Simply Auto SB-CR1220 CR1220 3V Lithium Coin Cell Car Key BatteryThe Simply Auto CR1220 Battery is the smallest cell in the range by diameter, measuring just 12mm across. It is the one specified when a designer has run out of room entirely, and it is easy to underestimate how small that is until you have one in your hand. If your old cell looks noticeably smaller than the coin cells you are used to seeing, this is likely what you need.A CR1220 battery is 3 volts. It is a lithium manganese dioxide coin cell measuring 12mm across and 2mm thick with pressure contact terminals, and it is a direct drop-in for anything specified as CR1220, 5012LC, DL1220 or ECR1220. Lithium chemistry holds that 3V steady under load instead of tapering off gradually, so your remote keeps its range almost until the cell is spent, and an unopened battery keeps for up to 10 years in storage. It is CE, UKCA and RoHS compliant.Fitment is more straightforward with the CR1220 than with the larger cells, because nothing else in the range shares its 12mm diameter. There is no near-identical neighbour to confuse it with. Still worth reading the code on the face of the old battery before ordering, and worth noting the orientation before you lift it out, since a cell this small is easy to drop and easy to fit the wrong way up.Beyond car key fob battery replacement, the CR1220 also powers watches, calculators, organisers, glucometers, digital thermometers, toys, small remotes and other miniature electronics.If your key takes a different cell, the full Simply Auto car key battery range covers CR1616, CR1620, CR1632, CR2016, CR2025, CR2032, CR2430, CR2450 and the 23A, 27A and A76 alkalines.