Maxell CR2032 3V Lithium Coin Cell Battery

The Maxell CR2032 is a 3V lithium coin cell, best known as the battery that keeps a motherboard's CMOS and BIOS settings alive while the PC is unplugged. The same cell also powers watches, calculators, key fobs, remotes and a long list of other small electronics. Chemistry is lithium manganese dioxide, rated at a nominal 3V with a capacity of 220 mAh, in the standard CR2032 format of 20.0mm across and 3.2mm thick, weighing around 3.0g. It holds a stable voltage under low-load discharge, resists leakage well and keeps its charge on the shelf for a long time. The operating range runs from -20°C to +85°C, which comfortably covers the inside of a warm case in a warm room. If a PC has started forgetting the date, resetting BIOS settings or complaining about the system clock at boot, this is the part to replace, and it is a quick job with the machine switched off and unplugged at the wall. It is also worth keeping a spare in the drawer for a car key fob, a bathroom scale or a wall thermometer, since these cells sit for long periods without going flat.