Dynamo fiasco

Post by **bmcecosse** » Wed Oct 21, 2009 10:15 pm

I hope it works! I don't think there is anything wrong with the first one !

Post by **guystrungout** » Wed Oct 28, 2009 1:46 pm

Hello again, I just thought I'd update you with what happened about my regulator. After ordering a new one and it arriving( a week later) I fitted it to the car and off went the charging light.
I put a voltmeter on the battery and it was pulling 15v which I am well happy with. I hope thats not too much!
Hopefully I will now be able to listen to my radio and blind other road users with my halogen headlamps both at the same time..!

The only real puzzle is why the original regulator became U/S inbetween me taking it off, fitting another one and then putting it back on again.

Just one of those things I guess.

Thanks for all your help, and keep up the good work.

Post by **bmcecosse** » Wed Oct 28, 2009 3:20 pm

Well - 15 volts does sound VERY high. But is the voltmeter calibrated ? Should be no more than 14 volts. If the battery seems to be 'fizzing' and bubbling - and losing water then it is being overcharged - and will have a very short life. An ammeter of course would tell you right away.

Post by **guystrungout** » Wed Oct 28, 2009 5:57 pm

Well I'm assuming its calibrated, I bought it from Bull Motif, so would be surprised if it wasn't.
What would be the point of selling an uncalibrated rregulator? And more to the point, how do you then go about calibrating it?

My battery will be flatter than usual due to running it with no charging for a good hour or two due to faffing about last week with 2 faulty regulators, maybe it ill drop off when fully charged again? (I'm grasping at straws here...) or is that wishful thinking?

Should I contact Bull Motif and ask them if they sell uncalibrated regulators?

<br>[img]http://mmoc.org.uk/mbimage.php?

Post by **guystrungout** » Wed Oct 28, 2009 6:02 pm

Oops...just reread your reply bmcecosse, and noticed you said 'voltmeter' and not regulator. A clear case of reading what you think is there and not what it actually says.

Don't know about the voltmeter, its only twelve months old and seems to work fine on everything else. How do you calibrate a voltmeter? (I can hear you all with one voice saying 'take it to a voltmeter calibrater') Is there such a person??

Post by **nigelr2000** » Wed Oct 28, 2009 7:01 pm

Yeh it is possible but would probably cost more than the voltmeter to do. When I worked in test and clibration department of an electronics factory when I was a lad we used to have a whole bunch of instruments in a locked cupboard that were used for ONLY such a purpose and god help anyone caught using one normally !!

15 Volts is the maximum voltage for a battery on charge and 13.2 for a fully charged battery off charge (2.2 volts per cell x 6) although normally you only get 13 to 14 when its charging and just topping up with the engine running.

Post by **bmcecosse** » Wed Oct 28, 2009 7:51 pm

I have a cheapo meter from Maplins - it's ok for testing circuits and so on - and indeed it's ok on Mains etc. But - on low volts DC it reads about 2 volts high ( I have a 'good' meter too!) . Try yours on a newish torch battery - zinc carbon - should read 1.5 volts for a single cell. .
And yes - I would wonder if the regulator you have has been calibrated properly. I'm sure in the good old days they would all be setup and tested/calibrated before leaving the factory - but today ........

Post by **guystrungout** » Thu Oct 29, 2009 9:18 am

So there is a slim chance that it was reading 15v because it was charging a partially flat battery?! (still grasping at the same straw)

I've got to go on a good long run today so I'll check it when I've got to the midway point and see if it reads any different to yesterday. I'd better take my bottle of distilled water along to, just in case!

And I suppose it wouldn't hurt to enquire with Bull Motif about whether the regulators are sold ready calibrated.

Post by **bmcecosse** » Thu Oct 29, 2009 11:10 am

I suspect BM will have no idea!

Post by **MarkyB** » Thu Oct 29, 2009 6:29 pm

It will hurt even less to take another reading after the good long run.

I picked up an Avometer that Engineering were throwing out because I like the build quality and the look of it.
My friend who used to be a TV engineer raved about how good and accurate they are so I got him one too.

The chaps in Engineering said that modern meters are better in every way and cheaper too.
No idea who is right but I know a nice looking piece of kit when I see it in a skip

.

Post by **guystrungout** » Thu Oct 29, 2009 9:38 pm

Maybe I'm just being niave but I would be very surprised if regulators were sold uncalibrated. What would be the point? They wouldn't work properly and how many people these days would know how to calibrate one? There is a section in my workshop manual on how to do it but its not something I would be happy to tackle on my own without someone around who might know more about it.

I'll email BM in the morning and find out!

Post by **bmcecosse** » Thu Oct 29, 2009 10:04 pm

I just doubt BM will know! i strongly suspect all that's wrong - is your volt meter. Have you tested it on a torch battery yet ?

Post by **guystrungout** » Thu Oct 29, 2009 10:09 pm

Not yet, but I will! First thing. And then I'll check the mog again.
And then I'll let you know what I've found out.

Post by **guystrungout** » Sat Oct 31, 2009 3:49 pm

The voltmeter reads correctly for a torch battery, and my auto electric friend agreed with you about didgital voltmeters potentially reading wrong, so he has an older one he is going to come and test it with.
I have now heard back from BM who suggest that if the battery draws more than 14v @ 1000rpm after 30 minutes of running then the reglator is faulty and should be returned. I still have yet to carry out this test as I have been busy doing other things. But I will.

<br>[img]http://mmoc.org.uk/mbimage.php?<br>[img ... 04151_8189[/img]<br>

Post by **bmcecosse** » Sun Nov 01, 2009 11:02 am

I agree with that - more than 14 volts will soon fry the battery.

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