A battery harvesting device and methods are disclosed for powering a load with a plurality of standardised batteries of different battery chemistries, each of the standardised batteries having a battery output voltage lower than a nominal voltage. The harvester comprises a power bus for attachment to the load, at least one receptacle arranged into each of a plurality of clusters, each receptacle configured for receiving one of the standardised batteries, each cluster further comprising electronics comprising an input connected to the receptacle and an output connected to the power bus, and a DC-DC boost circuitry for raising a battery output voltage of a connected one of the standardised batteries, and a processor for controlling the electronics such that each of the outputs connected the power bus is maintained at the nominal voltage.