Found in the new Direwolf20 pack and validated with just Forge 2124 on MC-10.2 with versions 10.2-R70 and 10.2-R75.

Whenever energy lasers are used to transfer power, consumer devices (Canola Press, Grinder) never completely fill with RF. They will only charge to MaxRF-1, which causes a continuous power draw from the generator (tested with Oil and Coal) which will rather quickly consume all fuel and stored power from the generator.

I know you intended there to be some loss, but it didn't sound like it would be a vampire system. Is constant power draw with no work being done intentional?