One more question:
One says that igrill is battery eater. WIFI will be more a battery eater.
I am thinking to use 2 pieces of A5 battery, and with an AC/DC socket.
I can also design a BUILT-IN recharge circuit for Li-ion battery.
Usually if you buy Li-ion battery, you also buy a charging adapter.
Do you pay for a built-in recharge circuit or not, extra cost is $5.