It all depends on the brightness level you use during the tournament. We have seen roughly 8-15% drain during a two day tournament with G90 with a 5 second delay. During a two day G90 with a 30 second delay it was about 15-20% drain. If you are running low, the operating system will automatically activate the battery saving mode as well. One thing to note about the ChessNoter N6 is it has a very large 3220mAh battery and the ChessNoter N9 had a 6700mAh.
- ChessNoteR N6 can last up to 8 hours in tournament play and has a quick charger to get to 80% battery life in 15 minutes between rounds
- ChessNoteR N9 can last up to 13 hours in tournament play and has a slow charge that cane take 4 hours for a full charge
If you are concerned about battery life, you can always purchase an external battery pack from places like Amazon, Wal-Mart, Best Buy or eBay that use a Micro USB Cable.