We're planning to use a set with Overo Fire (Tobi board) and some sensors working with batteries for a long while, maybe a week, until recharge/exchange the batteries ( i dont know yet). We have here some Lithium Polymer batteries like this http://www.sparkfun.com/commerce/product_info.php?products_id=8483, i haven't tested it yet, but i think i will work just for some minutes. Does anybody have an idea of how can i keep the Overo on for such a long time?
And another question, may i connect the battery in the V_Batt_5 (pin 40) and GND (pin 1) of the Tobi right? Even if my batt provides only 3.7 V? What is for the VCC_3.3 (pin 2)?