Sportdog 400S e-collar

Good morning. I was wondering if I could get some of your help with an ecollar. I just bought the Sportdog 400S ecollar to work with my yellow lab. I bought it on Saturday, charged it for 24 hours as instructed, and used it for the first time on Sunday. The collar has 8 levels. He responds well to 1 or 2 depending on the situation. I've been working with him for about 30-45 minutes twice a day for Sun, Mon, and Tues. He's been very obedient and responsive, and has really seemed to enjoy it . . . no complications. We went out this morning and I could not get him to respond. It was if the collar wasn't working. I rechecked the fit, and just like the DVD said, it was tigh enough to stick one finger under ther collar. So, I went up to 3, and he still wasn't responding. I finished the walk and took him back inside. We were in the elevator, and I told him to sit. He didn't respond, I used the collar, now on 3, and he yelped.

The collar is supposed to be good for 20 hours, and the transmitter for 40, on a full charge. I haven't charged since Sunday, but like I said, I've only used it about 4.5 hours, and I turn it off after each use.

I'm wondering if this needs to be charged more frequently, or maybe this transmitter is weak (though I was only 25-30 feet away before the elevator). Has anyone used this collar? I'm wondering if its an inferior collar, and maybe I'd be better with Dogtra or something else. The people at customer service weren't very helpful.

Any help would be greatly appreciated.

Pete :help: