Battery Elimination/Replacement with USB or LED Power

thingiverse

USB or LED Powered Battery Replacement Works efficiently with USB Power Supplies as a replacement for 2 AA Cells. For more cells, add my AddOn Cell connected to the "+ out" on the PCB and switch from USB Power to a LED power supply (up to about 7 cells - 10.5 V). To control voltage, use a cheap step-down circuit: https://amzn.to/37Up4kY The voltage needs to be adjusted to about 1.5 V per battery cell using a small screw and multimeter as shown in one of my pictures. As the positive pole, trim the head to about 6 mm of a thumbtack. For the minus use a piece of brass fastener. This USB plug may work: https://amzn.to/3qQVQfl Connect the red cable to the "+" at the "in" side of the PCB and black to the "-". To power more than 2 cells, use this one: https://amzn.to/3gDQqzG Keep in mind that this power supply works with high voltage and install it only if you have the right knowledge for working with electrical power!