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Power loss

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When I do a current test by inserting a multi meter in the circuit, my 1936 Model 18 is using about 60mA despite everything being off. I noticed that the battery was slowly draining over a few days so did the test. I've tried to isolate the cause but despite removing the lights and horn from the circuit it's still draining power. I've bench tested the battery over a couple of days and it holds power fine.

I had the dynamo converted from the original 3 brush to 2 so installed a Wassell voltage regulator but otherwise the layout and units are original (it was rewired in 1993 but whoever did it only used black wires presumably for authenticity but doesn't make tracking very easy.. did they not use colour coded wires in the 30's?) 

Anyway, does anyone have any thoughts as to where I should be looking before I start dismantling it in a big way ? 

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Disconnect the Wassells regulator, been a couple of reports of their alternator rectifier/regulators leaking to earth and I may have one doing it too, so maybe the same dodgy electronics is in their dynamo regulator. 

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On my WD16H, I added a fuse on the battery to earth lead after a MCR1 fault killed the dynamo and the battery. If you do the same, simply removing  the fuse  when the bike is unused should be an easy fix. Otherwise the regulator seems the most likely culprit.

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I have had a Wassell regulator fail also. It was drawing 20mA, enough to kill a battery if left unattended.  Al Osborn will test your regulator for you if you send it to him.

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The above advice all sounds spot-on. The mechanical regulators of course had a cut-out fitted.

I don't know about the civilian bikes, but I have an original 1939 WD harness and apart from the dip switch wiring, it was all black but with small coloured rubber bands at each end as colour coding. This is my impression of it using shrink-fit.

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I used one on an A10 and it seemed to work fine, but I didn't have the bike long. I suspect their quality control is poor if it exists at all. An electronic device should have a diode in it to stop reverse current flow.

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Thanks all for your advice. I'm so confident that you're right that I've shelled out for a Dynamo Regulators DVR2 and I'll replace the Wassell. I'll post another comment on the result once it arrives and I've installed.

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Fitted the new regulator and retested. It still showed 1mA on a circuit test so I've gone back and asked the manufacturer. It seems such a small reading I'm not sure I should be bothered about it but it would be nice to know why. With all the wiring exposed I've taken the opportunity to check the electrics back to the wiring diagram. About 3 yards of redundant wire removed, connectors replaced where needed and the loom re-wrapped.. it's now a thing of beauty... Thanks again for all advice...

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A 1 mA leak is not much, but will of course make about 0.7 Ah per month. Batteries has some internal leaks, more for older ones, less for new ones. So the best approach is to charge them a couple of times a year. Either by using the bike (fun) or use a charger (annoying).

A bit off topic, Modern cars with all their fancy electronics always draw some current, so don't expect them to start after a month or two unused. Luckily we have not that problem with our magneto and kickstart machines.

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Thanks Mikael

I'll try a spare battery and see if the leakage is still there but as you say, it would be solved by regular use... won't be today though... I'm not keen to ride around in a gale... 

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1 mA wouldn't bother me. It could easily be a slight inaccuracy on the meter. Even if true, a 4 Amp/Hour battery would take 4,000 hours to go flat.......

hello  yes I would go for the Wassel regulator first and give it a good checkout  but you may have something making contact to ground some were ,   check every joint  and component    yours anna j       

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Wassel poor products-no technical back up. Can't be the battery, JC- Batteries do not generate leaks, the leaks take from the battery.

 

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Dynamo Regulators Ltd got back to me to say that there always will be a small current into the regulator A terminal from a battery and with 6 V connection they would expect this current for a DVR2 to be a little less than 1 mA. They measured 2 DVR2's selected at random and both had a reverse 'leakage' of 0.8 mA, measured at 20 C ambient. Temperature is significant in making this measurement as the reverse current through the cut-out diode is a strong function of temperature.

Well anyway my revamped electrics all work well, look a treat and I had a nice run out this afternoon so life is  peachy. Regarding Wassell products, lesson learnt. 

Thanks again for all your advice.  

 


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