Circuit Gem Battery Not Charging

[FrozenKaos]

I've finished putting together my Circuit Gem and everything is perfect, with the exception of one minor, but game-breaking issue - the battery will not charge while connected to the circuit gem. It runs fine while connected with a micro-usb cable. If also runs fine on a battery until discharged. But it will not charge back up. I thought it might be the battery, so I tested with a 2nd one (different size and mfg) and had the same issue. What could possible be causing this?

[kite]

Does the blue LED flash at all when plugged in? Did the battery ever get plugged in the wrong way round? Did you follow all the steps from the step by step guide successfully? (Specifically, the first 5 or so steps are all about power and battery charging to be done BEFORE soldering anything together)