I used to use the sleep mode on my DS lite all the time. I'd play for 30-60 minutes a day, closing the lid for sleep mode in between play sessions, rarely actually powering off. I'd only have to charge the device every four or five days. It was beautiful. Then I got an M3i Zero, and it would run the battery down to flashing red in only 8 or 10 hours of sleep mode. Ugly. So: Is there a flashcart out there that works well with the DS lite in sleep mode? Five days might be hoping for too much, but is there one that can do 36-48 hours of sleep time? Is there one that can sleep similarly well for the 3DS?