The IC2 Power Supplier gives the EU Stargate Power Unit (from SG Craft) energy when its already at maximum capacity (1millionEU).
This only happens when I give it energy from logistics pipes and from ic2 at the same time (but ic2 stops giving energy once its at 1million EU).
It does not happen when I give it energy only with LP, IC2 or Gregtech.

I tested this in singpleplayer with the Infitech2 modpack v3.1.4
industrialcraft-2-2.2.748-experimental
logisticspipes-0.9.1.15
SGCraft-1.9.3-mc1.7.10

I think I have the same issue on FTB infinity Evolved Skyblock LP version is; 0.9.3.114

It seems like the Logistics EU power provider accepts packets even when it might not have space for the full packet. I have a reactor providing 420eu/t to an mfsu which is connected to the logistics EU power provider. This is hooked up to a basic logistics pipe with a power transportation upgrade, through some golden transport pipes to a logistics chassis mk 2 under an Ore Washing plant (16 eu/t when running with no overclockers). The chassis has an ic2 lv power supplier upgrade. This simple setup should not drain the MFSU, but it does, rather quickly.

I've also reproduced this in a test world, screenshot below. The quantum generator on the EU provider is producing 420eu/t but the mfsu is draining from the ore washing plant's 16eu/t draw. Just to note, both the MFSU and the logistics EU provider were full when I started the test.