Why AG and CR Cross-Compatibility Matters for OEM Product Design

OEM product design engineers frequently face a button cell selection question that the marketing literature does not answer directly: can an AG-series alkaline button cell be used in a battery compartment designed for a CR-series lithium button cell, or vice versa? The question arises because both families share the same general coin form factor and both are documented in cross-reference guides for the broader LR/L, SR, AG, and CR families covered by industry resources such as the cross-reference table at ic-components.com.

The short answer is no. The AG and CR families operate at different nominal voltages (1.5V for AG alkaline, 3V for CR lithium manganese dioxide), use different chemistries, and follow different cross-reference mappings to the IEC LR and CR designations. The IEC 60086-3 standard documented at unikeyic.com establishes the button cell naming convention that distinguishes the CR lithium chemistry from the LR alkaline chemistry at the IEC designation level. Physical dimension overlap is coincidental rather than functional, and an OEM design that lists both AG and CR as interchangeable parts in the bill of materials will produce a product that fails the application requirement once the wrong cell is loaded.

Our button battery product line covers both families. The AG-series alkaline cells are documented in the alkaline button cell section of the product family, and the CR-series lithium cells are documented in the Li-MnO2 button cell section. This article maps the cross-compatibility question at the dimension, voltage, and capacity level so that OEM engineering teams can specify the correct cell chemistry without ambiguity in the bill of materials.

Voltage Mismatch: The Primary Cross-Compatibility Barrier

The AG and CR families differ at the voltage level in a way that no cross-reference chart can resolve. AG-series alkaline button cells operate at a 1.5V nominal voltage, which matches the LR IEC designation. CR-series lithium manganese dioxide button cells operate at a 3V nominal voltage, which matches the CR IEC designation. Per the watch battery cross-reference resources such as watchbattery.co.uk, lithium watch batteries and button cells operate at 3 volts and cannot be substituted for a 1.5 volt silver oxide watch battery or alkaline watch battery, even if the sizes are comparable.

The voltage mismatch means an AG cell cannot serve as a drop-in replacement for a CR cell in a 3V application, and a CR cell cannot serve as a drop-in replacement for an AG cell in a 1.5V application without risking damage to the load circuit. Per the general button cell documentation at Wikipedia, use of a cell of the right voltage but unsuitable characteristics can lead to short battery life or failure to operate equipment, which reinforces the OEM design principle of specifying a single cell chemistry and voltage class. The cross-reference work should be limited to within the chemistry family (AG to LR within the alkaline family, CR to BR within the lithium family) rather than across chemistry families.

For OEM designs that need a 3V supply, the CR2032, CR2025, CR2016, CR2430, and CR2450 are the typical choices within the CR series. For OEM designs that need a 1.5V supply, the AG1 through AG13 family maps to the LR IEC designations per the cross-reference table at ic-components.com, with capacity ranging from below 30mAh for the smallest cells up to approximately 165mAh for the AG13/LR44.

Dimension Overlap: Physical Form Factor Comparison

AG and CR cells share the same general coin form factor, but their dimension codes do not match across the two families. The AG-series uses a code that maps to the LR IEC series. Per the cross-reference table at ic-components.com, AG1 corresponds to LR621, AG3 to LR41, AG4 to LR626, AG5 to LR754, AG10 to LR1130, AG12 to LR43, and AG13 to LR44.

Within our product line, the AG13 cell is documented as 11.6mm diameter by 5.4mm thickness with 165mAh capacity and 1.5V nominal voltage, suitable for lavalier microphone and similar small-form-factor applications. The CR-series cells follow a different dimension coding scheme where the first two digits indicate the diameter in millimeters and the last two digits indicate the thickness in tenths of a millimeter. The CR2032 is therefore 20mm diameter by 3.2mm thickness, the CR2025 is 20mm diameter by 2.5mm thickness, the CR2450 is 24.5mm diameter by 5.0mm thickness, and the CR2016 is 20mm diameter by 1.6mm thickness.

There is no AG-series cell that matches the CR2032 footprint of 20mm by 3.2mm, and there is no CR-series cell that matches the AG13 footprint of 11.6mm by 5.4mm. The two families occupy different points in the coin cell dimension grid, and OEM designs that select a cell from one family cannot list a cell from the other family as an alternative without changing the battery compartment design.

Capacity Profile Comparison Across AG and CR Families

The capacity profile differs across the AG and CR families because the lithium manganese dioxide chemistry has higher specific energy than the alkaline chemistry at similar form factors. AG-series capacities typically range from below 30mAh for the smallest AG0 and AG1 cells up to approximately 165mAh for the AG13/LR44 cell. CR-series capacities range from approximately 25mAh for the CR1220 up to approximately 600mAh for the CR2450 cell.

Within our product line, the CR2032 is documented at 210mAh capacity with 20mm by 3.2mm dimension and 3V nominal voltage, while the CR2025 is documented at 150mAh capacity with 20mm by 2.5mm dimension and 3V nominal voltage. The CR2450 reaches 600mAh capacity with 24.5mm by 5.0mm dimension and 3V nominal voltage, which positions the CR2450 as the highest-capacity cell in the CR family that we produce. The CR2430 sits between the CR2032 and the CR2450 in capacity and dimension.

For an OEM design that requires higher capacity in the 3V class, the CR2450 is the typical selection. For a design that requires lower profile in the 3V class, the CR2016 or CR2025 is the typical selection. For a design that requires 1.5V with mid-range capacity, the AG13/LR44 is the typical selection. The selection logic flows from the voltage requirement and the battery compartment dimension rather than from cross-family substitution.

Cross-Reference Mapping for the AG and LR Families

The AG-series alkaline button cells map to the LR IEC designations through a documented cross-reference table. Per the cross-reference guide at ic-components.com, AG1 corresponds to LR621, AG3 to LR41, AG4 to LR626, AG5 to LR754, AG10 to LR1130, AG12 to LR43, and AG13 to LR44. These AG-to-LR mappings are within the same alkaline chemistry family and can serve as substitutes in 1.5V applications where the dimension matches the battery compartment.

The same cross-reference table documents additional mappings for AG2, AG6, AG7, AG8, AG9, and AG11 to specific LR designations. The mappings preserve the 1.5V nominal voltage and the alkaline chemistry across the AG and LR naming systems, which means an OEM design that uses an AG cell can typically list the corresponding LR cell as a substitute without changing the application requirement.

For the AG13 cell that we produce with 11.6mm by 5.4mm dimension and 165mAh capacity at 1.5V, the LR44 cross-reference matches the same dimension and voltage profile. The cross-reference is documented across the broader industry reference guides and can be used to align the bill of materials naming with the IEC LR designation without changing the cell specification.

CR-Series Lithium Cell Family Overview for OEM Selection

The CR-series lithium manganese dioxide button cells span a dimension grid from the smallest CR1220 at 12.5mm by 2.0mm through the larger CR2450 at 24.5mm by 5.0mm. Per the OEM application check list documented in the Varta Primary Lithium Cells Handbook, the CR button cell selection should consider the nominal and operating voltage, the load current and profile, the duty cycle, the temperature requirements, and the shelf life of the application.

Our CR-series product line covers CR2016, CR2025, CR2032, CR2430, and CR2450 in the Li-MnO2 chemistry family. The CR2032 Li-MnO2 button cell is documented at 20mm by 3.2mm with 210mAh capacity and 3V nominal voltage. The CR2450 reaches 600mAh at 24.5mm by 5.0mm and is documented in our Li-MnO2 button cell range for applications that require higher capacity within the CR-series form factor.

For OEM designs that need to align with industry standards documentation, the Varta Primary Lithium Cells Handbook provides a comprehensive OEM application check list that covers the project information, marketing data, technical requirements, and feasibility stages of cell selection. The handbook is a useful reference for OEM engineering teams that need to align the bill of materials naming with the IEC CR designations and document the selection rationale.

Selection Logic for OEM Engineering Teams

The OEM cell selection logic should follow three steps in sequence. First, confirm the voltage requirement of the application circuit. Second, confirm the battery compartment dimension from the mechanical design. Third, select the cell chemistry and capacity that match the voltage requirement and the dimension.

For a 3V application with a 20mm by 3.2mm battery compartment, the CR2032 is the selection. For a 3V application with a 20mm by 2.5mm battery compartment, the CR2025 is the selection. For a 3V application with a 24.5mm by 5.0mm battery compartment, the CR2450 is the selection. For a 1.5V application with an 11.6mm by 5.4mm battery compartment, the AG13/LR44 is the selection. The selection rationale for the AG13/LR44 cross-reference is documented in the unikeyic.com button cell compatibility guide, which maps the LR44 chemistry and dimension to the AG13 cross-reference under the IEC LR designation.

The selection should not cross the chemistry boundary. An OEM design that lists CR2032 as the primary cell should not list AG13 as a substitute because the voltage mismatch will damage the load circuit. An OEM design that lists AG13 as the primary cell should not list CR2032 as a substitute because the voltage mismatch will under-drive the load circuit.

Common OEM Design Mistakes in Button Cell Selection

Three mistakes recur in OEM button cell selection that the AG and CR cross-reference work should resolve. The first mistake is listing CR and AG cells as interchangeable substitutes in the bill of materials, which causes field failures when the wrong cell is loaded during assembly. The second mistake is specifying the AG code as the primary cell reference while the IEC LR code is documented as the cross-reference, which causes sourcing confusion when the procurement team queries the supplier catalog.

The third mistake is selecting a cell from one chemistry family based on dimension overlap without verifying that the dimension actually matches the battery compartment. For example, an OEM design that uses the CR2032 form factor should not list the CR2450 as a substitute even though both are CR-family cells, because the CR2450 is 24.5mm diameter versus the 20mm diameter of the CR2032. The dimension check should be done at the millimeter level rather than at the chemistry family level.

Our engineering team reviews the OEM specification sheet during the RFQ stage to confirm the cell chemistry, dimension, voltage, and capacity match the application requirement. The cross-reference check is part of the standard RFQ review to prevent the three mistakes above from progressing into the production bill of materials.

Frequently Asked Questions

Can AG series alkaline button cells be substituted for CR series lithium button cells in an OEM design?

No. AG series alkaline button cells operate at 1.5V nominal while CR series lithium button cells operate at 3V nominal. The voltage mismatch means an AG cell cannot be a drop-in replacement for a CR cell, and vice versa, regardless of physical dimension similarity. Engineers designing an OEM product that uses a CR2032, CR2025, CR2016, CR2430, or CR2450 should specify the CR chemistry in the bill of materials and should not list an AG-series alternative as a substitute without an explicit voltage step-down circuit.

What is the AG and CR nomenclature origin for button cells?

AG is an alkaline button cell designation that overlaps with the IEC LR series. AG1 corresponds to LR621, AG3 to LR41, AG4 to LR626, AG5 to LR754, AG10 to LR1130, AG12 to LR43, and AG13 to LR44 per the cross-reference table documented at ic-components.com. CR is the IEC designation for lithium manganese dioxide button cells with a 3V nominal voltage. The two naming systems are not directly substitutable because the chemistry, voltage, and capacity profile differ.

Which button cell chemistry should an OEM specify for a low-drain long-shelf-life application?

For low-drain applications where the device draws microampere-level current continuously and the design priority is shelf life and stable voltage over years of standby, CR lithium chemistry is the more common choice because of its 3V nominal voltage, low self-discharge rate around 1% per year, and a typical shelf life that extends to approximately 10 years under proper storage. Examples include CMOS memory backup on motherboards, real-time clock retention, and remote control transmitters.

Why do AG alkaline button cells and CR lithium button cells share some physical dimensions but not others?

AG alkaline and CR lithium button cells share the same general coin form factor but their dimension codes do not match across the two families. AG13 is an 11.6mm diameter by 5.4mm thickness cell with 165mAh capacity and 1.5V nominal voltage, while CR2032 is a 20mm diameter by 3.2mm thickness cell with 210mAh capacity and 3V nominal voltage. There is no AG-series cell that matches the CR2032 footprint, and there is no CR-series cell that matches the AG13 footprint.

What is the typical capacity range across AG and CR button cells for OEM selection?

AG series capacities typically range from below 30mAh for the smallest AG0/AG1 cells up to approximately 165mAh for the AG13/LR44 cell. CR series capacities range from approximately 25mAh for the CR1220 up to approximately 600mAh for the CR2450 cell. CR cells consistently deliver higher capacity than AG cells of comparable diameter because the lithium manganese dioxide chemistry has higher specific energy than the alkaline chemistry at the same form factor.

How does Ningbo Zhongsheng support OEM button cell selection across both AG and CR families?

Ningbo Zhongsheng Electronic Technology produces both the AG alkaline button cell family and the CR lithium manganese dioxide button cell family in our button battery product line, with capacity, dimension, and voltage documented per part number. Our engineering team reviews the OEM specification sheet against the AG and CR configuration options during the RFQ stage and confirms the cross-reference compatibility with the IEC LR and CR designations.

Procurement Action Steps for OEM Engineering Teams

OEM engineering teams specifying button cells for new product designs should follow a five-step review. First, confirm the voltage requirement of the application circuit and document the voltage class (1.5V or 3V). Second, confirm the battery compartment dimension from the mechanical design at the millimeter level. Third, identify the cell chemistry family that matches the voltage requirement (AG/LR for 1.5V, CR for 3V). Fourth, select the specific cell part number from the chemistry family that matches the dimension. Fifth, request the engineering specification from our team during the RFQ stage and confirm the cross-reference compatibility before releasing the bill of materials to production.

External references consulted for this article include the ic-components.com LR/L, SR, AG, CR/BR cross-reference table for the AG to LR mapping and the CR series parameters, the watchbattery.co.uk cross-reference table for the chemistry and voltage mismatch documentation between lithium and alkaline button cells, the Varta Primary Lithium Cells Handbook for the OEM application check list and selection criteria for CR-series cells, and the Tiger Head Battery button cell types and applications guide for the broader button cell chemistry classification and the LR versus CR voltage specification.