I hear about a lot of confusion with regard to the testing of the battery, charging system and voltage regulation, so i've decided to do a quick video about this. This requires a voltmeter. You should have one.
The first check is really simple, the check of the battery voltage itself in the rest position. Followed by the battery voltage when the ignition is turned on, showing that it will drop but can hold its own even with the draw, a draw that will later be measured.
Second is a demonstration of the running engine, demonstrating the functioning voltage regulator in play. Mine sits around up to 14v as expected regardless of engine RPM.
The next test required more caution so the key is removed from the bike and the ground from the battery is disconnected so that current can be measured across ground to check for any system leaks or unexpected current draws. I use my under tank light to demo what a leak looks like.
I use this time to demonstrate that the idle current is about 6 amps for a vstar. If I hit the starter I would have obviously blown out the meter. DONT HIT THE STARTER. DONT!!!!! DONT!!!!!!!
Putting everything back to normal and moving back to normal, I show how voltage drops as the starter turns. A healthy battery may jump down to low 11's. A bad battery may turn the engine, but not turn the engine and run the ignition at the same time.
Finally, there are other signs of failing charging systems on the road.... this is discussed as well.
