Extendable jumper cables for transferring electrical energy from a charged battery to a discharged battery include a first short cable having two clamp ends that detachably connect to two terminals of the charged battery, and a plug end that detachably connects to a cooperating plug end of a second short cable. The second short cable includes two clamp ends that detachably connect to two terminals of the discharged battery. The plug end and the cooperating plug end include cable connection fittings that allow the first short cable and the second short cable to be connected together to form a typical set of jumper cables. The plug end and the cooperating plug end further include respective plugs that cooperate to receive corresponding plugs of an extension cord to increase a length of the extendable jumper cables to electrically connect the charged battery and the discharged battery together when a distance separating the charged battery and the discharged battery is greater than a combined length of the first short cable and the second short cable.