The BT-M-SN-R-CR1220A is a specialized surface-mount coin cell holder designed specifically for CR1220A lithium batteries, which measure 12.0mm in diameter and 2.0mm in thickness. This battery holder is a member of the ANTENK BT series of coin cell retainers and provides a reliable, solderable interface between a PCB and a replaceable CR1220 coin cell battery . The model designation breaks down as follows: "BT" indicates Battery Holder, "M" likely refers to the mounting configuration or series, "SN" typically denotes surface mount with nickel or tin plating options, "R" signifies retainer or tape-and-reel packaging, and "CR1220A" specifies the compatible battery size. The holder is constructed with a high-temperature PPS (Polyphenylene Sulfide) or LCP (Liquid Crystal Polymer) insulator housing, rated UL94V-0 for flame retardancy, ensuring dimensional stability and heat resistance during reflow soldering processes . This holder is designed for surface-mount technology (SMT) assembly, allowing it to be placed and soldered onto PCBs using automated pick-and-place equipment, making it ideal for high-volume manufacturing environments .
The mechanical design of the BT-M-SN-R-CR1220A focuses on secure battery retention and reliable electrical connectivity. The holder features gold-plated phosphor bronze contacts that provide excellent conductivity, corrosion resistance, and durability . Phosphor bronze (C5191) is the specified contact base material, offering good spring properties and fatigue resistance essential for maintaining consistent contact pressure over the battery's service life . The gold plating on the contact surfaces ensures low contact resistance and prevents oxidation, which is critical for maintaining stable electrical performance in applications where the battery may remain in place for extended periods. The holder is designed for top-entry battery insertion, allowing the CR1220A coin cell to be easily snapped into place and retained by spring tension from the contacts . This open-frame holder design facilitates quick battery replacement without requiring special tools. The above-board height is typically in the range of 4.0mm to 5.4mm, providing a low-profile solution for space-constrained PCB layouts . The holder is packaged in tape-and-reel format, with specifications including a 32mm-wide carrier tape conforming to ANSI/EIA-481 standards and a 330.2mm diameter reel that typically holds 500 units per reel .
The BT-M-SN-R-CR1220A delivers robust electrical performance suitable for a wide range of low-power applications. Key electrical characteristics include a contact resistance of 30mΩ maximum, ensuring minimal voltage drop across the battery-to-PCB interface . The insulation resistance is rated at 1000MΩ minimum, providing excellent isolation between the battery terminals and preventing leakage currents that could drain the battery prematurely . The dielectric withstand voltage is specified at 500V AC for one second, demonstrating adequate insulation integrity for most low-voltage applications . The operating temperature range spans from -30°C to +70°C, or in some compatible variants from -40°C to +85°C, allowing deployment in consumer electronics, industrial equipment, and automotive applications within standard environmental limits . The holder is rated for use with 3V CR1220 lithium coin cells, which typically provide a nominal capacity of approximately 35-40mAh, making this holder suitable for low-current backup power applications, real-time clock (RTC) power sources, and memory retention circuits.
The BT-M-SN-R-CR1220A coin cell holder is widely deployed in applications requiring reliable, field-replaceable backup power or primary power for low-current devices. Primary application areas include real-time clock (RTC) backup circuits on computer motherboards and industrial control systems, IoT sensors and wireless devices, medical equipment such as portable diagnostic devices and patient monitors, wearable electronics, memory retention circuits for PLCs and embedded systems, and compact consumer electronics . The surface-mount design allows for automated assembly, reducing manufacturing costs while ensuring consistent placement accuracy. The gold-plated phosphor bronze contacts provide long-term reliability, maintaining low contact resistance even in environments subject to vibration or temperature cycling . Major manufacturers producing compatible CR1220 surface-mount coin cell holders include Harwin (S8411-45R series), Keystone Electronics (2894 Vibra-Fit series), MPD (BC501SM), and RS PRO, with the ANTENK BT-M-SN-R-CR1220A offering a competitive alternative in this product family . In summary, the BT-M-SN-R-CR1220A is a robust, space-efficient, and manufacturable coin cell holder that combines reliable electrical performance with secure battery retention, making it an ideal choice for PCB designs requiring a replaceable CR1220A battery for backup power or primary low-current applications.
