Hey people. I am new to tablets and want to buy one Android-based. I have some general questions about power. I know that the answers depends on manufacturer, so I just ask for the most common/usual case. I) If it's usually/always possible to replace a battery in Android tablets or, in some devices, if a battery is dead then a tablet is dead? If possible, are these batteries usually 1) standard between different brands, so it's easy to find them and replace them yourself 2) different for different brands, but it's possible to buy them and replace them yourself 3) embedded in device and you have to give a tablet to manufacturer service center to replace a battery 4) something else? II) A similar question, is it usually possible to remove a battery and to work without it through AC Adapter directly? III) Another question, is it usually possible to work with a tablet when it has a proper battery, is connected via AC Adapter and is charging? I ask this because I once had a cheap digital device which couldn't be used during charging (which is terrible).