This Recommendation is applicable to the case of multiple power feeding configurations at the input of information and communication technology (ICT) equipment in ICT systems. It defines the requirements for the power inputs combination of the three power interfaces: A (?48 V)@ P or A3 (up to 400 Volt DC (VDC)) and A3ac (AC) that could potentially be used for each input. This Recommendation also provides details of the power structure within ICT equipment@ between ICT equipment interfaces@ and ICT equipment system loads that is inclusive of system power converters. The input power configurations are categorized to allow for a better understanding@ identification@ impacts@ and benefits of adopting each power feeding solution. The consequence on battery test function with the different dual power inputs combinations are indicated. Requirements are given for avoiding the potential risk of voltage backfeeding from one input to the other and for general isolation requirements