It's supposed to charge your held item and other armor, but it doesn't seem to charge anything other than itself.
I thought it might be due to non-cooperation between mods, but it doesn't even charge the modular mining drill from the same mod.

Addendum: It seems to actually charge jetpacks from the Iron Jetpacks mod.

But it does not charge AE2 wireless terminals, or as previously mentioned the modular mining drill.
Doesn't seem to work for held items as advertised?