The internal battery is a cheap 440 mah lipo but the good news is the case opens very easily and a add on lead can be soldered to the terminals. A lipo 1000 mah battery can be had for cheap at any hobby shop and plug into the lead. Easy charging and on the fly switchable. The batteries found in the model aircraft section are far more reliable than what comes with it. To mount said battery, I just use a strip of velcro.
It doesn't have image stabilizer but on a decent road I haven't had much issue. If it was on a helmet mount it would be perfectly smooth.