Carries babies, full of energy (5)
I believe the answer is:
totes
'carries' is the definition.
(toting is a kind of carrying)
'babies full of energy' is the wordplay.
'babies' becomes 'tots' (I've seen this before).
'full of' indicates putting letters inside.
'energy' becomes 'e' (physics symbol as in E=mc2).
'tots' going around 'e' is 'TOTES'.
(Other definitions for totes that I've seen before include "Carries, drags" , "Bears" , "Carries the betting system" , "Carries or shoulders" , "Carries, lugs" .)