Quota over charging, regulator bad or something else?

[Perazzimx14]

Tends to melt in high tempretures.

In Germany Vaseline called Weinerslider

[Ariel]

Check your grounds.
The Regulator ground is the metal case.
If you measure resistance between the metal case of the Regulator to the (-) Battery connection, you should see short circuit, or very low resistance.
This is critical, otherwise you will have charging issues.

[Kiwi_Roy]

Sounds like an auto ranging voltmeter, and it is displaying 261 MILLI volts. As in .261 volts. As in about 1/4 volt.
Probably a pretty normal voltage drop.

It is an odd failure mode for that regular to internally fail in constant overcharge, but I think that is what you have.

This sounds right to me, if you look at the Voltage chart on my schematic Reply #3 you will see the regulator ceases conducting at 13.9 Volts (at the black wire), add the 0.261 Voltage drop between battery + makes it 14.16 Volts at the battery.
BUT, is this 0.261 constant? As I suggested a tiny resistance change in the relay contacts will throw it out. The headlight draws ~4.5 Amps
As I said in my PM the Normally closed Start relay contact is particularly weak.
You might want to pull the contacts out of the relay bases and tighten them up a bit, if you look at the base you will see a small opening where you can slide a sliver of metal 1mm wide to release the contact.
New relays are always a good idea, keep the old ones for projects like headlight relays.
 

[SPScottNT]

Hi,

I experienced something similar on a new to me SP III (Ducati charging system).  Initial symptom was new battery that went bad soon after installation.  Voltmeter readings were 15.5 volts at the battery when running, 11.5 volts at the reference wire into the VR.  After a back and forth with Kiwi Roy very similar to the above thread (if you sin, see the Pope; if you have electrical issues, see Kiwi Roy), I installed the following bodge (ahem...workaround):

VR Reference wire to standard automotive relay switch terminal 86, wire from terminal 85 to ground.  Wire from battery positive to fuse to relay terminal 30.  Wire from relay terminal 87 to VR reference input.  I used the original reference wire to operate a relay switch so now the VR sees actual battery voltage.  Now battery voltage at charging speed is 14.1.  Perhaps a bit low, but I am no longer frying batteries.

Its a bodge, and I am not sure why the original wiring causes the reference voltage to be 11.5 (and then cause overcharging) - perhaps the main key switch that everything seems to run through is making poor contact and causing a voltage drop. 

Scott

[Kiwi_Roy]

Scott,
4 Volts drop, that's what I'm talking about.
A good fix with a dedicated relay
If you want to increase the charge Voltage add a diode in series with the reference (black wire), that will add 0.6 Volts
If you look at my schematic there is already one inside the case.
Adding resistance to the black wire will also do it.

[SPScottNT]

Thanks Roy.  How are diodes specified and what rating of diode would give me a .6v increase.  Probably .3v or .4v increase (from my current 14.1v) would be ideal.

Scott

[Kiwi_Roy]

A typical silicone diode is 0.6 Volts in the forward direction large ones might be 0.5.
Any small diode from 1 Amp on up any Voltage rating.
Or you could try a 47 Ohm resistor in series and go up or down from there, I believe the reference draws about 12 milliamps but you can measure it and use Ohms Law to figure it out.
Current x Resistance = Voltage Gain
Hey, a 100 Ohm wire wound Potentiometer and you could set it where you like.

[Wayne Orwig]

Thanks Roy.  How are diodes specified and what rating of diode would give me a .6v increase.  Probably .3v or .4v increase (from my current 14.1v) would be ideal.

You could go with a schottky diode for about a .3 volt drop in the sense/reference line. A normal .6 volt silicone diode drop would get the battery voltage to 14.7 or so. Fine for short rides, Actually a good thing in a way. But hours of that will eventually cook a lead acid battery unless you constantly watch the water level in it. About any small diode will handle the tiny current.
Ideally, A silicone diode with a switch across it. And OF COURSE a voltmeter on the dash. On long trips flip the switch to short out the diode, to drop the voltage.
Me, I would run it at 14.1 and not worry. My EV battery lasted over 10 years at that charge voltage.

[usedtobefast]

Hi,

I experienced something similar on a new to me SP III (Ducati charging system).  Initial symptom was new battery that went bad soon after installation.  Voltmeter readings were 15.5 volts at the battery when running, 11.5 volts at the reference wire into the VR.  After a back and forth with Kiwi Roy very similar to the above thread (if you sin, see the Pope; if you have electrical issues, see Kiwi Roy), I installed the following bodge (ahem...workaround):

VR Reference wire to standard automotive relay switch terminal 86, wire from terminal 85 to ground.  Wire from battery positive to fuse to relay terminal 30.  Wire from relay terminal 87 to VR reference input.  I used the original reference wire to operate a relay switch so now the VR sees actual battery voltage.  Now battery voltage at charging speed is 14.1.  Perhaps a bit low, but I am no longer frying batteries.

Its a bodge, and I am not sure why the original wiring causes the reference voltage to be 11.5 (and then cause overcharging) - perhaps the main key switch that everything seems to run through is making poor contact and causing a voltage drop. 

Scott

This is great info.  Now, dumb questions ... do you get a one relay holder socket thing, wire it up, bolt it somewhere, and plug in a relay?  Or do you just connect all that wiring up to the 1 relay (flat blade crimp on connector style) and cable tie it in place somewhere with the wiring loom? 

[usedtobefast]

Ok, so I ordered a new Moto Guzzi Ducati Energia regulator from MGCycles.  That China knock off eBay one sure had a tempting price, but I don't really want to install a mystery piece into this puzzle.      I figure at this point my possibly original regulator has had a hard life. 

So new relays and regulator shipping out. 

When that all shows up I'll get the new bits on there and check numbers again.  Sounds like I might still be seeing a low reference voltage even with new bits.  But hey, I'll have 5 extra relays at that point!   

So if I have the same situation as SPScottNT, sounds like a new reference voltage source with a relay will then be kinder to the battery and regulator.  And if I end up there, I might just live with 14.1 vs. doing the tweak/adjust diode route ... but that does sound interesting. 

Then I drift off into silliness ... thinking ... yes, put in the switchable diode, that's cool ... but wait, if I have a voltmeter on board too, maybe once it see volts at a certain point then it switches the diode so the charging voltage goes up or down as needed ...  ahhhh, yes, build an external regulator from various bits and pieces to help the regulator.   

Thanks much kiwi_roy and others, this has been a great learning experience for me.  Looking forward to getting this dialed in. 

[Kiwi_Roy]

I use the relays without a holder, just get the appropriate size spade connectors, the alternative is to get one of those cube relays with a mounting tag.
Here is a topic on refurbishing the relay bases/
https://www.v11lemans.com/forums/index.php?/topic/20534-relay-base-repair/&tab=comments#comment-169917

[SPScottNT]

It's been a few years, but my recollection is that I used a cube relay with a mounting tab/bracket and found someplace to bolt it to the frame.  Its been charging fine at 14.1 so I have not been all that motivated to add a diode or resistor, but should I find myself with time on my hands that may be another easy modification.  Good luck getting it sorted.

Scott

[usedtobefast]

OK, update time.

Got the new regulator from MGCycles.  It came before the relays, so I swapped the regulator out first.

Tested the charging, around 13.4 at idle and around 14.1 at 4000 rpms .

Then the relays showed up, took old ones out, put new ones in, tested, exact same numbers.

I did not pull the reference voltage line going into the regulator and test that ... but I'm assuming it is still in the 11.6-11.8v and so the regulator just runs at it's max.

Not sure if that will hurt the life of the regulator, like running at 14.1 all the time, maybe all is fine.

So I guess I worried and thought about this too much!    Ain't charging right, buy a new regulator, install, and get on with life.   

Thanks to all the help, tips, info, hints, etc.

Pic of the bike out on it's essential test ride today:

[Wayne Orwig]

So I guess I worried and thought about this too much!    Ain't charging right, buy a new regulator, install, and get on with life.