Battery voltage

[2010_camaro]

What voltage is normal for cruising?
I was seeing 14.5 for a few days but now it's at 12.5. I'm not having issues but that 2 volts makes a big difference with my fuel pump.

[Kopterman]

When the engine is running you will see ~14.5. With the key in the run position but the engine not running you will see ~12.5.

[Olddudesrule]

The voltage will change as the alternator works to maintain the batteries voltage level. If you don't have it connected to a BT when not in use, it will read (or should read) 14.5+ for a period of time as the car is started, as the battery gets recharged. Once there, the alternator will lower the charging voltage down to the 13's and then should rest at around 12.5+. It should not remain at any set number all the time, as it is continually compensating for the batteries current charge level.

You volt meter was at 14.5 while the battery was recharging, probably after a period of no or little use. It dropped to 12.5 after the battery reached optimal charge. You wouldn't want the alternator overcharging the battery while driving any more than you would want any other type of battery charger/maintainer overcharging it.

[2010_camaro]

Ya it sits at 12.5 -12.6 going down the road.

[frankwjr]

Brings up an interesting option available to car stereo tuners is to upgrade the cars system to either a 14 or even 16 volt system...not sure entirely on what exactly is required to make it work but you stated your pump likes 14...well here's an option...good luck..

[2010_camaro]

Need to figure out a way to get this at 14ish volts.
I'm running the Holley 12-1600 pump. Currently one pump is on all the time the second pump kicks in at 4lbs via a hobs switch.
I can tell a difference in the car when the alternator is at 14.5 volts compared to the 12.5 is at now.

[malibupaul]

My stock 2013 LS radio is going crazy. It runs between 15.1 and 15.2 volts. I ran the car for over an hour and this voltage was constant. I soon as I got home I checked the battery. It read 12.63 volts. I started it and it read 14.9 volts, but after 60 seconds or so, it went to 15.1, 15.2 again. The radio works fine in accessory mode. Also works fine with the engine running but the alternator disconnected. The dealer swapped out the alternator but that didn’t fix it. Is it overcharging and could the new alternator (voltage regulator) be bad?

[1JEWLDSSRS]

Originally Posted by 2010_camaro

What voltage is normal for cruising?
I was seeing 14.5 for a few days but now it's at 12.5. I'm not having issues but that 2 volts makes a big difference with my fuel pump.

See post #7...

https://www.camaro5.com/forums/showthread.php?t=245282

[malibupaul]

I saw that. It led me to believe that my car is overcharging. Except to say I didn’t understand the Commanded Duty Cycle 90% 15.5V. And it looked like a message doesn’t display until you get to 16V.

[Mouse330]

[QUOTE=2010_camaro;9695609]Need to figure out a way to get this at 14ish volts.
I'm running the Holley 12-1600 pump. Currently one pump is on all the time the second pump kicks in at 4lbs via a hobs switch.
I can tell a difference in the car when the alternator is at 14.5 volts compared to the 12.5 is at now.[/QU

Its a 12V pump its in your head....Unless u are getting any codes or messages.............

Its called The Electrical power management system, It performs 3 functions:

monitors the battery voltage and estimates the battery condition, takes corrective actions by boosting idle speeds, and adjusting the regulated voltage, performs diagnostics and driver notification.

There are also 6 modes of operation
Battery Sulfation Mode
Charge Mode
Fuel Economy Mode
Headlamp Mode
Start Up Mode
Voltage Reduction Mode.
The voltage can range from 12.5-15.5 volts. If you are not getting messages in the driver information center then the system is functioning properly.

[1JEWLDSSRS]

[QUOTE=Mouse330;11483878]

Originally Posted by 2010_camaro

Need to figure out a way to get this at 14ish volts.
I'm running the Holley 12-1600 pump. Currently one pump is on all the time the second pump kicks in at 4lbs via a hobs switch.
I can tell a difference in the car when the alternator is at 14.5 volts compared to the 12.5 is at now.[/QU

Its a 12V pump its in your head....Unless u are getting any codes or messages.............

Its called The Electrical power management system, It performs 3 functions:

monitors the battery voltage and estimates the battery condition, takes corrective actions by boosting idle speeds, and adjusting the regulated voltage, performs diagnostics and driver notification.

There are also 6 modes of operation
Battery Sulfation Mode
Charge Mode
Fuel Economy Mode
Headlamp Mode
Start Up Mode
Voltage Reduction Mode.
The voltage can range from 12.5-15.5 volts. If you are not getting messages in the driver information center then the system is functioning properly.

Great info Mouse...

[acammer]

[QUOTE=Mouse330;11483878]

Originally Posted by 2010_camaro

Need to figure out a way to get this at 14ish volts.
I'm running the Holley 12-1600 pump. Currently one pump is on all the time the second pump kicks in at 4lbs via a hobs switch.
I can tell a difference in the car when the alternator is at 14.5 volts compared to the 12.5 is at now.[/QU

Its a 12V pump its in your head....Unless u are getting any codes or messages.............

Its called The Electrical power management system, It performs 3 functions:

monitors the battery voltage and estimates the battery condition, takes corrective actions by boosting idle speeds, and adjusting the regulated voltage, performs diagnostics and driver notification.

There are also 6 modes of operation
Battery Sulfation Mode
Charge Mode
Fuel Economy Mode
Headlamp Mode
Start Up Mode
Voltage Reduction Mode.
The voltage can range from 12.5-15.5 volts. If you are not getting messages in the driver information center then the system is functioning properly.

This is good info for those that don't understand that the system is not a simple system regulated to a set voltage, but rather a complex control scheme that throttles the alternator based on a variety of factors.

Where I disagree is saying "It's a 12v pump, it's in your head". There is a fairly substantial difference in the flow/pressure a fuel pump can deliver over just a volt or two difference. In a fuel system that has ample headroom, this shouldn't be a huge concern, but on systems that are operating on the edge of a pumps capacity when it see's 14.5v, dipping to 12.5v is a real problem.

I'm actually working on a car that's encountering this right now - still experimenting with HPTuner's available tables to control alternator output. There are fuel demand tables, but it doesn't seem to respect those, so probably will try defining a minimum duty cycle next to see if that will get it to hold a steady 14+ volts.