If you are having to leave your Socket Mobile Bluetooth Scanner in the charger for it to work, you need to replace the batteries.
Its easy to do. On the back of the scanner is the round lanyard attachment. Take a key or coin and turn this 90 degrees, so its sideways like this pic, then the cover can be removed. You might have to wiggle it a little.
Then you can replace the two AAA rechargeable batteries.