Wasn't sure where this should go...
My car has started doing something weird.
The volt meter will 'bounce', at random times.
Not drain voltage, but bounce very quickly from 14 to 15, and sometimes 16 volts.
It appears to affect my instrument and headlights, ruling out a faulty gauge.
It's only started doing it recently, about 3 weeks after I installed a new battery ('High-Performance' Century), so I doubt it's that.
I also can't replicate it.
I've tried fiddling with the earth strap, turned off/on the stereo, wriggling random cables, hitting bumps intentionally to try and vibrate whatever it is causing it.
Still can't find the trigger.
Could it be the voltage regulator thing on the alternator?
If it is, why is it doing it intermittently?

I'm going to put a better earth strap from the battery on anyway, so hopefully that solves it, but somehow I doubt it.
Any ideas guys?