Join Date: Nov 2018
Location: Gloucester, VA. & Manassas VA.
In the Kawasaki Versys forum there are very detailed explanations of stator testing and why they go bad. It will also recommend an OEM stator. Short test is to warm up the bike, unplug the stator connector and use a A/C voltage tester on all 3 of the leads. A to B, B to C, and C to A. Use your idle speed adjustment to raise the idle to about 3000 rpm. You can't hold the rpm stable enough with the grip throttle. This will have your stator at less than full output but above idle output. All three of the reading should be the same within 0.1 or 0.2 volts. This test is on the unregulated leads direct from the stator.
That said your description sounds like a bad battery. I have voltage monitors on my bikes to keep track of the condition of the battery and charging systems.