Although they don't have an extra cable for charging they still will provide energy to the attached device as the MHL cabling standard includes power transmission when the cable is paired between two MHL-enabled units.
Inkastoo aysan haysan cable dheeraad ah oo ku amraya in ay wali ku siin doonaa Tamarta si ay u qalab ku lifaaqan sida cabling heerka MHL ka mid ah gudbinta xoog markii cable la aadeen u dhexeeya laba cutub MHL-karti.