Have a bug.
Electric engines run without need of IC-energy and acts like IC-source.
= BC wooden pipe
= small engine
Charge BatBox with RE-bat, activate engine with redstone. BatBox will start to charge from output (!) side.
SSP, MC 1.1, IC2 1.64, BC 2.2.12, RP 2.0 4d, Adv. machines 3.2b2, Crossover 1.18.
UPDATE: problem appears at the moment when redstone signal is off - engine sends EU back to circuit, and it sends back more than it takes. Example (activated by RedPower timer with 1s interval):
I tried it and could not get it to happen, I might be doing it wrong. but it did what it was suppose to for me. maybe another mod installed or only a certain version of buildcraft is doing it.