Join Date: Nov 2008
Location: Kitchener Ontario
Mentioned: 39 Post(s)
Regulator / Battery Life
Somewhat related as to the shunt regulator is battery life. Something many don't understand. I was recently buying a led brake light used on trailers as I have a gearbrake module and don't wish to change any of my other add ons. I was using our Toyota car, I had a Fluke 189 meter with me and wanted to test this at the store , naturally measuring the current is only useful if you also measure the voltage. I was surprised at the 13.2 VDC at idle and the 13.6 VDC above idle. I wasn't going to bring my scope into the picture but it is related, I have a 4 amp hour battery, so my fast charge puts out 1 amp, which means I need four hours for full charge, if I charge within the scope it takes 24 hours for full charge, using the same 1 amp output adapter, this may be too in depth but here I go, in the case of the scope , it is current limiting so that even with a dead battery it can function, however some use a reduced voltage for charging, which can lead to a reduced capacity / amp hour . Here is the problem, we have a 10 amp hour battery, say starting uses 20 amp for 1 minute = .333 amp hour, which means you need to charge a minimum of 0.3 amp for 1 hour minimum. If you charge below 13.2VDC , it could take several hours to charge the battery, repeating this over a week or more your 10 amp hour battery may be closer to 6 amp hour.
Now the other thing that can happen is over charging, which can be a common problem with the shunt regulator, I have tested several Kawasaki shunt regulator, 2007 , 2008 and 2015, all of them produced a minimum 14.5 VDC and all of them went as high as 15.1 VDC before starting to work /shunt excess voltage ( the shunt is a simple 3 phase rectifier with a shunt circuit to ground, activated by over voltage, a slow increase will produce 15.1 VDC before shunting, which means you could be at 14.9 volts all day, unless you momentarily hit the switch on VDC level, sort of a cut in VDC and a drop out VDC wihch would be 14.4 to 14.5 VDC).
What happens is between the heat of the motor and excess charge voltage , the electrolyte evaporates and your amp /HR capacity diminishes. Using a series regulator, it starts working the instant your stator produces power, and typical volts DC is 14.2 maximum, which explains why my Yuasa batteries last 5 to 6 years on the Kawasaki Versys ( my 07 lasted 6 years and my 2015 is still on the OEM battery)
This is a very basic explanation, many other factors but in reality the worst component of the Versys is the regulator, from what I am seeing it looks like the 2017 1000 ninja uses a series regulator, so Kawasaki is improving things.