1. When there is no Sim Card inserted in the device:
It was lasting for about 4 hours when Wifi is On for around 2 and 1/2 hours. The usage includes web browsing when the Wifi is On and playing games when Wifi is Off. The tab was under continuous usage for the complete time. The brightness was around 30% (You will come to know why I am mentioning about the brightness)
2. When there is a 3G Sim Card inserted in the device:
The life got reduced, obviously, but I don't remember the exact figures of how long it lasted. But when data service is disabled and kept in standby it stands for days (i.e., you are using it as a phone only) and it is a good news. So I can say that the Sim Card as such won't drain much of the battery expect when data is being downloaded/uploaded through Wifi or 3G service.
3. Effect of Brightness of Screen:
The screen brightness plays a major role (bigger than Wifi) in determining the battery life. I once happened to be in a bright day light and increased the brightness to 100%. The visibility was not excellent at that level too, but the battery started "running down", literally. Within 30 minutes the battery was down (from some where around 90 to 80%, ofcourse I was using 3G data service during that time). From that time, my brightness is only 0% when I stay indoor (The visibility is good even at 0%, indoor).
4. Charging Time:
It takes 2 hours for the battery to charge from 0% (switched off due to low/no power) to 100%. This is reasonable I feel.
5. Performance from applications perspective:
When playing games the performance is better compared to the case when browsing through Wifi. And it varies from game to game, for e.g. Angry Birds sucks less battery while Fruit Ninja needs more (the battery drains approximately twice faster while playing Fruit Ninja). When using applications like pdf reader, the battery life is really good. So, if you are looking to use the Magiq Tab as a document reader, you won't be disappointed much with the battery.
Overall, the battery's performance is not good and it is the only thing I am disappointed with till now.