The BSA A7-A10 Forum

Technical => Lucas, Ignition, Charging, Electrical => Topic started by: wade-o on 14.11. 2008 00:20

Title: Charging Question
Post by: wade-o on 14.11. 2008 00:20
Hey Its Wade and I have a charging problem. It seems to charge fine for about three minutes then the gauge takes a dive and does not seem to recover, When a magneto works for a few minutes  and then quits the windings are what get the blame . But if I read old post right , When a gen. quits It sound like the voltage regulator is the culpret ?  Yes No? Help !
Title: Re: Charging Question
Post by: RichardL on 14.11. 2008 00:49
Can be a variety of things, but it seems common (particularly for me) that when the ammeter stops indicating it is a sign of a battery destroyed by getting too much current, due to bad or out of adjustment regulator. On the Home page, search for "DVR2," which is the regulator I and many others here have purchased and use successfully. One of our forum members, "Manormike" is the inventor (who is far from self-promoting) and, I suspect, will chime in to offer real knowledgeable advice.

Richard L.
Title: Re: Charging Question
Post by: beezalex on 14.11. 2008 13:29
I just ordered the DVR2 after my podtronics took a dump after what I assume was a short.  Mike promises protection against such events.

Wade-O, does the ammeter show a discharge after a few minutes or does it just not show a charge?  Remember that with a fully charged battery and the lights off, the output of the generator is regulated to essentially zero output and will not show a charge.
Title: Re: Charging Question
Post by: wade-o on 14.11. 2008 13:57
No sir it goes to the negative ,until  I turn everything off
Title: Re: Charging Question
Post by: groily on 14.11. 2008 16:29
Well, either the dynamo isn't dyning, the regulator isn't regulating - or possibly the battery has died. However, if the battery has died or become disconnected, the lights should come on with the engine and brighten with revs until the regulator regulates. There may or may not be any sign of life at the ammeter in those scenarios depending on exactly what has happened. Sounds to me as if you have things connected up OK, but there's no charge.
Suggest you test the dynamo first. An easy test is to disconnect the F and D connections at the dynamo. Make a wire bridge between the 2 - on the dynamo! - and take a wire from this common bridging wire and stick it to the metal body of a bulb. Start engine. Touch the pole of the bulb to a good clean place on engine or frame with the engine running. If the dynamo works, the bulb should light up. It should get brighter with revs. If you rev it too much the bulb will blow due to excess volts. There's a pic here on site somewhere of just such a test rig. If the dynamo passes that test, the fault probably lies with the regulator.
If the dynamo doesn't work, the easy things to check are the brushes. Are they clean and not stuck in their little slides? And you should clean the commutator they sit against. Often, the thing will work again for these little bits of attention. But not always for ever if things are very tired.
Expert advice will be at hand I am sure, and as Richard (Manosound) says there is a fair bit here on the general subject.
Like others, I am a DVR2 fan as well. Excellent solution if that's your problem, and very easy to install. I've got 3.
Title: Re: Charging Question
Post by: RichardL on 14.11. 2008 17:34
Groily has done a fine service by encapsulating the test procedures for finding real fault.
Title: Re: Charging Question
Post by: Brian on 14.11. 2008 21:04
All very good advice.

The only thing I would add is that it really is worth going to your local electronics store and buying a cheap ohm/voltage meter. Get one that shows ac/dc voltage and resistance. They are usually very cheap. If you are not familiar with this sort of thing I would go for one that has a dial rather than a digital readout, I think they are easier to read than digital if you are not sure what all the numbers mean. I would also suggest getting a couple of pieces of wire about 1metre long with small alligator clips on each end, very usefull. Its a small piece of equipment that wont cost much but is very handy.

If it does turn out to be the regulator I also recommend the DVR2, put it in the bike and forget about it.

Good luck.   

Title: Re: Charging Question
Post by: wade-o on 16.11. 2008 15:15
This is all very good info. I have one more  question before I make a bulb with 2 wires(wiggy). If during the minute that all seems well, the headlight looks to brighten when I blipp the throttle then am I looking at a reg problem and not a gen quits when warm problem. Does that sound right ? I haven't been out to the ole shed yet , (Honey Doo stuff)  If the answer is maybe then out Wiggy making I go. Thank you all for your support
Title: Re: Charging Question
Post by: groily on 16.11. 2008 22:22
Think the answer has to be that useless 'maybe'. It's encouraging that the lights brighten for the first minute or three - there are signs of life in there somewhere. but quite why it then dies could be because the generator starts to sulk, or the regulator does. Think I'd run the basic tests to see what can be established, and take it from there. The good news is that no matter what's wrong with the system, it can be fixed and made pretty reliable, reasonably easily.