Just past break in, just broke?

Hey everyone,
Just passed my break in (1600km factory break in) on my 17 Gt PP on my way to work this morning and noticed my voltage was low (12.5-12.8V) compared to the other (pre 1600kms) day which was always around 14.2V. On start up after work, voltage was 14.1V but shortly after leaving the parking lot voltage dropped to around 12.6V. I can get the voltage back to 14.2v SOMETIMES if I bring rpms up past 4500 but not every time, and some times at low speed/rpm it will bounce between 12.6 to 14.9v.... Checked with my Fluke meter and it read 12.6v..... Should I be calling the dealer?? I read that the charging system will only produce the necessary voltage to run what is needed. Suggestions?

My GT/PP runs anywhere from 12.5V to 14.2V. 22k miles, and no problems with the charging system.

JR

These cars are equipped with a Smart charging system. Only charges battery when necessary. Normal operation.

Smart charging. It stops charging when the battery is full to reduce draw on the engine as well as prolong the battery life.

Thanks for the fast replies and info :-) kinda upset that there's nothing wrong cuz now I have to hear the "I told you so" from the wife lol thanks again for all the help. Great site, great cars, great people.

Just tell her it needs a supercharger to work right...

Haha she knows it doesn't need a blower to run, but she does know I'm getting one next spring I'm pretty sure she likes the car more then me so she's on board with anything lol happy wife happy life

My battery was garbage after 10 months. They replaced under warranty. Been a month amd a half and this one might be showing symptoms as well. 11.2 volts with just the ignition on.

Car is a daily with almost 3 years and 30,000 miles ownership. Battery is still in good shape!

I wouldn't be worried. Tell-tale warning lights "Batt" or idiot lights as some call them are used in most cars. They ease the mind of the majority of people that don't understand how the charging circuit works on a vehicle. You either have a problem, light ON, or you don't. They wouldn't know if slightly low or high voltage would be normal so a gauge isn't necessary.
The normal at rest fully charged battery would be 12.7 volts. The voltage regulator tries to keep the battery at this voltage by controlling the alternators output. The regulators controlling voltage ranges somewhere between 13.8 - 14.6 volts. Therefore as the battery is discharged by starting, running voltage and accessory use the regulator allows the alternator to supply whatever current is required to maintain the battery at optimum voltage.

Ominous1, you're charging system by your description seems to be working fine.
Kong76, turning the ignition ON and reading voltage only shows the batteries present state of charge. It's constantly discharging when not running as it has to supply current to run the PCM's Keep Alive Memory and any other modules that operate when vehicles not running ex. security system.
Now if your voltage was reading 10 - 11 volts as an example while driving, I would consider your charging system to be malfunctioning.

I'm a heavy duty mechanic by trade and I understand how charging systems work a long with dummy lights. I agree that most people don't want/care to know if they system is high/low, as long as it starts and runs. I like monitoring all vitals of the car just for personal knowledge of my vehicle. The new charging systems are slightly more advanced then I'm used to apparently. Voltage has never dropped below 12.6Vs so until it drops more then that, I'll leave it alone.

Good to here from someone else in the trades. I'm a recently retired truck/transport mechanic. I'm trying to talk myself into selling my S197 and buying a S550.

I'm loving mine so far, even comin from a 600whp F250