I have not yet driven my California in the dark but have to wonder whether the alternator is really up to generating enough energy for the main beam plus spotlights at 3k Rpm. Do people fit a switch to be able to turn them off? Some bikes have their spots on all the time, this also seems a good idea, BMW tourers seem to cope. Is rewiring the spots an option?
A simple test would be to put a voltmeter across the battery, preferably an older dial type rather than a digital one. Start the bike up and watch the voltage with the lights on. It should reach over 12V. With the lights off, it should go up to around 14Volts, less with the lights on.
If you are worried, you could fit LED spotlights that would draw a very small ampage.