Battery voltage
Thread Starter
Le Mans Master
Joined: May 2006
Posts: 5,747
Likes: 224
From: Hillsboro Oregon
Battery voltage
What is the lowest battery voltage that should show on the DIC at engine start up ? 
Mine often shows about 11.5 at startup then rises to 14 while running
Mine often shows about 11.5 at startup then rises to 14 while running
Safety Car
Joined: Jul 2004
Posts: 3,904
Likes: 29
From: Vancouver Washington
When you turn the switch on you are looking at the battery's voltage, then after you start the car you are looking at the alternator's voltage. Check and see what the battery voltage is after the car has been run for a while.
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
The real answer to your question is:
Use a digital Voltmeter and read the Voltage at the battery before stating and during cranking. Before starting you should read (at a minimum) 12 VDC. A NEW battery will read 12.6 VDC. A used and maintained battery will read 11.6 - 12.3 VDC
A bad battery will read less than 11.3 VDC
When you crank the C5 ,,,, if your voltage drops below 11 VDC You need a new battery!
Battery voltage is inversely proportional to current. When the starter is drawing MAX current, your battery should be able to maintain a a minimum 11 VDC. Much less than that and ,,,your going to see a lot of DTCs ! The memory functions will start to reset to factory resets.
What type of battery is It and how old is it??
BC
Use a digital Voltmeter and read the Voltage at the battery before stating and during cranking. Before starting you should read (at a minimum) 12 VDC. A NEW battery will read 12.6 VDC. A used and maintained battery will read 11.6 - 12.3 VDC
A bad battery will read less than 11.3 VDC
When you crank the C5 ,,,, if your voltage drops below 11 VDC You need a new battery!
Battery voltage is inversely proportional to current. When the starter is drawing MAX current, your battery should be able to maintain a a minimum 11 VDC. Much less than that and ,,,your going to see a lot of DTCs !
The memory functions will start to reset to factory resets. What type of battery is It and how old is it??
BC
Le Mans Master
Joined: Sep 2003
Posts: 8,847
Likes: 795
From: Longview Texas
The voltage on the DIC will show .4 to .5 volts less than if you measure it across the battery terminals.
Anything less than 12 volts and you may have an internal problem with the battery.
When the battery is charging, the voltage at the battery is also more than on the DIC.
I sometimes see 14.4-14.5 on the DIC with the car running. As the battery recovers, it comes down to around 13.9.
Anything less than 12 volts and you may have an internal problem with the battery.
When the battery is charging, the voltage at the battery is also more than on the DIC.
I sometimes see 14.4-14.5 on the DIC with the car running. As the battery recovers, it comes down to around 13.9.
