Alternator Ripple Voltage

[addo]

A couple of interesting morsels in the pasted comment (from a 2006 thread):

I wasn't too concerned about the low load charging voltage because many (cheap?) digital multimeters are prone to giving wrong readings when there is a high ripple content in the voltage being measured. As the alternator is loaded, the peaks of the ripple decrease and the apparent DC value falls.

Valeo regulators are set too high anyway, giving short lamp life and battery gassing on most French cars. I just live with it and change the lamps, but this can be a pain on vehicles with inaccessible panel lamps.

rotodiesel.

My 605 has an RE55 external reg fitted - no idea how this has been cobbled, but its dash lights flicker noticeably at lower engine speeds. It also seems to be mysteriously losing charge, slow to regain despite a healthy voltage reading and has no aftermarket gear fitted... Beautifully accessible, too. Not!

[Peter.N.]

If you have a good battery with solid connections you should hardly have any ripple as the battery acts as a large capacitor, you can check if the battery is overcharging by connecting an ammeter in circuit with the battery fully charged, shouldn't be passing more than an amp or two. Never heard of an extra regulator being fitted, must be something peculiar to 'down under' A heavy diode connected in series with the alternator will give a 0.6v drop.

Peter