Batteries Selection Guide
Batteries are divided by IEC code into sizes such as AA, AAA, C, D and 9 V, and into chemistries such as zinc-carbon and alkaline; choose the size and chemistry the device requires.
This guide covers what to look at when choosing products in the Batteries category.
Battery sizes and IEC codes
On device labels and in user manuals, the battery is most often written by its IEC code; the code shows both the size and the chemistry.
- AA (pencil). 14.5 × 50.5 mm. Alkaline carries the code LR6, zinc-carbon R6, NiMH HR6: AA batteries.
- AAA (slim pencil). 10.5 × 44.5 mm. Alkaline LR03, zinc-carbon R03, NiMH HR03: AAA batteries.
- C (medium) and D (large). Alkaline C battery LR14, alkaline D battery LR20; their NiMH equivalents carry the codes HR14 and HR20. The alkaline D battery is under large D batteries; the C size is listed only among rechargeable batteries.
- 9 V. Alkaline 6LR61, zinc-carbon 6F22, NiMH 6HR61: 9V batteries.
- 12 V cylindrical. A23 (10.3 × 28.5 mm) and A27 (8.0 × 28.2 mm) remote control batteries are under specialty batteries. The two have the same voltage but different diameters; use the type the device requires.
Battery types by chemistry
- Zinc-carbon. Appears in product names as Manganese (Superlife). It is for devices that draw little current or run intermittently, such as wall clocks and remote controls; it falls short in devices that draw high current.
- Alkaline. At the same voltage it offers a higher energy density and a longer shelf life than zinc-carbon. Its capacity depends on the load: an AA battery that can reach 3000 mAh at low current can fall to as little as 700 mAh at a 1 A load.
- NiMH. A rechargeable chemistry; unlike an alkaline battery, it does not lose its capacity at high current. Standard NiMH batteries self-discharge while idle. Varta states that the Recharge Accu Power series in this category comes pre-charged and retains up to 75% of its capacity after 12 months.
How to read a button cell code
In the code of button cell batteries, the letters give the chemistry and the digits the size. CR means lithium manganese dioxide (3 V), SR silver oxide (1.55 V), and LR alkaline (1.5 V). The last two digits give the height in tenths of a millimeter, and the leading digits give the diameter in millimeters (rounded down).
- CR2032: 20 mm diameter, 3.2 mm height.
- CR2025 and CR2016: same diameter, 2.5 mm and 1.6 mm height.
- CR2430 and CR2450: 24.5 mm diameter, 3.0 mm and 5.0 mm height.
The voltage of a silver oxide battery stays largely stable until the end of its life; an alkaline button cell of the same size has lower capacity and voltage stability. Manufacturers use different names for alkaline button cells; the product names give equivalent codes together (for example V12GA, LR43 and 186).
Rechargeable batteries and chargers
Rechargeable batteries are listed as NiMH in AA, AAA, C, D and 9 V sizes; there are different capacity options in the same size (2100 mAh and 2600 mAh for AA). The rated voltage of NiMH batteries in the 9 V size can be 7.2 V, 8.4 V or 9.6 V depending on the number of internal cells; check the value required for your device from the manufacturer data.
Battery chargers are selected to suit the chemistry and size of the battery. Single-use batteries are not designed to be recharged; attempting to charge a standard alkaline battery can cause it to split.
Brand and ordering notes
- The products in this category are of the Varta brand.
- For pencil and slim pencil batteries, the product name includes the pack information of 2, 4 or 10; check the order quantity accordingly.
- According to Varta's usage information, old and new batteries and batteries of different types are not mixed in the same device, and the batteries in a device are replaced together; determine the quantity by the number of battery slots in the device.
- Devices that measure battery condition are in the cell and battery testers category.
Comparison and selection table
| Selection Criterion | Alkaline Primary Battery (AA / AAA / 9V) | Lithium Coin / PLC Backup Battery (CR2032 / 3.6V) | Rechargeable Cells (Ni-MH / Li-ion) & VRLA Battery |
|---|---|---|---|
| Voltage & Chemistry | 1.5 V (AA, AAA, C, D) or 9 V (6LR61) alkaline | 3 V Lithium coin (CR2032, CR2025) or 3.6 V Li-SOCl2 | 1.2 V Ni-MH, 3.7 V Li-ion (18650) or 6 V / 12 V sealed lead-acid |
| Discharge Profile | Non-rechargeable, long shelf life, steady drain | Ultra-low self-discharge, 5–10 year memory retention | High cycle life, rechargeable hundreds of times |
| Typical Equipment | Multimeters, testers, flashlights, wireless transmitters | PLC/CNC memory backup, RTC clocks, encoders, key fobs | Emergency lighting, UPS, fire/burglar alarms, cordless tools |
| Key Sizing Check | IEC size code (LR6=AA, LR03=AAA) & pack quantity | Exact diameter × height (2032 = 20×3.2 mm) or wire connector | Match charger chemistry, voltage and capacity (mAh / Ah) |
Frequently asked questions
Can CR2025 or CR2016 be used instead of CR2032?
All three are 3 V lithium batteries with a diameter of 20 mm; the difference is in thickness: CR2032 is 3.2 mm, CR2025 2.5 mm, CR2016 1.6 mm. Because the battery compartment and contact spring are designed for a particular thickness, a thinner battery may not make contact in the compartment and a thicker battery may not fit; their capacities are also different. Use the code written on the device or on the battery that came out.
Does a 1.2 V rechargeable battery work in a device that uses 1.5 V batteries?
It works in most devices. A NiMH battery gives 1.2 V and a new alkaline battery 1.5 V; however, because the voltage of an alkaline battery falls during use, devices designed for these batteries generally operate down to around 1.0 V per cell. Varta also states that a NiMH battery of the same size can be used in most devices that use alkaline batteries. Battery gauges calibrated for alkaline batteries may show the charge level incorrectly with a NiMH battery.
Can an alkaline battery be recharged?
No. Varta states that single-use batteries are not designed to be recharged and that charging them significantly increases the risk of leakage and safety hazards. For use that will be recharged, NiMH rechargeable batteries and a charger suited to this chemistry are chosen. NiMH chargers are not designed to charge alkaline, zinc-carbon or lithium button cells.
What is the difference between a manganese (zinc-carbon) battery and an alkaline battery?
Both give 1.5 V and are made in the same sizes. The Varta Superlife batteries that appear as Manganese in product names are of zinc-carbon chemistry. An alkaline battery has a higher energy density and a longer shelf life; in continuous or high-current use it can last up to eight times as long as a zinc-carbon battery. A zinc-carbon battery is for devices that draw little current or run intermittently, such as remote controls and wall clocks.
Can A23 and A27 batteries be used in place of each other?
Both are 12 V alkaline batteries, but their dimensions differ: A23 is 10.3 mm in diameter and 28.5 mm long, A27 is 8.0 mm in diameter and 28.2 mm long. Because the battery compartment is made for a particular diameter, the type written on the device or on the battery that came out must be used.
Can an alkaline button cell be fitted in place of a silver oxide button cell?
Button cells of the same size with different chemistries fit each other's compartments mechanically, but they behave differently. A silver oxide battery gives 1.55 V, and its voltage stays largely stable until the end of its life. An alkaline button cell is 1.5 V; its capacity and voltage stability are lower. In voltage-sensitive devices such as watches and measuring instruments, the chemistry specified by the manufacturer is used.