Alternator with higher output?

[dark_bike]

After sorting a number of electrical problems, mainly due to a dodgy regulator, I'm still stuck with a nagging problem. I use the bike a lot for commuting and these are fairly short runs, about 25-30 km, sometimes in dense traffic, and always with lights on. I find that in the cold season the bike won't start after a couple of days as the battery isnt recharged enough. So far I've overcome it with putting the bike on a charger but that's cumbersome: I've got to roll out a cable to the front garden, connect the bike, charge, then reverse the procedure.

In short, can't the problem be solved by an alternator that has a higher output? and would that require a different regulator?

 

I've had this problem with a guzzi before, a 1991 Targa 750 and there the alternator output was simply too low to cope with a lot of city driving with lights on. At least that's what I was told.

 

 

any suggestions?

[thumper]

That should be enough time to charge a good battery. Did you check the volts at the battery with the bike off,

warm idle and @ 5000 rpm? If I remember it needs to be 14.2V approx. at the 4-5000 rpm.

[dark_bike]

That should be enough time to charge a good battery. Did you check the volts at the battery with the bike off,

warm idle and @ 5000 rpm? If I remember it needs to be 14.2V approx. at the 4-5000 rpm.

 

All fine, battery is a new hawker Odyssey, replaced battery and regulator about 3 months ago, cleaned any ground connections.

[Kiwi_Roy]

I'm with Thumper, the alternator is more than up to maintaining the battery if you have just the standard headlight etc. However it will loose ground when idling in traffic.

There are two reasons I know for weak charging.

An open circuit in one of the regulators diodes, this can be easily checked.

Bad ground on the regulator. I have seen this on several bikes, including my own, the tiny ground wire the factory provides is next to useless. The current pulses the regulator puts out are in excess of 30 Amps so you need something like #14 or 1mm at least. The connection between case and the chassis through the mounting bolts is ok until corrosion takes place which is inevitable with disimilar metals in a wet environment.

If you haven't already done so run a heavy wire between the regulator case and a handy engine bolt.

 

Charging Circuit Problems.pdf

Regulator Diode Tests.pdf

Shows some readings I took on a healthy bike.

Charging Circuit Tests.pdf

 

 

Roy

[dark_bike]

an update after much help from Kiwi_Roy.

 

I've fitted a headlight relay harness and it turns out that this puts the regulator on the wrong foot. When I've understood it correctly the regulator does not notice the voltage drop when the lights are switched on as the original wiring is bypassed, and hence cant compensate for that.

 

Tom

[gstallons]

For what it's worth; I use shakeproof (star) washers on ALL electrical ground connections..

[dark_bike]

Problem solved. On Roy's advice I've fitted a diode in rhe reference wire of the regulator and now the voltage is 14.4 instead of 13.8.

 

I,ve put the diode in aweatherproof fuseholder, and fitted that betwen the connectors of the reference wire.This can be easily done by pulling the connector apart and then join it up again so only the white wire is connected, and then I fitted the fuseholder between the connectors of the black wire.

 

the moral of the story is that if you fit a relay harness for the headlight to bypass thecstandard system, you also need to fit a diode to the reference wire in order to keep the charging voltage adequate.

 

tom

[Kiwi_Roy]

Tom,

I appreciate you had the confidence to try something untested. I'm glad it worked out for you.

 

With some back and forth Tom & I figured out that with standard wiring the regulator sees the battery Voltage minus the Voltage drop in the headlight circuit.

With headlight relays added this Voltage drop is lost because the headlight current no longer flows that way.

The regulator is set to 13.8 so the battery wasn't getting fully charged.

What Tom did is add a forward biased diode in the black reference wire, this fooled the regulator into thinking the battery was half a Volt lower

so it boosted the regulator output by 1/2 Volt to compensate.

 

A word of caution, don't just add a diode as Tom did without first of all trying the other causes of low voltage e.g. bad grounding

 

Roy

[docc]

And, so, those clever of us who have wired directly the headlamp, horns, GPS, and accessory plug (for heated jacket or such), will not be showing the reference wire this draw?

 

Good to know and unsettling at the same time . . .

 

So what diode for the headlamp correction? And then the GPS, too? And another for the accessory circuit?

 

Really, I thought the regulator would read actual voltage and charge accordingly. NO?

[Kiwi_Roy]

And, so, those clever of us who have wired directly the headlamp, horns, GPS, and accessory plug (for heated jacket or such), will not be showing the reference wire this draw?

 

Good to know and unsettling at the same time . . .

 

So what diode for the headlamp correction? And then the GPS, too? And another for the accessory circuit?

 

Really, I thought the regulator would read actual voltage and charge accordingly. NO?

Docc

Yes, as wired with the headlight drawing amps through the headlight relay the Voltage drop between battery and regulator added to 13.8, the regulator setpoint ensures that the

battery gets charged to over 14 Volts

However once you bypass the headlight current around the headlight relay you now get no Voltage drop so the regulator charges to 13.8 the point where the regulator cuts off.

My guess is Guzzi have the regulators made allowing for the voltage drop, then again they do try and put 45+ amps through the ignition switch powered by a 15 Amp fuse to pull

in the starter and they don't provide proper grounding for the Ducati regulator so perhaps they are lacking a little in electrical understanding.

 

When I get a bit more time I will take some careful measurements to back this up.

 

That's my

 

Roy

[docc]

This is likely the most break through development in spine frame wiring since we started bypassing the switches and adding bigger wires.

 

Who knew we were also bypassing the regulator reference?

 

No doubt, if these AGM batteries don't get more than 14v, they get unhappy . . .

[madridpunch]

This is likely the most break through development in spine frame wiring since we started bypassing the switches and adding bigger wires.

 

Who knew we were also bypassing the regulator reference?

 

No doubt, if these AGM batteries don't get more than 14v, they get unhappy . . .

 

In the sailing boat world there are aftermarket regulators available that directly sense the battery voltage (rather than the output voltage) and so keep the voltage higher for longer. Is there not an equivalent bike version (a boat one would be a bit big to hide on a bike...)

D

[dark_bike]

And, so, those clever of us who have wired directly the headlamp, horns, GPS, and accessory plug (for heated jacket or such), will not be showing the reference wire this draw?

 

Good to know and unsettling at the same time . . .

 

So what diode for the headlamp correction? And then the GPS, too? And another for the accessory circuit?

 

Really, I thought the regulator would read actual voltage and charge accordingly. NO?

 

I used a N4001 1amp silicon diode (cost €0.07). Of course you can solder it to a wire, tape it up and fit it but the fuse holder seemed a little more robust. The diode is in the reference wire, so that should cover all ancillaries you may have fitted that are wired directly from the battery.

Not sure what happens once the headlight is off, didnt check that. I guess the diode will increase the charging voltage by 0.6 V at all times, so the battery will reload even quicker then. to me it is pretty theoretical as these days it is obligatory to drive with dipped beam t all times, so the headlight is always on.

When you have loads of ancillaries running at the same time, but still have the original headlight wiring, fitting the diode may help to quickly reload the battery...or am I talking drivel here?

[dark_bike]

Tom,

I appreciate you had the confidence to try something untested. I'm glad it worked out for you.

 

With some back and forth Tom & I figured out that with standard wiring the regulator sees the battery Voltage minus the Voltage drop in the headlight circuit.

With headlight relays added this Voltage drop is lost because the headlight current no longer flows that way.

The regulator is set to 13.8 so the battery wasn't getting fully charged.

What Tom did is add a forward biased diode in the black reference wire, this fooled the regulator into thinking the battery was half a Volt lower

so it boosted the regulator output by 1/2 Volt to compensate.

 

A word of caution, don't just add a diode as Tom did without first of all trying the other causes of low voltage e.g. bad grounding

 

Roy

 

It's early days yet as I wont be using the bike for however long it's going to take for temperatures to get above 0 C again, but so far nothing melted or caught fire :-) . will keep you posted.

[Kiwi_Roy]

In the sailing boat world there are aftermarket regulators available that directly sense the battery voltage (rather than the output voltage) and so keep the voltage higher for longer. Is there not an equivalent bike version (a boat one would be a bit big to hide on a bike...)

D

http://www.thisoldtractor.com/guzzi007/schematics/2008_V7_Classic.gif

The later regulators (with the diode symbol) like on the V7 Classic are wired directly to the battery, they also include proper ground wires thus eliminating the bad connection there. The V11 sport (mine anyway) had the regulator screwed to the horn bracket with a couple of sheet metal type clip fasteners. The horn bracket is bolted to the frame with no sign of attention to grounding like bare metal to metal. The only sign of a ground is a tiny black wire, about 20 gauge under one of the regulator fasteners. I suspect when the bike is new the Aluminium to steel contact is sufficient but as the bike ages and corrosion takes place the direct contact to chassis is lost and it has to rely more on the tiny black wire. As a boater I think you will agree Aluminium to steel in a wet sometimes salty environment doesn't make for a good connection.

I drilled one of the regulator fins and ran a short #12 to a timing cover bolt. All of the charging current which peaks at well over 30 Amps has to pass back through the ground to regulator in order to complete the circuit to alternator.

 

I pulled my loom apart looking for the reference, it's taken off a Red/Black wire that runs from headlight relay to the headlight bucket. Midway under the tank is a soldered joint inside the loom.

 

The diode fix Tom did is one way to boost the Voltage a little, there are other ways.

The regulator has a trim resistor that's quite easily accessed but requires digging out some of the epoxy.

Instead of a diode a variable resistor in series with the reference would give full control.

The most important improvement to make before anything else is proper grounding, followed by checking the regulator diodes.