This is a common failure because of the way motorcycle alternators work.
Motorcycle battery voltage too high.
A healthy 12 volt motorcycle battery should maintain a range from 9 5 10 5 volts under the load for a good 30 seconds straight.
Measure the battery voltage while the engine is running.
Gassing is bad for the battery and also potentially for you as the gasses are explosive.
The 16v you describe is definitely too high for charging a 12v battery 14 4 volts is a suggested maximum.
Yes a bad regulator will cause your motorcycle battery to be overcharged.
We call this the open cell.
You don t say whether this is on the bike or on mains charge.
If the voltage instantly drops to 0 volts that is also a problem.
In order to get maximum battery life proper charging voltage must be maintained.
If you see something like that right after you charge your battery when re testing you might want to turn the headlights on for 30 seconds or so and re test because batteries can keep a superficial surface charge revzilla photo.
With a voltage between 12 and 15 8 volts dc.
The battery is a little pickier below 13 8 the battery will not fully charge.
Battery voltage too high.
My new battery s voltage from the factory unused read 12 9 v but after using for about half a week of use its holding a.
Either way high or low charging voltage can lead to battery problems.
The old one usually read 12 5 v give or take on a dmm.
One item of note.
The only other battery i ve used for my bike was a regular lead acid battery.
That voltage seems a mite high.
If the battery begins to hold and then steadily drops in voltage there is a problem.