Charging issue with 58 Huntmaster

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Nickfrank
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Charging issue with 58 Huntmaster

Postby Nickfrank » Mon Sep 14, 2020 5:14 pm

I've posted to the Forum before on this but am still stymied trying to resolve the issue. When running, the bike discharges the battery fairly rapidly with the lights on - within a 20-30km ride I end up with a dim (or no) headlight, no horn, no tail light or brake light. The ammeter needle fluctuates a lot, mostly to negative. Once home within an hour the battery has recovered and everything is back to normal albeit with somewhat less than optimum voltage of course.
The dynamo has been removed, examined and checked out professionally. All is good.
It has a new 14amp/hr battery (the specs call for at least a 12amp/hr)
It has a new electronic voltage regulator from Draganfly (note the charging issue was occurring with the old voltage regulator)

I connected a multimeter between the charging system and the battery which was slightly discharged (5.9V) so I could see whether the dynamo would charge up the battery. I started the bike and immediately the multimeter was flashing random numbers. No way I could get a reading of any sort. My plan had been to study the voltage at idle, with increased revs and then when the lights were switched on.

Any advice from anyone who has had a problem like this would be much appreciated. Thanks.
Nick

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Re: Charging issue with 58 Huntmaster

Postby Pete.Silson » Mon Sep 14, 2020 7:22 pm

Nick,

Digital multimeters are not very good at measuring dynamo voltage because of all the electrical noise they generate. You might get a more usable reading using an old fashioned analogue moving-coil meter.

Pete

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Re: Charging issue with 58 Huntmaster

Postby will_curry » Mon Sep 14, 2020 7:49 pm

With the original mechanical regulator fitted a good dynamo should be able to
light the headlight with no trouble without the battery being connected.

DON'T try that with the electronic regulator fitted - it won't like it at all.

I've encountered odd problems with charging systems when the dynamo body has
been beautifully painted and so electrically insulated from earth. Try taking the cover off
and use a battery jump lead to connect an unpainted it of dynamo body to the battery earth.

Just occasionally a dynamo needs a bit of a jolt to start it. Flash from the battery live terminal
to the F and D terminals on the dynamo if nothing happens above.

When all is working your ammeter should show a steady 4 to 5 amp charge on first startup
and just a bit more than tickover. Once the regulator cuts in as the revs go up the needle
will start to flicker.

HTH

Will.

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Re: Charging issue with 58 Huntmaster

Postby keith.mettam » Mon Sep 14, 2020 8:07 pm

Hi Nick,
If I was you I would start with looking at the dynamo again and checking that. I use a digital multi-meter and have no issues at all with my meter when checking my charging system so don't worry too much about your meter just yet. Attached is a Lucas document which should help you with a voltage test on the dynamo in situ. There is also information on re-polarising the dynamo. If you take the dynamo off the bike you can 'motor' test it. It is easier to do this on a bench so I also remove the battery to use for this test. Both 'F' and 'D' terminals are connected together with a short piece of wire and a lead is run from them to the negative terminal of a charged battery (if positive earth). The body of the dynamo is then held on the positive battery terminal and the armature should spin in the same direction as the dynamo runs when fitted to the engine. If system is negative earth then the wire from F&D goes to the positive battery terminal and the circuit is completed by holding the dynamo's body on the negative battery terminal. You won't need to do the motor test if the dynamo passes the voltage test mentioned earlier. If it does pass the voltage test on the bike you need to check out the voltage regulator next as the dynamo should be ok. If it doesn't pass the voltage test the dynamo is the problem. Try re-polarising it and doing the test again. If no joy remove the dynamo and try 'motoring' it. If it motors ok but in the wrong direction you may find that the field coil wires are reversed and need their terminations swapping (don't ask how I know !). Good luck with it.
Keith.
Lucas_Generator_E3L_E3LM_E3N.pdf
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JohnnyBeckett
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Re: Charging issue with 58 Huntmaster

Postby JohnnyBeckett » Mon Sep 14, 2020 10:28 pm

hi nick you need amps as well as volts to charge a battery i have had batteries that go flat wen they got hot and wen they cool down then they seem ok you need to get a load test on the battery :?:

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Richard Kal
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Re: Charging issue with 58 Huntmaster

Postby Richard Kal » Tue Sep 15, 2020 12:12 am

Check the drive sprockets ( especially the small one on the dynamo) aren't slipping on the tapers.
Richard

Nickfrank
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Re: Charging issue with 58 Huntmaster

Postby Nickfrank » Tue Sep 15, 2020 10:32 pm

Thanks everyone for the comments. Some of what you suggested I’ve done already but lots of helpful tips here. Will get stuck into it and post back with results!
Nick


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