1/2 AA Battery vs 14250 Battery

1/2 AA and 14250 batteries are very popular small, cylindrical batteries, commonly used in electronic meters, security systems, medical equipment, baby movement monitors, dog collars, compact EDC flashlights, and similar.

1/2 AA and 14250 batteries are very similar batteries that their labels are often used interchangeably. 1/2 AA and 14250 batteries share practically the same dimensions, but they differ in exact battery chemistry and hence battery's characteristics and performances.

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Features and Specifications

1/2 AA and 14250 battery share practically the same physical dimensions of (D x H) 14.0 x 25 mm, with a maximum allowed diameter of 14.5 mm. Some batteries feature 25.4 mm (1-inch) height, but slight variations in height is of lesser problem for battery compartments than the battery's diameter.

Most common labels for small, cylindrical, lithium 14.0x 25.0 mm batteries are 1/2 AA, 14250, CR14250, ER14250, etc. Some labels are often used almost exclusively with a certain chemistry, but that is not always the case.

So, when buying 1/2 AA/14250 batteries, check the label, but also a nominal voltage, capacity, and if present, chemistry type.

Non-Rechargeable 1/2 AA and 14250 Batteries

The most common chemistry types of non-rechargeable 1/2 AA and 14250 batteries are:

- LiMnO2 (Lithium-Ion Manganese Dioxide) battery uses manganese dioxide MnO2, as the cathode material and feature a nominal voltage of 3.0 volts and a nominal capacity in the 900-1000 mAh range. Actual capacity depends on the device's cutoff voltage, drain current, temperature, and similar.

LiMnO2 batteries often feature 'CR' as part of their label, for example, 'CR 1/2 AA' or 'CR14250' and similar.

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Lithium-Ion Manganese Dioxide batteries offer stable output voltage, long shelf life (up to 10 years), and wide operating temperature range (usually between -20°C (-4°F) and 70°C (158°F)) and are commonly used as motherboard batteries and for other similar equipment. However, these batteries are slowly being replaced by Lithium Thionyl Chloride (Li-SOCl2) batteries for low- and high-temperatures (especially low-temperatures) and for low-drain applications.

- Li-SOCl2 (Lithium Thionyl Chloride) battery uses thionyl chloride SOCl2 as a cathode and features a nominal voltage of 3.6 volts and a nominal capacity of around 1200 mAh.

Lithium Thionyl Chloride batteries offer stable output voltage, extra-long shelf life (10+ years), extra-wide temperature operating range (some models from -55°C to +85°C; -67°F to +185°F), higher capacity, higher energy density, etc.

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14.0 x 25.0 mm Lithium Thionyl Chloride batteries are often labeled as 'ER14250 batteries', but other labels are used as well, like 'ER 1/2 AA' or similar.

Note: most newer devices being powered by 14.0 x 25.0 mm batteries accept both 3.0V and 3.6V batteries, with 3.6 volts slowly becoming 'standard' voltage for these batteries. However, 'CR 1/2 AA' batteries are very popular chemistry and in the end, very safe chemistry - if You have a device that is being powered by a 3.0V 1/2 AA battery and you don't have any other information about your device, do NOT replace the battery with 3.6 volts model - this 0.6 volts is not a large difference, but it can cause issues, or it can even destroy sensitive devices...

Rechargeable 1/2 AA and 14250 Batteries

Rechargeable 14.0 x 25.0 mm batteries are based on a lithium-ion chemistry, and feature a nominal voltage of 3.2 - 3.7 volts, depending on the exact chemistry:

- IMR 14250 batteries feature LiMn204 (Lithium Manganese Oxide) chemistry and a nominal voltage of 3.6 - 3.7 volts.

- INR 14250 batteries feature LiNiMnCoO2 (Lithium Manganese Nickel) chemistry and a nominal voltage of 3.6 - 3.7 volts.

- IFR 14250 batteries feature LiFePO4 (Lithium Iron Phosphate) chemistry and a nominal voltage of 3.2 - 3.3 volts

- ICR 14250 batteries feature LiCoO2 (Lithium Cobalt Oxide) chemistry with a nominal voltage of 3.6 - 3.7 volts. ICR 14250 batteries commonly have higher capacities, but maximum allowed currents are often limited, which is usually not an issue for 14250 battery applications.

There are other chemistries on the market too, but these are the most common ones, with ICR 14250 being the most popular.

Rechargeable 14250 batteries feature a nominal capacity of 280-350 mAh, although their capacity depends on the drain current.

Also, when compared with CR 1/2 AA and especially with ER14250 batteries, 14250 batteries feature a much higher self-discharge rate.

But, 14250 can be recharged 500+ times, saving plenty of money where their usage is suitable.

14250 battery charger

Note: Lithium-ion batteries should be charged only with the battery chargers intended for these batteries, or they can overheat and burst to flames and even explode.

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

1/2 AA/14250 batteries feature a nominal size of 14.0 x 25.o mm while AA batteries feature a nominal size of 14.5 × 50.5 mm and 14500 batteries feature a nominal size of 14.0 x 53.0 mm.

For short, 1/2 AA/14250 batteries feature a very similar diameter (~14 mm) to AA/14500 batteries and approximately half the height of the AA/14500 batteries.

aa battery 3Theoretically, two 1/2 AA/14250 batteries can replace a single AA/14500 battery in most battery compartments, but the actual problem are voltages:

- two 1/2 AA/14250 batteries feature 6.0 - 7.2 volts,

- single AA battery features 1.2 - 1.8 volts (commonly ~1.5 volts),

- single 14500 battery features 3.2 - 3.7 volts.

This voltage difference can easily destroy most electronic devices, thus NEVER replace your AA/14500 battery with a pair of 1/2 AA/14250 batteries.

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

4LR44/4SR44 batteries feature nominal dimensions of 13 x 25.2 mm in diameter with their labels (4LR44 or 4SR44) describing its internal construction - four LR44 or SR44 batteries stacked vertically.

4sr44 mThus 4LR44 battery features a nominal voltage of 6.0 volts, while the 4SR44 battery features a nominal voltage of 6.2 volts.

Because of very similar dimensions between 1/2 AA/14250 battery and 4SR44/4LR44 battery (14.0 x 25.0 mm vs 13 x 25.2 mm), it is possible to easily replace 1/2 AA/14250 battery with a single 4SR44 or 4LR44 battery.

However, due to the voltage difference, the device will probably be destroyed or in the best-case scenario, it will not function properly - thus NEVER replace your 1/2 AA/14250 battery with 4SR44 or 4LR44 battery.


Long Story Short: If You are looking for a small, cylindrical 14.0 x 25.0 mm battery replacement, You need 3.0 volts non-rechargeable battery (common labels '1/2 AA', 'CR 1/2 AA', 'CR14250'), 3.6 volts non-rechargeable battery (common labels 'ER 1/2 AA', 'ER14250') or 3.6 volts rechargeable battery (common label '14250').

When replacing these (or any other) batteries, never change the battery chemistry unless explicitly allowed by the manufacturer of your device.