My Losi randomly died on me today and I noticed the battery was reading 4.8 volts. I'M running the stock battery. After charging it for several hours volts got to 5.1 and it started but died and went to 4.9 volts. I then checked for spark and didn't have any. How many volts are needed to create spark on these. I want to get a lipo but don't want to have to upgrade the throttle servo. Please let me know what you guys think.