Simply Auto SB-CR1620 CR1620 3V Lithium Coin Cell Car Key BatteryThe Simply Auto CR1620 Battery belongs to the smaller 16mm family rather than the common 20mm coin cells. That four millimetre difference in diameter is easy to miss by eye but impossible to work around: a 16mm cell dropped into a 20mm holder will not make proper contact, and a 20mm cell will not seat in a 16mm one at all. If your key takes a CR1620, only a CR1620 will do.A CR1620 battery is 3 volts. It is a lithium manganese dioxide coin cell measuring 16mm across and 2mm thick with pressure contact terminals, and it is a direct drop-in for anything specified as CR1620, 5009LC, DL1620 or ECR1620. 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.Checking fitment takes seconds and is worth doing properly with the 16mm cells. Read the code printed on the face of the old battery rather than judging by size, because the CR1620, CR1616 and CR1632 all share the same 16mm diameter and differ only in thickness. Note the orientation before you lift the old cell out and handle the new one by its edges to keep finger grease off the contacts.Beyond car key fob battery replacement, the CR1620 also powers watches, fitness trackers, car alarm remotes, glucometers, digital thermometers, calculators and other compact electronics where space is tight.If your key takes a different cell, the full Simply Auto car key battery range covers CR1616, CR1632, CR1220, CR2016, CR2025, CR2032, CR2430, CR2450 and the 23A, 27A and A76 alkalines.