This paper addresses the problem of precoder design in a MIMO broadcast scenario where the terminals are battery-powered devices provided with energy harvesting capabilities. Models for the power consumption of the RF and decoding stages are discussed and included in the design of the proposed scheme. Sum-rate maximization is taken as optimization policy and energy-related constraints are considered to increase the duration of the batteries and, thus, the network lifetime. Simulation results show that not only the usage of battery is improved when compared with other traditional allocation policies, but also the average data rate is enhanced.