I always liked the idea of the Crystal Charger, but it is quite redundant now that it can simply charged in a MFE-transmitter. That however is mid-tech and finding diamonds everywhere is expensive early game. So I was thinking why not bring back the Crystal Charger that takes a full 32 EU per tick, but is able to charge 
, 
, 
, 
, lapatron crystal, and the lap-pack at slow rate, so that extremely cheap operations can be set up to slowly charge items without requiring any actual diamonds.
A crystal Dis-charger can be equally annoying to add.
Or have it do both in one go.