Anyone monitor their battery voltage during daily driving? I have a voltmeter that plugs in to the cigarette lighter. When the car is not running, it reads 12.3-12.4 volts. While driving, it fluctuates between 12.5 and 14.2v. It will stay at around 12.5v at times then jump up to 14v for a while, and then back down. This is with lights and A/C off and driving at around 2000rpm. I thought it should always read at least high 13s when the car is running, no matter if accessories are on or not. If the A/C is turned on, it remains at 14.2v. I'm running red top optima battery thats about 6 months old. Is this normal? I'm going to try my original battery that I keep charged up and see if it does the same thing.

 

i use my radar detector to monitor mine (passport 8500) and while on th ehwy it pretty much stays around 13.8 when i let off the gas sometimes it dips into the 12.4-8 range. in the city it fluctuates. like that. i would say its normal

 

ya normal, my capacitor reads the voltage and I go from 12.5 - 14.5

 

Thanks!

 

my RSM reads from 13.2 to 14.7, so I'd say you are ok