From what i know it can not be changed.
And the Loss was disabled because the enet was still in construction in 1.6.4-1.7.x, it was not capable at the moment to handle loss.
Sadly (i dont know if that is the case anymore so correct me if i am wrong) the IC2 Team had implemented instant loss.
What that means before it was nessesary that you needed to reach natural numbers (1-2-3-4-5-6) to apply loss. So 1.2EU loss would be 1EU loss and 1.8EU loss would be 1EU loss, that is in +1.10.2 versions (could be later) completely removed. Loss gets applied instantly so the overal loss is in general a lot higher now since you lose everything instantly and not freshhold based.
EnergyLoss itself is not a bad concept, i fully agree on that feature and would be sad myself to lose it even in the EXP version.
But the current Exp Version implementation of it is just to punishing leaves no room for creativity in terms of how you could design with it.
But sorry no possebility. Unless they changed it.