> I probably shouldn't have said idle. Assuming that the alternator is making
> the electronics work better, you want output all the way from the lowest RPM
> that the engine is operated at during a race.
Ok, that I'll buy.
> My assumption is that even though the systems "work" they are
> probably not optimal until the cut off of their internal voltage regulator.
Very likely true, for a "points replacement" type ignition, as well as for
points. I suspect it makes less difference for something like a MSD 6.
> I suspect Gel Cells
> might have higher internal resistance than standard lead acid batteries and
> therefore exhibit a higher voltage drop under load.
Yes, they do, even for the same capacity battery. And since I'd guess you're
running a very small (compared to a standard car battery) gel cell, it's
internal resistance will be even higher.
> I can't find any documentation of this
Unfortunately, it's not a parameter that is normally documented, since it's
value also depends on the state of charge of the battery. As the battery
discharges, it's internal resistance goes up. Like so many other battery
parameters, internal resistance also depends on current draw.
> and I don't remember how to measure internal
> resistance--though I suspect I could figure it out if I wasn't so lazy. When
> it's discharged to the point that it won't reliably crank the starter the
> running voltage with the MSD 6AL was 10.2V. Ballpark similar conditions
> with BPC it's 11.7V.
So at that state of charge, the internal resistance is 1.5 divided by the
difference in current draw ... assuming your meter reads average rather than
peak.
> The MSD draws a healthy amount of current.
ISTR the sheet says up to 10 amps.
> I think it got permanently borrowed.
Wasn't me !! (darn it)
Randall
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