alton altenator overcharging

[philip.butcher]

hello help needed with my alton even running with the headlight on it still overcharges by about 5 amps at 50 mph,claimed output of 90 w ?
it has already knackered one battery,i pressume it needs a resistance in the system other than what is in the black box /heatsink? or a set of spotlamps!
would a zenor diode in the system do the job?
thanks in advance philip

[nevhunter]

You have to limit the output by regulating the current in the rotor (normally) It will have 2 slip rings. You have some form of current limiter in the circuit with rotor and that changes the output in the stator which is what's used to supply the bike, It's then converted to DC to charge the battery using a number of diodes. That's also where you get the dc current from to energise the rotor and regulate the output as well. The regulator can be solid state or a older type of cut out and current regulator (unlikely). It's probably beyond the average rider to correct your problem. I'd refer to maker or a reputable bike electrician. Diodes need to be cooled or they fail. Your charge output should be 14.2 or 7.1 Volts for 12 and 6 volt respectively for a lead acid battery.
If it's a permanent magnet it's more crude. Like the Wico Pacy on the early BSA Bantam where the light got brighter as you went faster. Magnets in the flywheel. Nev

[david.anderson]

Philip
I use an Alton with the electronic rectifier/regulator supplied with the Alton. I have never had a problem with over charging, but there is plenty of current when needed. If you have an overcharging problem I would verify it by checking the charging voltage.
The problem could also be loose battery terminals or the regulator, or a lithium battery? A phone call or email to Paul from Alton for a replacement regulator may fix the problem. Forget any idea of fitting a Zener diode. They were a very poor voltage regulator.
David

[Steven.Carter]

Just a daft thought, I guess you've got it fitted to a 12 volt battery. Or maybe a duff one?