GTE,
I have only one battery for both house and engine, my alternator is rated at 120 amps, and I control the voltage it is told to seek and hold manually. Thanks again Mex.
I also have two ammeters, one shunted, and one with a hall effect sensor whose ring is on my (+) battery cable, the 500 amp deltec shunt is obviously on the ground. The rear ammeter has a voltmeter too, and my dashboard has two voltmeters, 3 wire ones with the third wire being for voltage sense. 2 voltmeters there as I use to have a 2 batteries, but now the engine battery voltmeter just taps into a nearby (+).
Now the refresh rates of these ammeters are likely 2 times a second for each, and the shunted meter, when I have looked at it during engine cranking was 128 amps, and my hall effect meter is rated for only 100 amps, and during cold starts will read ---, meaning it is over 100 amps.
Both of these ammeters read within 3 amps of each other upto that 100 amps and my clamp on ammeter also is within that range.
I too was surprised when the chock full healthy AGM battery's amps tapered back to 0.0 amps in 45 seconds or less. The ammeter starts up in the 70's, and within a 3 seconds in in the 40's and tapers quickly from there when I have set the voltage at 14.7v.
I was so in belief at this actual data, that I kept the battery full overnight on my Meanwell, and took video The next day, showing the battery accepting 0.0 amps at 14.7v, then stating the engine, and witching back and forth between dashboard and battery monitor in the rear.
The fact remains, and I could prove it, that the amps into the battery after startung the engine, tapered back to 0.0x in less than 45 seconds.
So instead of calling BS on actual data perhaps you should go collect data of your own, rather than relying on theory, as this is one of those times where perceived what should happen, is not happening in actual life. Makes me question most everything I read concerning the opinions by self described experts.
And as far as the voltage control of Newer vehicles, My elderly parents have 2014 or newer GM vehicles, and when I do drive them, I have the dashboard set to display the voltage. Crusiing ad accellerating the voltage is in the 12.7 to 12.8 range, take my foot off the gas and this shoots up into the 14's.
Again, actual observations.
Only one of those GM vehicles has the stop start, and the first few times drivving it, the stalling when stopped alarmed me, and I was asking my dad how do I turn of this freaking stupid asinine feature, but as quick as I could move my foot from brake to gas pedal the engine was already started and ready to accellerate. It can be turned off, My dad did so in thebeginning, but then said F it. and I also got used to it stalling when stopped, and it does not restart unnoticeably, and when the Aircon is on, it will restart when still stopped, which seems a bit pointless from a fuel savings scenario. I do not bother going through the process to turn off the stop start feature. perhaps if it were my vehicle and I planned on keeping it for 200K+ miles I would permanently disable it, but it is a lease.
