Charging Voltage

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  • Alright so how many can read the voltage while driving? I installed a Rockford Fosgate radio this winter and I am noticing that when driving it is reading a steady 13.2-13.3 volts. Is this correct? Coming from the car world I like to see 14.2-14.4 volts while running any help is greatly appreciated. I know the ECU has been flashed so I'm not sure if that has anything to do with it.

    Just a small town farmboy, handy with my hands and originally trained as a automotive technician. Lives in Swayzee Indiana.

  • Since I installed digital voltmeter, the typical voltage it shows is 13.2-13.3v, although my 4+ yr old battery sometimes drops as low as around 10.6V when starting the engine and if I hit my horn button it typically drops around .1V from its normal voltage. I assume I'll finally need to swap out my battery soon.

  • Technically anything over 12 should be good....my 4 wheel vehicles are around 14 ish....the SS as mentioned around 13.3 - 13.4


    The age of the battery doesn’t have anything to do with charging voltage....that’s what’s coming out of the gen/alt...


    If your battery won’t stay charged with 13 ish you need a new battery or you have something draining it with the key off...



    Or you’re really pulling some amperage with lights or other stuff....and the gen/alt can’t keep up to the draw.

  • Alright so how many can read the voltage while driving? I installed a Rockford Fosgate radio this winter and I am noticing that when driving it is reading a steady 13.2-13.3 volts. Is this correct? Coming from the car world I like to see 14.2-14.4 volts while running any help is greatly appreciated. I know the ECU has been flashed so I'm not sure if that has anything to do with it.

    ......before I did the upgrade of my alternator to 240 amps (w/cables & yellow top Optima battery) I had the same readings on my volt gauge but after, I now get 14.2-14.4.......I believe the OEM alternator is only 140 amps.....

  • I'm thinking it it alternator controlled. I might need to see if i can call someone that rebuilds them to tell me. I would like 14.4V as that is "normal" to me. I haven't had an issue with the battery yet, I left it on a trickle charger over winter.

    Just a small town farmboy, handy with my hands and originally trained as a automotive technician. Lives in Swayzee Indiana.

  • I'm thinking it it alternator controlled

    .


    Charging voltage for the stock alternator is controlled through the ECU directly. If it only needs 13.2 it only produces 13.2 for less parasitic drag ..... aftermarket higher output alternators use an internal voltage regulator ... that's why many produce a permanent CEL .....


    .... nerd-squared


    .

    :REDSS: The ghost of SLingshot past ......

  • I have a 2018 SL only electrical add-ons are air horn and modulated 3rd brake light my digital volt meter reads 12.9 while driving.

    Can you disconnect each one separately to see which one is drawing the most? Then do both and see what it reads.

    You could take it to advance or autozone to have them check the alternator just to see how much they get.