was warm ... Get the battery load tested. Only way to confirm battery is indeed good and not having a weak cell only holding a ''surface'' charge. After 10 minutes or so of driving, the voltage of the battery will drop and hover in the range of 12.2-12.5. There are 2 ways is raises back up. yes perfectly normal. The ELD controls/adjusts the amperage outputted by your alternator depending on the load seen by the ELD. Apr 6, 2017 | 05 ... I measured this voltage using a battery analyzer which shows live output as well as with a fluke meter. Additionally I pulled the live data with ... Hello, does your battery gauge fluctuate while driving? I do not know what normal operation looks like on the battery meter. I am thinking ... This is completely normal with modern charging systems from GM and other manufacturers. Output voltage is computer controlled to provide only what is necessary ... one more to check if the current is to high for the battery there is a lot off gassing. All the gass bubles are dropping the charge current. I installed a AGM battery and with a volt meter I am reading 14.9-15.3 volts at the battery with it running in park. The needle on the dash ... I don't drive it that often. Maybe it's normal and something to do with recharging the battery after extended idle periods. Has anyone else ...