1980 Honda CB 650 - Battery does not recharge when riding.

[HazMatt]

After charging my battery overnight, and making sure it is fully charged and ready to go - I'll ride for no more than 20 minutes, when the bike begins to sputter and turn off intermittently. When I check the battery, it's dead.

I'm not sure how I can tell if it is a rectifier issue, or a charging rotor issue. Before I begin buying replacement parts, I'd like to have a better idea of exactly why it is not returning power to the battery when I ride.

Any thoughts? Thanks!

Matt

 

[robert danger]

Start by checking all the connections between the stator and the rectifier.
I had the same problem on my 350, turned out it was just a loose wire.

 

[ratty175]

Try using this flowchart from RaceTech to help out with your diagnostics. I think this chart is super useful and pretty easy to follow. Let me know if you end up with any specific questions. Good luck!

http://racetechelectric.com/files/pdf/rte_troubleshooting_flow_chart.pdf

 

[Nitsuj]

Easiest way to tell if it's reg/rec is to start at the battery and work your way back. Start with the bike running, put a meter on the battery. Slowly bring up the rpm. Voltage should climb to charging voltage as you get up close to 3000rpm. Take the meter, switch it to AC current and check the wires coming out of the stator. I don't remember what the voltage should be at the stator, but it will be higher than the DC voltage. I want to say 35 volts, but, it's been a while. Look it up.

Out of spec at the stator means the stator is bad. Good voltage from the stator wires means the reg/rec is bad.

 

[midgtmn]

For my bike at least, there is a relatively simple check of the stator coils by measuring their resistance (ohms) with a multimeter. The factory service manual for my bike includes the proper ranges for the stator coils, if they are out of that, it won't be working.

Also, in the post above, I don't think Nitsu meant

Take the meter, switch it to AC current and check the wires coming out of the stator.

... don't check current, stick with checking the voltage, like the guide posted by Ratty175 says. Failing those checks, check the stator coil resistance if you can find the original specs.

Very good guide though, Ratty. Thanks for posting that up.