As an affordable option with a long 10-year shelf life, 9-volt batteries have been the battery of choice for smoke alarms for a long time. The life span of a 9V battery depends on the quality and ...

A 3D-printable 9V battery caddy compatible with Lego® Powered Up!® Hub 88009, so you can make your motorized Lego creations rechargeable instead of throwing away zillions of AAA batteries. This is not ...