Flat Battery Again

[Bill Cannon]

No ancillary outlets just lights, stop light and idiot lights. Indicators had been fitted but I removed them.
It has Lucas RITA EI and never had the tell tale firing at fully retarded which they normally do when the battery voltage charge starts to drop.
I bought the machine through a middle man so history is only what I have gleaned from supplied paperwork, John Renwick whom I had the opportunity to speak with briefly and others that have recognised the machine and 'know' a little of it's history. John Roberts (?) ran the motor in a grass track machine in the Horsham area, this would at least explain the Norton gearbox.
Hopefully people are not being misguided by mention of the 'Kubota' alternator. I can't find any reference to this in the paperwork so believe I have repeated what an observer told me. All I can say is it appears to have two wires coming from it and the laast time the battery discharged and was recharged , placing a meter across the battery terminals indicated it was receiving a charge.
The battery has been recharged and is connected and all I can say is that in the last 3 hours it has not depleted.
See attached blurry photos that will only give a rough idea of fitting and physical size of the alternator. Not very helpful I know, but if anyone can make any knowledgeable observation of what alternator it may be if this appears to be a standard up grade I would be grateful. Thanks for comments up to this point.View attachment 35914View attachment 35915View attachment 35916

It looks the same as my Kubota 14A permanent magnet alternator. Same as used in the MacDouglator.

 

[Peter Holmes]

I have found that if you wire in the "idiot" light on these systems that they draw about 45 milliamps and if left to their own devices will eventually drain the battery. I had this issue with my system and determined to find the cause took an inline ammeter and started chasing things. Eventually found a wire drawing about 90 milliamps. The first disconnect was the feed to the TomTom which has a built in 12V - 5.7V transformer that stays on, dropped the draw in half. Next I dropped the "idiot" light and all went to zero. Ever since then I put a master switch on the ground side of the battery which made the problem go away.

I use a Garmin satnav, I would have preferred the TomTom, but the Garmin was a gift and I am sort of stuck with it, but if we assume the two devices are similar in terms of current draw etc. would you still expect a continuous current draw even if the device was removed from its cradle, which is where the unit gets its current from, or is the current taken continuously by the cradle and pre cradle gubbins, irrespective whether the satnav is connected or not.

 

[Bill Cannon]

I use a Garmin satnav, I would have preferred the TomTom, but the Garmin was a gift and I am sort of stuck with it, but if we assume the two devices are similar in terms of current draw etc. would you still expect a continuous current draw even if the device was removed from its cradle, which is where the unit gets its current from, or is the current taken continuously by the cradle and pre cradle gubbins, irrespective whether the satnav is connected or not.

The TomTom problem has been long standing and invalidates the warranty if fitted to a BMW. BMW use Garmin adapted for their use. If you use the BMW version there will be no problem, I don't know if there is a problem with the Garmin version unfortunately. Of course most Satnavs are intended for cars where a tiny current isn't much of an issue.
Cheers Bill

 

[Comet Rider]

Hi Bill,
It's not the Sat-Nav per say, but the cradle.
As most vehicles are 12V and the Sat-Nav's 5V you need some form of voltage dropper, and if wired directly to your power supply they will always be converting the 12 down to 5V hence a parasitic draw.
I know for BMW that the Sat-Nav's usually a fed from a switched live/Can Bus feed

Also for a normal wet Lead/Acid battery it will naturally loose charge if left to sit

HTH
Neil

 

[Robert Watson]

As I said (maybe not as clearly as I should have but)I found a draw of about 45 milliamps just from the transformer in the cradle.

 

[brian gains]

another 100 mile ride and on return could barely raise a 'parp' from the horn, although did recover slightly after 5mins parked up.
Using with a little knowledge and not much understanding both an analogue and digital multimeter the battery volts rise to approx' 14v with increase of motor speed, direct output from alternator (two wire?) indicates 35 - 40 ACV.
Following Robert Watson's suggestion I'm going through this like the Apollo 13 mission, replaced ludicrously high powered headlight bulb with 60/55w , disconnect sidelight bulb , next will be rationalise twin tail lights into one lamp.
The ammeter fitted has a LED incremental series of light display and goes into the red / negative soon after start up, would LEDs sap more power than a regular ammeter?.
The battery is rated at 6Ah.I've been tieing my gourd in knots trying to calculate what the draw is of two twin spark Dynatek coils.
At present I'm considering that the battery is not large enough or the regulator is duff/ not giving sufficient output to meet higher loads.
Hard to diagnose faults over the interweb but any further considerations would be appreciated.

 

[Bill Thomas]

We still don't know what alternator you have Brian, My bet is an old type,
2 ign' coils do use a lot , But when it's running it should be OK,
Don't think it's the battery size because I only use 4 amp 12v type, and that's with a Mcdougleator,
With 2 6v coils ie Lucas Rita ignition.
And the same battery with a 12v Austin Mini Alternator and "D" Distributor .

 

[Chris Launders]

Splash out a few quid and buy something like this, you could couple it in at the battery and it would show charge/discharge current and voltage, just be sure to disconnect when leaving the bike stood for any length of time as the illumination circuit would have a power draw. You could also fit it straight after the regulator to show what that is producing but you may need a higher rating one.

https://www.ebay.co.uk/itm/Digital-...711724?hash=item23d55103ac:g:A38AAOSwvR5aSQVw

 

[Bill Cannon]

another 100 mile ride and on return could barely raise a 'parp' from the horn, although did recover slightly after 5mins parked up.
Using with a little knowledge and not much understanding both an analogue and digital multimeter the battery volts rise to approx' 14v with increase of motor speed, direct output from alternator (two wire?) indicates 35 - 40 ACV.
Following Robert Watson's suggestion I'm going through this like the Apollo 13 mission, replaced ludicrously high powered headlight bulb with 60/55w , disconnect sidelight bulb , next will be rationalise twin tail lights into one lamp.
The ammeter fitted has a LED incremental series of light display and goes into the red / negative soon after start up, would LEDs sap more power than a regular ammeter?.
The battery is rated at 6Ah.I've been tieing my gourd in knots trying to calculate what the draw is of two twin spark Dynatek coils.
At present I'm considering that the battery is not large enough or the regulator is duff/ not giving sufficient output to meet higher loads.
Hard to diagnose faults over the interweb but any further considerations would be appreciated.

I have twin/twin Dynatek coils. I don't know the current draw but it is very high as I have had to upgrade the earth wire to the coils as it has burnt out twice. But I doubt that is the cause of your problem.
Cheers Bill

 

[Bill Thomas]

Didn't they have a lot of trouble with regulators or whatever they called them in 70s,
Zenner Diodes ???.
If you could show a photo of that, Someone might be able to help,
Could even tell you what type of alternator was used,
What did you find with pos' earth, Was that right ?.