Among the challenges involved in the delivery of online content to anybody, anytime, and anywhere, one can note the limited battery power that mobile devices have. This paper presents a mechanism for saving battery power by adapting educational multimedia type content not only based on the learner profile but also based on device characteristics. In order to support this type of adaptation, metadata is added to the content and adaptation rules are defined using an authoring tool. Experimental tests have shown that significant mobile device battery power can be saved using the proposed content adaptation solution, whereas subjective tests conducted on a number of participants have shown that this can be done without significantly affecting the learning process.