I'm going to do several tests on my DS which will show the amount of battery life it has while playing on the CycloDS. I just did one recently even though I didn't played it Non-stop. I however, kept track how many hours, minutes I had played. Also let me reassure you that I didn't touch my DS until the following date, which was fully charged at that time. Here's Test 1 so far... Test 1. Date: 6/25/09 Playing: Knights in the Nightmare 5:10PM-9:24PM 4 Hours 14 minutes Date:6/29/09 Continue Playing: Knights in the Nightmare First sign of it going red at 6:06PM. 5:21PM-6:06PM 45 minutes Battery life on red till it finally died, I just beaten Capehorn but I didn't save -.-. 6:06PM-6:57PM 51 minutes Today's total of battery life. 5:21PM-6:57PM 1 hour 36 minutes Total Battery life on Electric Blue DS Playing: Knights in the Nightmare CycloDS w Battery Saver feature Total: 5 hours and 50 minutes Test 2 will be doing a different game, Knights in the Nightmare without the battery saving feature.