Good news! You'll easily get more than 3 hours of gameplay on 4x18500s with a Hollywood 2 and Thundervolt! UltraWii Sakura had 5.5hrs on the same battery configuration, and that was with a Hollywood 1 and no undervolting. Undervolted HW2 uses ~3.3W, vs stock voltage HW1's ~5.3W so you could be...