I use an 1100 mah 4 cell in my EZ Glider and it's great for at least 2 hours of sloping. I'm running 2 HS-81's and 2 HS-56 servos. I do a lot of aerobatics when the wind is good, so I'm constantly on the sticks and have not experienced a problem. That 700 mah 4-cell should be good for at least an hour. Battery packs are cheap and you'll find that you need the weight in the nose on an EZ glider anyway, so why not go with a 1500 mah? I had to add 2 oz to the nose with the 1100 Ni-mh pack. You're going to enjoy flying the EZ glider as it is one of the most successful Multiplex designs ever. Have fun and soar high!