Minecraft wiki entry for Creeper, associated text: Their countdown timers are the same as normal creepers, both in terms of range and time. With a power of 6, an explosion caused by a charged creeper is twice as powerful as the explosion caused by a creeper. Charged creepers' explosions are 50% more powerful than an explosion of TNT. How close the creeper was to the lightning strike does not affect the size or power of the explosion.