Rework of a Chinese sensor lamp powered by a single 18650 battery, or powered only by USB. To install more batteries, I removed the bottom cover and printed a new bottom, which freely accommodates a holder for several 18650 batteries. If the lamp is designed to be powered only by USB, you also need to install a module for charging lithium batteries combined with a DC-DC converter to 5 volts, which are needed to power the sensor board.