one wire alt parasitic drains re-visited

JMOR

Well-known Member
Location
TX
Mr. Nicholson, I know this is a month old post, but I have been researching one-wire 10SI VRs and it makes me question the heavy 50 mA drain that you quoted. If it was the typical one-wire, there is zero battery connection to its 5 terminals (3 bolted plus the 2 spade connections), so I see no way such VR could ever have a parasitic drain. The typical one-wire unit should have an even smaller drain than the 750 microamps of a real Delco 3- wire! If a drain is measured on such alternator, I suggest there are only 3 possibilities, leakage thru faulty noise suppression capacitor, reverse leakage of rectifier bridge diodes, bad insulation, but not the VR. What say you?
 
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Mr. Nicholson, I know this is a month old post, but I have been researching one-wire 10SI VRs and it makes me question the heavy 50 mA drain that you quoted. If it was the typical one-wire, there is zero battery connection to its 5 terminals (3 bolted plus the 2 spade connections), so I see no way such VR could ever have a parasitic drain. The typical one-wire unit should have an even smaller drain than the 750 microamps of a real Delco 3- wire! If a drain is measured on such alternator, I suggest there are only 3 possibilities, leakage thru faulty noise suppression capacitor, reverse leakage of rectifier bridge diodes, bad insulation, but not the VR. What say you?
Jessie
I read in my Kubota manual that the Kubota battery will discharge at a half % per day.
I don't drive my truck very often. The battery is 3 years old. The parasitic drain is only 50 ma
It seems my truck battery self discharges at about a half % per day. I have to keep a charger on the truck.
I'm thinking we might be confusing parasitic drain with battery self discharge.
I think the only way to tell the difference between parasitic and self discharge would be for me to disconnect one wire and see if the battery self discharges.
 
Jessie
I read in my Kubota manual that the Kubota battery will discharge at a half % per day.
I don't drive my truck very often. The battery is 3 years old. The parasitic drain is only 50 ma
It seems my truck battery self discharges at about a half % per day. I have to keep a charger on the truck.
I'm thinking we might be confusing parasitic drain with battery self discharge.
I think the only way to tell the difference between parasitic and self discharge would be for me to disconnect one wire and see if the battery self discharges.
Just stick an ammeter in circuit. How else would Mr. Nicholson come up with 50mA and I can guarantee that an ammeter is how I have measured 750 microamperes on old original Delco 10SI regulator.
 
Just stick an ammeter in circuit. How else would Mr. Nicholson come up with 50mA and I can guarantee that an ammeter is how I have measured 750 microamperes on old original Delco 10SI regulator.
JMOR: There are several companies making one wire alternators including conversions of several OEM brands to one wire. there is are also technological changes that can allow less and less current flow while still allowing self-excitation. Rotation speed for self excitation is also changing for some one wire devices. I have installed early versions of one wire systems that draw down to non starting, a fully charged battery in a month or less. SO the end game is caution about assumptions both my estimate of potential current, and motivation to caution users. All good to me.
 
OK, but with the typical one-wire, such "leakage" is impossible, since there is NO battery connection to the VR (see one wire implementation diagram). Now if some way Battery gets connected, as maybe a 6th terminal, I'm all open for a draw down leakage, otherwise it just isn't going to happen. Perhaps show me a path....I am also open to learning.
 
I will choose to state that there has been one wire systems (and are probably still on the shelves) that internally connect to the Bat post. Not really important any more. I hope this closes this issue at this level. Jim
 
I will choose to state that there has been one wire systems (and are probably still on the shelves) that internally connect to the Bat post. Not really important any more. I hope this closes this issue at this level. Jim
Not closed, because, without a 6th terminal on the VR, to feed it battery voltage, there is no way for it to "internally connect to the battery post". V batt is not in the VR for it to be connected to. See blue outline boundaries of the VR........no V batt lines cross this boundary. Maybe others will come along with additional facts, but I don't expect the one-wire makers are real open with their designs. I have learned some of what I know by opening up a few of them. I don't even think they are regulating off of battery voltage, but rather, something close, such as reg off diode trio output, ...close by no cuppie doll. Just think about it.....Vbatt on a 3 wire got into the VR via spade#2, but with no #2 connection, that sure is not the 3 wire path.
 
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Come on fellas, it is really a reach to compare diode reverse leakage of 0.1 micro amperes (maybe a crappy diode at 30 micro amperes) to the quoted by some of 50 milliamperes parasitic drain of the alternators! The ratio is in the range of 1,000 to 10,000 to 1. Wrong tree! You will also note that the diode trio is only reverse biased on a 3 wire, when the ign sw is on and engine not running and never in the one wire that my discussion references. Somebody actually refute my position by taking the circuit diagram and drawing the path by which this typical one wire has a parasitic drain. Please.
 
Come on fellas, it is really a reach to compare diode reverse leakage of 0.1 micro amperes (maybe a crappy diode at 30 micro amperes) to the quoted by some of 50 milliamperes parasitic drain of the alternators! The ratio is in the range of 1,000 to 10,000 to 1. Wrong tree! You will also note that the diode trio is only reverse biased on a 3 wire, when the ign sw is on and engine not running and never in the one wire that my discussion references. Somebody actually refute my position by taking the circuit diagram and drawing the path by which this typical one wire has a parasitic drain. Please.
No offense, I respect you JMOR, and appreciate your wisdom. I am just not responding to this thread any more. Jim
 
No offense, I respect you JMOR, and appreciate your wisdom. I am just not responding to this thread any more. Jim
That is fine. The respect is mutual. I didn’t intend an attack on you. Your old thread just gave me an opening to get the 1wire drain out here again. I’m just trying to figure out the details and learn some things here, myself. Please accept my apologies where ever i may have caused harm.
As soon as I get it together I will post another 1wire that I think is not as “typical”. I have measured it at 1.8mA, as it IS always connected to the battery. It is claimed to kick in at lower rpm and I can see how that is possible. Also can see how it can sense battery voltage. I have this one running on my MF275.
 
I have two of the 12V kit 1-wires from this site, one on my 8N and the other on the 850. Both excite at fairly low RPM and charge well. About a week ago I checked the 8N, hadn't been started in at least 3 months, spun fast and lit right off, so I guess it wasn't drained much
 
Just stick an ammeter in circuit. How else would Mr. Nicholson come up with 50mA and I can guarantee that an ammeter is how I have measured 750 microamperes on old original Delco 10SI regulator.
Jessie my 3 wire declo generators used on my Jubilee and Farmall also have a 50 ma drain.
I fixed that problem by sending the two wires through the ignition switch. Switch off disconnects the 2 wires. Zero drain.
 
Jessie my 3 wire declo generators used on my Jubilee and Farmall also have a 50 ma drain.
I fixed that problem by sending the two wires through the ignition switch. Switch off disconnects the 2 wires. Zero drain.
I have a real problem with 50mA. That is 12v and 240 Ohm load! Probably kill battery in a month. I have measure several and never any that high. Even a modern vehicle with all the computers, etc. are less that 50mA.
 

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