POWER SOURCE

There is provided a power source (100) for electrical devices. The power source (100) provides a cell management system for an electronic device and has the following features: at least two individual cells (102, 104); at least two controllers (112, 114) operationally connected on a one to one basis to the at least two individual cells (102, 104) and configured to measure the remaining charge of the at least two individual cells; wherein: the power source further comprises a system controller (125) operationally coupled to the at least two controllers (112, 114) and configured to direct the operations of the at least two individual controllers in controlling power provided by the at least two individual cells to a load; and the system controller (125) controls power provided by the at least two individual cells (102, 104) to the load so that the discharging power of each cell corresponds to its respective fraction of its total remaining capacity.