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I intend to do a few more tests with the motor running and am also thinking of fitting a voltmeter so I can monitor whats happening as I ride. Have to keep it simple as I never did understand the Ducati electrics in the headlamp. Happily the charge system does not go there at all.

For what it's worth, I have recently purchased LED bulbs for the tail light, ignition and 'town' lights on my 175TS from this company https://www.classiccarleds.co.uk and they work fine.

They're cheap and the speed of delivery fantastic. They were literally plug in and play using my 6v electrics as well as being a hell of a lot brighter and less prome to vibration failure.

They do 6v and 12v and some in both positive and negative earth (don't ask me what positive earth is, that makes no sense to my tiny brain!).

Hope this may be of interest.

Jason.

I'm just throwing this out here for consideration.

Ducwiz is correct. A 60-watt alternator is a 60watt alternator. It can't supply any more. Wattage = volts x amps, so a 6-volt 60-watt alternator can supply 10 amps (6 volts x 10 amps = 60 watts). If you convert the 6-volts alternator to 12-volts, it's still a 60-watt alternator. So the amperage the 60-watt alternator can deliver is only 5 amps (12 volts x 5 amps = 60 watts).

Immediately I see a problem with the headlight in the conversion scenario. The 6-volt bikes usually run a 25 watt headlight. That leaves 60 minus 25 which is 35 watts left over for the taillight/brake light and ignition. 12-volt headlights are usually at a minimum 55-watts. That leaves 60 minus 55 watts which is just 5 watts left over for the ignition and taillight/brake light. The power needed to run anything more than the 60 watts the alternator puts out is going to come out of the battery, eventually draining it.

The use of an 12-volt LED headlight will help greatly to mitigate the power consumption of the headlight. Likewise an LED brake light will also save power. Maybe then your 12-volt 5-amp 60-watt alternator might be able to run all the electrical loads (lights and ignition system) and have a little left over to put some charge into the battery.

On the subject of voltmeters, I lost compression on my 250 that has a 60-watt alternator a couple years back and I have not gotten around to fixing it yet. But... Rather than put a voltmeter on the battery I was going to put an ammeter on the battery (that probably would require a shunt but that's too much to get into right now).

The ammeter was going to tell when and how much amperage I was putting into the battery at any given RPM or how much amperage I was pulling out of the battery at any given RPM. I as going to switch the headlight on and off to help better understand when I was charging and when I was draining the battery and how much amperage was flowing so I could understand the severity of the battery drain when it was occuring. Only knowing the voltage on the battery in my opinion doesn't give me the information I am seeking.

Positive earth is a mostly seen on vintage British bikes, they simply connected the positive terminal of the battery to the frame and fed wires from the negative battery terminal to the electrical devices.

Jim

Hi Jim, the bike has been no trouble electrically for 10 years since I did the 12v mods,including 4 ten day riding holidays in the IOM when I usually rode with daytime lights for safety. This last year though I ran with the lights off and kept the revs up to just keep going. Something has changed ,worst cenario is the rotor has come loose on the crank!, hope not.Maybee the magnetism is suffering from age,I know what that feels like.

Thank you Jim for your precise and extensive explanation. But - 55W of power consumption is only valid for H4 bulbs. Standard Tungsten wire bulbs are rated 40/45 W, at least in Europe. This makes the situation a bit more relaxed, but a leftover of 20 W anyhow, for the rear light and the other remaining loads is still not enough for a reliable charging of the battery.

cheers Hans

I am currently (!!) running a special 35/40 watt halogen bulb from Norbsa (Goffy) in a 130 mm headlamp that's really meant for tungsten bulbs plus an electronic points assist unit from Pazon so I am pushing the limits. probably a good idea to put in a low consumption Bright LED pilot and tail and stick to daylight running. Reading "BOBs" blurb its clear he thinks my existing charging arrangement is not getting the best output. Can't work out what he would change.

Hi All, Back with the 250 nc Mark3, Been away from Ducati's for a few years , got sidelined with Honda and Norton. Dragged the 250 out today ,blew off the dust of years and with a charged battery and the old fuel it started up 3rd kick. Next need to check that the bike is charging when running ,Not worried about lights at present,just want to get out for a 50 mile ride. Would normally expect a battery to last that long ,but this is not a new battery and the voltage was down to 12v after a minuits running .I intend to check the voltage at tickover and then at 3000 rpm. If I see an increase that will do for me at present. What do you think?.

Hi Bob
I have two originally 6V bikes running at 12V at the moment. The yellow wires from the alternator are connected to a generic R-R. The red wire from the alternator is not connected.
I fitted one of these to each bike to monitor the charging;
http://www.sparkbright.co.uk/sparkright ... onitor.php
At lower rpm, say less than about 2k or so, the battery doesn't charge, but over that the battery charges fine, even with the lights on.
I too have used Goffy's halogen lights.
Haven't run out of volts yet, I'm glad to say.
If you have a voltmeter to measure the battery, then normal charging voltage is about 14.4V.
Good luck!

Thanks Max, Last time I rode the little beast I was more than happy to get home and get off !. Not the most relaxing bike to ride, The motor kept wanting to stop, Fuel level too low ,an easy fix with the remote float SSI. Its also started to kick back, A sure sign that the points have closed up a bit. Thought I would dribble some oil into the bore before starting, mistake, now too much compression to kick over without breaking something ,bike or me.Psyching myself up to take it out tomorrow.