Voltage Regulator
Thread Starter
Le Mans Master
Joined: May 2000
Posts: 8,729
Likes: 1,508
From: Redmond WA
Voltage Regulator
I understand how the old mechanical and the later solid state voltage regulators work, but I'm wondering if in the modern car the ECM has any input on when the alternator field is active (ie: when it's commanded to charge)?
I was thinking that (as long as the battery wasn't at risk of being overcharged) you could employ smart strategies like to go to MAX CHARGE on engine braking or even engine decel, and then cut the field on acceleration to increase power (or reduce it - the EFI and fuel pump have certain needs too).
Anyone know? Is it still an analog feedback circuit or does the ECM participate?
I was thinking that (as long as the battery wasn't at risk of being overcharged) you could employ smart strategies like to go to MAX CHARGE on engine braking or even engine decel, and then cut the field on acceleration to increase power (or reduce it - the EFI and fuel pump have certain needs too).
Anyone know? Is it still an analog feedback circuit or does the ECM participate?
Racer
Joined: Apr 2013
Posts: 305
Likes: 67
From: york south carolina
I use to do something like this many years ago. When u had mechanical points it did not affect power at all. But when i tried it on electrical distributor system ignition power was reduced do the drop in battery voltage 14 to 12 so i learned it was best left alone. But this was just me fyi
Drifting
Joined: Oct 2005
Posts: 1,354
Likes: 717
From: Terrell North Carolina
The ECM & BCM control all these days. The BCM &ECM all talk to each other & they determine what is needed where & when. If you have a C7 & you have the display up the gives you all the engine readings, watch the volt read out sometime. The computers check the battery all the time. You will see the voltage go up & down as the demand changes. Even smarter, watch your oil pressure sometime, it will amaze you how much it changes as demand & self testing the system makes changes to check itself out. If most realized how many computers are one the C7, you would think it is a miracle it all manages to work at all. At last count, there are 26 modules/ computers on the C7 & more to come on the C8.
Le Mans Master
Joined: Oct 2014
Posts: 8,673
Likes: 2,728
From: Atlanta GA
Belvin is correct , on older cars you would see a constant 14.1 to 14.5 charge no matter what the state of the battery charge . In a C7 , watch the volt meter , it will range anywhere from 12.8 to 15.0 depending on the state of the battery and what the draw is . The ECM eliminates the needless charging in an effort to not over charge the battery or waste HP / gasoline charging when it's not needed ...
Dave
Dave
