Atlas charging check

I have invested in an Oxford trickle charger that can be left connected for extended periods and i could not be more pleased with it. The charge should go through the ampmeter and show a charge when first run . Some bikes run the battery down faster  if left connected  , possibly the 2MC going down . Old batteries run down faster possibly from internal issues.

...Is on my web site, to find the alternator total output, you measure the DC after the rectifier.  The 'Automatic' charges are not a lot of use when there becomes a doubt with 'tired batteries'. You need a real charger to give it a couple amps for half a day. Other wise Graham get in touch direct.

The inteligent  trickle chargers are great for ensuing the bike is ready when you want it. To  comence to  charge a properly flat acid  battery you need an old fashioned  non thinking unit that will try to charge no matter what state the battery is in. But often the battery is sulphated and not in a condition to accept a full charge . They can often be much improved by attaching a de-sulphating device. I  regularly have to charge and desulphate 3 or 4  X 140 amp hour huge  boat batteries  so I have 4  different chargers . A desulphator sometimes takes a couple of weeks to bring an otherwise dead battery back into use . You can rarely get back much more than 80 % capacity . But unexpected  miracles do happen .  I have some 20 year old bike batteries still giving good service. My Transit batteries were fine for 20 years and left with the van .

Graeme, please forgive me if I sound like teaching grandmother to suck eggs.

My usual dodge to check if the battery is being charged is to wait till night time then shine the headlight at the garage door or white fence or the like.  If the light gets brighter when you rev it up then the battery is being charged. 

BTW my atlas which I've just sold, had the original 45/50 w BPF Globe and standard reflector and it gave a superb illumination for night time riding. So good as I had to check that it didn't have a halogen globe!

One other thing, my Atlas would charge to 15 volts which worried me greatly,  so much so that I ditched the zennor diode and replace it with a Trispark unit. I shouldn't have bothered. As it made no difference.  I guess the airgap was at the low end of the tolerance. 

My Atlas was a 1968 model and had come out of a museum and hadn't been fooled with at all, which probably explains why the lights and charging was so good.

Don Anson Melbourne Australia 

In my 'self inflicked' era as an electrical guru I hear a lot of 'trash' at times but Robert is correct and Don is very close. The only point with Dons words is that 15V might be a worry on a 12V but can be tolerated. And the change from the Zener to Reg/Rect. Confirms what I have been saying for years. The Zener system is perfectly adequate with regard control of battery charging. But further-the air gap (rotor/stator) will control the quantity of Amps available but will NOT affect the charge quantity (Amps) as that is the job of the regulator ie the Zener takes away any excess or the Reg/Rect, stops it being available. Also I am saying 15 is tolerated BUT is your 15V real? Cheap digital Voltmeters pick up ignition interference and read 'gobbledy gook' also just look upon the meter as a starting point, in doubt get another opinion(another meter). If you are looking at battery charging don't worry too much about the actual voltage, but you are looking for a rise in voltage, on 12V-2V is expected (3V can be tolerated) .(On 6V-1.5-2v )

My 1963 Dommie has modern rotor and stator.  I added white paint at 30 degrees.  The other marks make no sense to me.

Hi Graham,

I'm not an expert, this is just from many years experience.

1) Yes the airgap is between the rotor and stator of the alternator, and is very important both for electrical output and mechanical clearance so there is no chance of contact between them.

2) Yes it will improve the system by controlling the battery charging and will tidy up the wiring by doing away with the old rectifier and Zener (although they do the job well enough as long as they are working properly and the Zener has a cooling air flow). The two output leads from the alternator go straight to the Yellow leads of the regulator, the Red and Black connect into the system, depending on whether you have Pos or Neg earth, the same as the rectifier is now and do away with the Zener and its cables. Make sure the Reg/Rect output goes to the ammeter so you see the true charge/discharge state.

3) The ammeter isn't interested in voltage (within its electrical safety specs) it measures amps so is quite happy with the 12v from your new system. Just make sure ALL connections are sound and clean. The 'flickers' are nothing to do the increase to 12 volts and will probably be poor/dirty connenctions somewhere or may just be a sensitive meter.

Hope this helps, if any of this is wrong I expect someone more qualified than me will be along to correct it.

Good luck. Stan

No it will not improve the system changing from the rectifier/zener system to a reg/rect. If you have a fault ie no charge, then find the fault and correct it. Changing bits just because they 'might' make thing better is a naf scatter gun approach. The rectifier changes the AC from the stator into DC to charge the battery and run the bike.The zener diode stops any over charging. (provided the zener voltage is correct) The reg/rects are often made in China and are not as reliable as they should be. The final battery voltage (and hence charging) might be better initially. But the Zener system has been doing its job for over 50yrs. Wobbly ametters are down to the crude meter responding to the vibration. Ammeter measure Amps.-they do not concern themselves with Voltage.