As George said, particularly in stop and go traffic and/or if you take a lot of short trips, it's possible that your battery could be good but still have a low state of charge. You might try checking your battery voltage (any digital multimeter will do) first thing in the morning: it's fully charged when the voltage is 12.7, 90% at 12.5V and only 50% at about 12.0 V. Plugging in to a battery maintainer might be in order, especially if you take short trips and have accessories like auxillary halogen lights and heated gear. If it doesn't hold a charge, replace it. If charging doesn't help, then have it load tested. Also it's prudent to check the connections at the battery - loose and/or corroded connections can introduce resistance that can mimic a bad battery.
What happens in the helmet stays in the helmet.