(quoted from post at 12:48:44 08/05/22) Janicholson,
Nope not true. Old wife's tale! 1 wire generators-alternators do not discharge a battery. One wire simple setup! It just mean that the voltage regulator is inside the alternator.
Guido.
ou fellas don't measure twice & cut once, do you? If you did, you would know that both 3 wire and one wire alt has a continuous drain as long as battery is connected. It is small, but always draining.
Posted by JMOR on December 21, 2008 at 04:53:08 from (76.187.218.177):
For all those who have complained about their batteries draining after tractor sits un-used for a week or so, the content of Mr. J.A. Nicholson's post over on the Farmall board, may explain the problem. I have personally measured the 'standby' alternator drain on a 1-wire set-up. I have measured that 'standby' drain on several 3-wire set-ups.
Jim says, "The internal VR in some of the one wire systems draws about 200ma (if measured across an open battery terminal) others draw more like 500ma or more."
Whereas, my measurements for 3-wire show 0.75ma.
Best case then is 200/0.75=267X worse AND worst case is 500/0.75=667X worse drain.
Knowing that you can't extract every last amp-hour out of a battery, for sake of this discussion let us assume that we can. Real life results won't be this good, by some margin. Further more, if you did extract every last A-H, then there would be zero left to operate a starter.
Start with a 75amp-hour full charged battery. Apply the 3-wire 0.75ma drain.
75A-H divided by 0.75ma=100,000 hours. Divided by 24hr/day, yields 4,167 days (or 11 years). We all know that most batteries sitting on a shelf connected to nothing won't last that long. So what this says to me is that the 0.75ma drain is reasonably insignificant.
BUT, look what happens when we apply the 267X worse or the 667X worse 1-wire 'standby' drains: the 4,167 days divided by 267=15 days.***
Even worse, 4,167 divided by 667=6 days.*****
NOW, as I said in the beginning, I have not personally measured the 'standby' drain on a 1-wire set-up, but have no reason to doubt Mr. Nicholson. So, it seems reasonable then that a dead battery after a few days might very well be related to a 1-wire alternator.
Rather than speculation or even testimonials, such as 'mine doesn't discharge that fast', I would like to see a good hand full of 'standby' drain current measurements made & posted by anyone able to perform same.
No doubt, all 1-wire regulators are not born equal.
It could be that when & where those high 'standby' drains are encountered, that the regulator is just plain faulty and really has nothing to do with 1-wire vs 3-wire. However, speculation, testimonials are not the answer, just some real current measurements.
My one wire measurement show 2.5X the drain of 3-wire. Not as much as MR. Nicholson found, but never the less considerably higher than 3-wire.
I hope we see some measurements!
