Systems and methods provide intelligent battery charging and balancing. Energy deficits can be forecasted based on historical data and forecasted energy generation. The deficits can be used to determine charging currents over a period of time, and battery cassettes can be charged according to the charging currents to compensate for the forecasted energy deficit. The states of charge of the battery cassettes can be periodically rebalanced. The battery cassettes can be coupled in series and charged and balanced while providing output to a load.