batt boxes and such power in limits?

I recall battboxes and MFSU's had a limit on power going in.. IE so much EU/t can come in.

None of the boxes have any tooltip to show they have a limit IN.. just out!

So the question is, is the a error? do they have limits still or will there not be a need for transformers in the future?

good.. i was not sure and felt it was going to be headache inducing..