The BeginAir is a 4-channel electric trainer from http://www.parkflyers.com and is actually a fairly well-known aircraft that has been on the market as an RTF for some time.

With RTF park flyer aircraft, I had the experience of running into cheap battery chargers that tended to "false peak" while charging the NiMH flight packs. One of my first planes was a Hobbyzone Aerobird Challenger that I affectionately nicknamed my "Aeroturd." I had the same problem where I would charge it up and it couldn't get out of its own way even though my charger said it was ready to go.

I bought the AC wall charger, and that fixed it up. I then only used the 12v car charger that came with it for "topping up" while on the way to go fly it.

My advice? Try some different battery chargers and see if you can't find something that tops up your battery a little better. RTF manufacturers have to cut corners somewhere, and the battery charger is usually one of them. A good battery charger is worth its weight in gold whether you mainly fly electric or if you fly gas/glow.

Good luck and good flying!