1, replace the new battery. Trolley speaker battery is not effectively protected, making the battery aging, can not store electricity, resulting in the sound like diarrhea. Batteries are not very expensive, dozens of dollars can be dealt with, but you need to purchase the same voltage and current batteries to avoid burning the sound.
2, to professionals through the high voltage to activate the battery, of course, there are some can not be activated. Can not activate the case need to replace the battery.