Charging

[chris goldson]

Good afternoon

When I first bought my model 30 it would charge OK for a little while then stop. Adjustments to the old type regulator would do the trick until I took it out again.

Did the dynamo check according to the manual and it was working OK so put it down to the regulator so have purchased a solid state type hoping to resolve everything.

Four hours later still scratching our heads as have fitted everything and only now a very small charge and with the lights on a large discharge. Have returned unit as don't know if this is the problem but as I said earlier it did show a good charge (but not for long!) with the old one.

It is a new battery too any thoughts would be appreciated.

[spookefoote1956]

Could be a duff unit. If you say the dynamo is working properly then it may well be the regulator. I use a DVR2. Spot on.

[Groily]

Couple of questions for you.
Your dynamo check according to the manual consisted I imagine of joining F & D at the dynamo and putting a bulb (or meter maybe) between them and earth with the motor running? And presumably it lit up and got brighter with revs?
If so, that's good.
You don't say what sort of regulator you've fitted. Presumably it has the correct earth for your system? (They are sensitive to polarity.)

When the dynamo was connected to the regulator, did you check if there was anything coming out of the 'A' wire from the regulator? There should be a voltage that rises and then stabilises at 7 to 7.5v, which it should get to at moderate revs.
If the dynamo is chucking out plenty and the regulator is the right polarity, but there was nothing coming out of A, then there's a fault with it - or with the wiring from dyn to reg, or with the regulator to Earth wire.
If there was a charge coming out of A, but the battery wasn't getting it and the ammeter wasn't showing it, then there's a wiring problem. (I don't think that sounds very likely if it has worked in the past, but switches and connections can go funny on us, and often be intermittent, so it's possible.)

The first things I'd check when you get the magic box back - or another one - are the F and D connections to the regulator, its earth to the frame, and whether there's anything coming out of that A wire to the ammeter / switch and thence to the battery with the engine running.

If, perchance, your system is negative earth, and the regulator you fitted is one of the Wassell electronic ones, then the dynamo wiring would need to be changed to suit it. The instructions supplied have been accused of being a bit confusing before now, but I think recent ones are meant to be a bit better.

[chris goldson]

Many thanks for this

The reading when we undertook the F & D test fluctuated up to 14 but the highest we ever got from the test coming from A was 6.4 irrespective of the revs.

The unit I put on it was DVR2.

Once again thanks for your help.

Best wishes


Chris

[G15 Roy]

Many thanks for this

The reading when we undertook the F & D test fluctuated up to 14 but the highest we ever got from the test coming from A was 6.4 irrespective of the revs.

The unit I put on it was DVR2.

Once again thanks for your help.

Best wishes


Chris

Don't try to send the DVR2 back as faulty he will just tell you that you fitted it wrong his customer service is Bad.

[Groily]

The reading when we undertook the F & D test fluctuated up to 14 but the highest we ever got from the test coming from A was 6.4 irrespective of the revs.

Hmmm . . . I'd expect to see 20v + with an E3L with a few revs and no loads on to be honest. 14v (especially with no loads on) would barely support a system running at 12v, which the dynamo can easily do. (Normal regulating voltage if running at 12v is 14.4v-ish, and that has to be maintained (at revs) when things are switched on as well or the battery won't charge properly. Fully charged, a 12v battery should actually show 13.2v or near as dammit.)

If your 6.4v was with the A line connected to the ammeter I'm guessing you were seeing just the battery voltage probably.

If the battery was disconnected and you were getting that 6.4 tops from A to earth, it could be because in fact the dynamo isn't really delivering. What's it like if you put proper loads - like a 40W-odd 12v bulb - between F&D and earth? Should light it very brightly by about 2000rpm engine, and maybe blow it if you whack the revs up for long.

Not sure quite what to think to be honest, but I don't think anything can be ruled out!

[chris goldson]

Meant to add it is still operating as a 6v system

[SPRIDDLER]

This is my test rig with a 55 Watt load (9 Amps on a 6V system).
I use a 12V lamp as there's less chance of it blowing. It will light very brightly with a good dynamo even on a 6V system.
It works equally well on a 12V system.
The lamp will blow doing the test if you wind the revs/dynamo output up high enough.

Dynamo test rig (640x480).jpg

Link 2 (640x407).jpg

[chris goldson]

Thanks for all the help much appreciated.

Slightly tempted to buy a replacement MCR2 rather than try again with the solid state unit as at least with the old one it did charge though mysteriously would stop after a run up the road. Any thoughts where I should go for a dynamo replacement/overall if it proves to be the problem and is it a pain to remove?

[dave16mct]

Try Paul Dunn : www.dynamosdynamos.co.uk

Very easy to remove. Undo the nut on the drawbolt, which is the odd one on the timing cover. Slacken the clamp and pull the dynamo out. Stick with the DVR2 regulator.

Dave.