This patent discloses designs of a controller for a solar powered LED lamp system. The control unit includes a controller that has a switching network and that selectively charges a battery from a solar panel, and selectively discharges the battery to power a lamp. The lamp itself includes a second part of the control unit that prevents over-charge and under-charge conditions of the battery. This may be accomplished using a low power passive network of LEDs and resistors, leaving the controller itself to only perform switching. Thus, the power consumed by the controller, and by the LED lamp system as a whole, may be significantly reduced.