I HAVE A 1998.... AND IT COULD MEAN THAT YOUR ARE PULLING TO MANY AMPS, TRY BUYING A TRICKLE CELL CHARGER FOR AROUND $30 AND WHEN THE BIKE IS NOT IN USE IT WILL MAKE SURE THE BATTERY IS FULLY CHARGED. BEING FROM THE SOUTH I KNOW HOW THE HEAT EFFECTS OUR BIKES. DO THE SIMPLE STUFF FIRST BRO´