My friend's nano axe does not "recognize" the battery (a lipo 350 mAH, 3.7v, 1.3Wh).
He bought it off tower hobbies, which sent him a reposition battery 100% free (to Brazil, mind you! great service).
However followed, (our understanding of) his instructions did not solve the glitch. Here is Lennie's answer - any hints to a noob?
If the battery/charger are OK, try turning on the transmitter and connecting the battery to the model. There is a small button on the back of the board on the right side of the model. Press and hold the button for about 5 seconds to see if linking the board and transmitter will correct the problem.
Great Planes Model Distributors