Hi alec,
Some good ideas, better than i had and i'll explain.
First, yes, the current is max about 0.8 amps when booting up and about 0.6 amps when running normally, and about 60 microamps when shut down. I did not measure the current in sleep mode yet but maybe next time as it is easy to measure now with that one battery lead cut for the switch.
I think i have a small switch that will handle this, probably good enough for now, but yes i can look into the MOSFET solution too with an even smaller switch in the future.
As to the other thought, that's yes too, it does have a built in clock calendar and yes it requires battery power of course to keep alive. This is where the downside to disconnecting the battery comes into play. The real time clock shuts down and resets to August 2011 (i think it was 08/08/2011). That means on reconnect and power up the calendar and clock are way off. This would be a big problem if i had to use the tablet more often because i would not want all my files saved to be saved with a date of 08/08/2011 unless i first set the date each time. I'd have to turn on the switch, power up, then set the date then set the time to get around this.
So the battery disconnect for complete power down (and absolutely no self turn on ever) works very nice, except for the drawback that the date and time get reset so they are way off next time i power up. Perhaps i'll look into setting these via microcontroller in the future somehow, but right now it's not too much of a concern because i dont have to use the tablet that often.
The other upside now (or at least soon) is that i can connect any Li-ion battery to the tablet that i want to. I have several batteries around from other stuff i use (mostly flashlights) and any one of them would run the tablet. I have to connect one more wire to the board to get this functionality but that's not a big deal now.
One other thing i should mention is that my tablet came apart by snapping apart the bottom plastic case from the top plastic part of the case. I saw on YouTube that someone had taken theirs apart by pulling off the TOP display plastic (clear plastic). Doing it that way can be very hard, so i would have to recommend trying to get the bottom off instead. It could be very hard to get that top plastic and touch screen back together again perfectly.
The plastic case parts snap apart much like a modern hand calculator or IR remote control. There are little nubs that fit into little grooves inside the case near the edges of the plastic and that's what holds the two halves together.
The top clear plastic is glued on however, so that's not easy to get off, or back on.