1/2 AA Battery vs. 14250 Battery

1/2 AA and 14250 batteries are compact cylindrical cells widely used in electronic meters, security systems, medical devices, baby monitors, pet collars, and small EDC flashlights.

Although the terms 1/2 AA and 14250 are often used interchangeably due to their nearly identical dimensions, they may differ in battery chemistry, which can affect performance, capacity, and discharge characteristics.

Features and Specifications

The 1/2 AA and 14250 batteries share nearly identical dimensions, typically measuring 14.0 mm in diameter and 25.0 mm in height, with a maximum diameter tolerance up to 14.5 mm. Some variants may reach 25.4 mm (1 inch) in height, but minor differences in height are generally less critical than variations in diameter when fitting battery compartments.

Common designations for these small cylindrical lithium batteries include 1/2 AA, 14250, CR14250, and ER14250. While certain labels are often associated with specific chemistries, this is not always consistent.

Therefore, when purchasing 1/2 AA or 14250 batteries, it's important to check not only the label but also the nominal voltage, capacity, and battery chemistry to ensure compatibility with your device.

Non-Rechargeable 1/2 AA and 14250 Batteries

Non-rechargeable 1/2 AA and 14250 batteries are commonly available in two primary chemistries:

LiMnO₂ (Lithium Manganese Dioxide):

These batteries use manganese dioxide (MnO₂) as the cathode material and typically deliver a nominal voltage of 3.0V with a capacity ranging from 900 to 1000 mAh, depending on factors such as cutoff voltage, load current, and ambient temperature. They are often marked with the prefix “CR,” such as “CR14250” or “CR 1/2 AA.” LiMnO₂ batteries are known for their stable output voltage, long shelf life of up to 10 years, and broad operating temperature range (typically -20°C to 70°C / -4°F to 158°F). Common applications include use as CMOS or motherboard batteries and in various industrial electronics.

Li-SOCl₂ (Lithium Thionyl Chloride):

Utilizing thionyl chloride (SOCl₂) as the cathode, these batteries provide a higher nominal voltage of 3.6V and a typical capacity of approximately 1200 mAh. They are recognized for their superior energy density, extended shelf life (10+ years), and exceptionally wide operating temperature range (some models function between -55°C and +85°C / -67°F to +185°F). These characteristics make them ideal for low-drain applications and environments with extreme temperatures. Li-SOCl₂ batteries in the 14.0 x 25.0 mm size are usually labeled as “ER14250” or “ER 1/2 AA.”

While LiMnO₂ batteries are still widely used, Li-SOCl₂ batteries are increasingly preferred for applications requiring enhanced performance under demanding conditions.

Note:

Many modern devices using 14.0 x 25.0 mm batteries are designed to accommodate both 3.0V and 3.6V variants, with 3.6V gradually becoming the standard. However, CR 1/2 AA (3.0V) batteries remain widely used due to their reliability and safety.

If your device is originally powered by a 3.0V 1/2 AA battery and no specific voltage tolerance is indicated, do not substitute it with a 3.6V battery. While the 0.6V difference may seem minor, it can lead to malfunctions or even permanent damage, especially in sensitive electronic equipment. Always follow the manufacturer's voltage specifications when replacing batteries.

Rechargeable 1/2 AA and 14250 Batteries

Rechargeable 14.0 x 25.0 mm batteries primarily use lithium-ion chemistries, with nominal voltages ranging from 3.2 to 3.7 volts depending on the specific type:

· IMR 14250: Lithium Manganese Oxide (LiMn₂O₄) chemistry, nominal voltage 3.6–3.7 V.

· INR 14250: Lithium Nickel Manganese Cobalt Oxide (LiNiMnCoO₂) chemistry, nominal voltage 3.6–3.7 V.

· IFR 14250: Lithium Iron Phosphate (LiFePO₄) chemistry, nominal voltage 3.2–3.3 V.

· ICR 14250: Lithium Cobalt Oxide (LiCoO₂) chemistry, nominal voltage 3.6–3.7 V. ICR batteries often offer higher capacities but typically have lower maximum discharge currents, which generally suits typical 14250 battery applications.

While other chemistries exist, these four are the most common, with ICR 14250 batteries being the most widely used.

Rechargeable 14250 batteries typically provide a nominal capacity between 280 and 350 mAh, though actual capacity varies with discharge current.

Compared to non-rechargeable CR 1/2 AA and ER14250 batteries, rechargeable 14250 cells have a higher self-discharge rate. However, they can be recharged over 500 times, offering significant cost savings in suitable applications.

Safety Note: Lithium-ion batteries must be charged only with chargers specifically designed for their chemistry. Improper charging can cause overheating, fire, or even explosion.

1/2 AA (14250) Battery vs. AA (14500) Battery

The 1/2 AA (14250) battery has a nominal size of 14.0 x 25.0 mm, whereas standard AA batteries measure approximately 14.5 x 50.5 mm, and rechargeable 14500 batteries are about 14.0 x 53.0 mm.

In short, 1/2 AA (14250) batteries share a similar diameter (~14 mm) with AA and 14500 batteries but are roughly half their height.

While theoretically, two 1/2 AA (14250) batteries placed in series could match the length of a single AA/14500 battery, the voltage difference is critical:

· Two 1/2 AA (14250) batteries in series produce 6.0 to 7.2 volts.

· A single AA battery typically delivers around 1.5 volts (range 1.2–1.8 V).

· A single 14500 lithium-ion battery delivers 3.2 to 3.7 volts.

This significant voltage discrepancy can easily damage electronic devices. Therefore, never replace a single AA or 14500 battery with two 1/2 AA (14250) batteries in series.

1/2 AA/14250 Battery vs. 4SR44/4LR44 Battery

The 4LR44 and 4SR44 batteries have nominal dimensions of approximately 13 x 25.2 mm. Their labels (4LR44 or 4SR44) indicate their internal structure—each consists of four LR44 or SR44 button cells stacked vertically.

The 4LR44 battery provides a nominal voltage of 6.0 volts, while the 4SR44 battery delivers around 6.2 volts.

Since the 1/2 AA/14250 battery (14.0 x 25.0 mm) and the 4SR44/4LR44 batteries (13 x 25.2 mm) have very similar sizes, it may seem possible to interchange them. However, because of the significant voltage difference, substituting a 1/2 AA/14250 battery with a 4SR44 or 4LR44 battery can damage the device or cause it to malfunction.

Therefore, never replace a 1/2 AA/14250 battery with a 4SR44 or 4LR44 battery.

Frequently Asked Questions (FAQ)

Below are some common questions about 1/2 AA and 14250 batteries:

What battery can replace a 14250?

Any lithium battery with a nominal voltage of 3.0V and dimensions of 14.0 x 25.0 mm can replace a 14250 battery, regardless of the label (1/2 AA, 14250, CR14250, etc.), as long as the original battery is 3.0V.

If the original battery is 3.6V, choose a replacement with the same voltage (3.6V) and dimensions (14.0 x 25.0 mm).

What is the 14250 battery used for?

The 14250 battery’s applications vary depending on its chemistry, but it is commonly found in medical devices, security systems, CMOS memory backup, dog collars, certain remote controls, compact LED flashlights, laser pointers, and similar devices.

Can two 1/2 AA batteries be used instead of one AA battery?

No. Using two 1/2 AA batteries in place of a single AA battery is not recommended, as the voltage difference can damage the device.