I don't have the TV you have but with my set up (see below), the J15 I have keeps it going for 22 minutes. With just the DVR running, it'll run for 115 minutes.
Sony: KDS-R60XBR1 Yamaha: RX-V657/DVD-S2500/CDC-685 Klipsch: RSX-5's/RSX-4's/RVX-42/RW-10
DirecTV: HR20/5LNB Dish WB68 CM: 4221/7777 CinemaQuest: Ideal-Lume APC: J15BLK
I don't have the TV you have but with my set up (see below), the J15 I have keeps it going for 22 minutes. With just the DVR running, it'll run for 115 minutes.
Sony: KDS-R60XBR1 Yamaha: RX-V657/DVD-S2500/CDC-685 Klipsch: RSX-5's/RSX-4's/RVX-42/RW-10
DirecTV: HR20/5LNB Dish WB68 CM: 4221/7777 CinemaQuest: Ideal-Lume APC: J15BLK