I have a 10 month old Napa 400 cca battery in and have been having some starting issues when not on tender. When I have driving lights etc off while running I am getting 13.5V at idle and when they are all on I have 13.1 V. With meter on battery while starting voltage drops drop to 12V. While idling shouldn't volts be above 14V. I do have cheap $100 meter? Any ideas which way to go? Thanks!

 

above 13 at idle...lower than 15 at higher RPM. I always start with a good shake down ride watching all gages and thinking cause/effects....check connections and look for worn spots for possible shorts....I'm not a gifted forensic genius and cant point out exactly what the problem is like some can on here, only give insight what I would do.

 

you should see no more than 14.8 volts at the battery when above 3000 rpms. idle voltage reading will bounce around, you may see 10 volts when you hit the starter


charge your battery fully- with a battery charger- pull it and load test it- ask napa.

while it is out, check that your cables are in good condition, and tight at both ends

mike

 

2000 rpm is voltage checking from alternator 14.8 or so. Ignore idle voltage, just not enough AC from alternator to make enough DC charge.... After a good 24 hour maintenance charge, unhooked and another set overnight , should be 12.7 or so. If still a question, charge, pull it out and get a cold crank amperage test at NAPA or Autozone free. Doing this insures what you have and gets new good connections. Harleys loosen the connection all the time.

 

There are a couple of Stickies in the Tech Electrics section on checking your charging system. Use a multimeter for testing, don't rely on a bike gauge, as they aren't accurate enough.