[humfrz]

Originally Posted by notout86

I recently learned that, without modification, there is no possibility of ever FULLY charging the battery BY DRIVING.
Thus our batteries are not lasting as long as they might, especially if the charge gets low e.g. if allowed to stand for a few days.

This is probably because software control is aimed at reducing alternator load to produce better fuel economy figures in government testing.

In our cars, if the battery is low, on startup "it will deliver about 20A at 14.45V for a minute, then reduce to about 4A for a couple of minutes then taper off to NIL
with the voltage across the battery falling below 13V."

In prior decades the alternator would supply a constant 14.4V.
If anyone knows how to change our software to make that happen then let us know.

Meanwhile, using a charger regularly to top up the battery is a solution.

Well, I don't know about all of that, all I know is that the alternator in my 2013 FR-S produced enough electricity to run the car and has kept the battery charged for the past 5 years, with many short trips.





humfrz