Being a little underwhelmed by BatteryFu, I uninstalled it from my old HTC Desire, which was choking on account of a lack of space. Following that, something unexpected transpired. I was left with no 3G Mobile Wireless Access (i.e. no Internet connection).
On close inspection, BatteryFu had left me with an APN Type setting of BatteryFu_Disabled.
I changed this back to default to solve the problem. But really, Battery_fu shame on you!