I went for a ride tonight and got a couple blocks from home and the bike died. I noticed before it died that when I put on the brakes the headlight would dim considerably. The bike would not start at all and none of the lights worked. Would not jump start when rolling down a hill either. Got it home after much effort ( I live on a hill) and tested the battery, the meter read 13.3 volts. What should I check for next?