regulator

Hi there,

I am from hungary and I ride a cbr600f4 2000. I never had a problem with it until this summer. When my ventilator came on my bike stoped. However I took the generator to a specialist and that works just fine. As it turnes out the charging system is pretty easy on these bikes. Generator, regulator, battery (so they say). So I bought a new regulator but that just killed my battery. I bought another one (thinking that it was bad in a new condition) and I bought a new battery. But it's still tha same overcharging. itdoesnt seem to be regulating the alternator voltage. its around 15v at idle, and up near 20v when i rev it. I asked around here in hungary but nothing really. If you know what would help, please write.

they are a simple system like you said
15 V at idle is a bit high, but not terrible
20V at higher RPM is obviously gonna over charge the battery
and some of the electronics may not be too happy with it either

of course the regulator portion of the rectifier/regulator is supposed to control this
current in excess of what is requited to charge battery/run auxiliaries
is supposed to be dumped off as heat, this appears to be not happening

I suppose it's possible that a wiring problem could cause a control issue with regulator
that and maybe you have the wrong regulator

I'd check harness connections and grounds for the green fuzzies or broken wires
anything else been changed electrically on the bike?

Your alternator outputs AC (alternating current) and plenty of it at anything above idle. That power is rectified and regulated, the rectifier changes the nature of the AC output to correspond with your battery requirements which is DC (Direct Current) and your regulator limits the output voltage to correspond with your battery requirement which is ~12 volts DC (usually closer to 13 or 14 volts DC when measured with no load applied). Check your rectifier. Rectifiers use a diode and diodes are very susceptible to failure when they over-heat.

... moderators will likely be along shortly to move this thread to the technical forum area.

RECTIFIER, REGULATOR Part # 31600-MV4-010
They are notorious for failure, use genuine Honda replacement only.

Thank you,

I dint think that it could be a wiring problem. I'll check it. Thanks!!!

Yes, the ventilator works just fine, the bike feels just like before, strong and quick, since I have replaced my regulator and battery the first time (by the way it is the 3th time). Unfortunately I had to replace my batteries 3 times as well because now I cant stop the overcharging problem.

Motorcycle batteries do not have a very long life expectancy, typically 4 years would be reasonable in my experience. My concern is that you have the meter setting on AC volts instead of DC volts, is that possible? Measuring AC voltage on the output side of the regulator/rectifier will give an incorrect reading.

If the output to the battery does exceed the voltage significantly that would indeed harm or even boil the battery and possibly blow the main fuse. Most likely cause of that would indeed relate to the part that TK4 made reference to. Be careful with handling of the battery, they can explode or cause fires.

You should also do a resistance check of the stator output wires. Typically there will be 3 yellow wires coming from a 3 phase alternator stator, typically all of those 3 wires will have the same resistance reading of only a few ohms. If a stator winding is live shorted, that can increase the input voltage to the rectifier/regulator.

... hope this helps some.