4SR44, 4LR44, PX28A, A544, 28A, K28A Battery Equivalents and Replacements
4SR44 or 4LR44 battery is a small cylindrical battery often used in dog collars, film cameras, small LED flashlights, car security systems, remote controls, toys, and similar.
Common labels for this battery are 4SR44 or 4LR44, depending on the exact chemistry, but there are many other labels that may confuse the user, including PX28A, A544, 28A, K28A, K28L, V34PX, 476A, 4A76, 2CR1/3N, 2CR11108, etc.
Updated: March 30, 2023.
4LR44, 4SR44, A544, PX28L Batteries Features and Specifications
Physical dimensions of the 4LR44/4SR44 batteries are 25.2 mm in height and 13 mm in diameter (~0.992 x 0.518 inches), with their labels (4LR44 or 4SR44) describing their internal construction - four LR44 or SR44 batteries stacked vertically.
Thus, some manufacturers even deliver their devices powered by 4SR44 or 4LR44 batteries with the small plastic battery holder, allowing the use of single 4LR44/4SR44 batteries, or four LR44/SR44 batteries, or even two CR11108 (CR1/3N, 2L76, 2LR44) batteries.
Note: four LR44/SR44 or two CR11108 or CR1/3N batteries stacked vertically feature a diameter of 11.6 mm and a height of 21.6 mm, thus requiring a battery holder to fit a 25.2x13 mm battery compartment.
The typical capacity of the 4LR44 alkaline battery is 130-170 mAh, and around 150-200 mAh for the 4SR44 battery, with the most important features given in the following chart:
|Nominal Voltage||6.0 volts||6.2 volts|
|End-Point Voltage||3.6 - 4.0 volts||3.6 - 4.8 volts|
|Notes||Voltage drops over time||Very constant voltage|
|Typical Labels||4SR44 (silver-oxide), 4LR44 (alkaline), PX28A, A544, K28A, K28L, V34PX, 28A, 476A, 4A76, 2CR1/3N, 2CR11108|
|Typical Capacity||130-170 mAh||150-200 mAh|
Typical labels of these 25.3x13 mm non-rechargeable batteries are 4SR44, 4LR44, PX28A, A544, K28A, K28L, V34PX, 28A, 476A, 4A76, 2CR1/3N, 2CR11108, but believe or not, there are other labels as well.
Generally, 4LR44 is an alkaline battery, 4SR44 is a silver-oxide battery, while 2CR1/3N or 2CR11108 are typically non-rechargeable lithium batteries.
Also, some manufacturers offer lithium 13 x 25.2 mm batteries, often labeled as PX28L or 2CR1/3N, featuring two Lithium Manganese Dioxide batteries connected in series for a nominal voltage of 6.0V - a typical example is Duracell PX28L (2CR1/3N) battery.
Fortunately, to sell their batteries, manufacturers write down several labels, often their in-house label, and the battery's chemistry.
The capacity and cutoff voltage of 4LR44/4SR44 batteries depends on the drain current and the device being powered by these batteries.
For example, Energizer A544 battery is an alkaline battery consisting of four LR44 batteries connected in series, featuring a metal jacket.
Their typical capacity is 178 mAh when being discharged over 30kΩ at 21°C down to 3.6 volts.
While 178 mAh is an excellent capacity for LR44 or 4LR44 battery, not every electronic device can operate with such low input voltage (most do, but if not sure, check the documentation, and if the cutoff voltage of your device is 4.0 or more volts, expect somewhat lower actual capacity.
Varta V28PX battery is a high-drain silver-oxide 4SR44 battery with a nominal voltage of 6.2 volts and a typical capacity of 145 mAh when discharged using a 20kΩ load at 20°C down to 3.6 volts.
Despite being a silver-oxide battery, Varta V28PX features lower nominal capacity than alkaline Energizer A544 (145 vs. 178 mAh), but the drain current of the Varta V28PX is almost twice as strong as Energizer A544 current (310 vs. 160 μA), despite having load 'just' 33% lighter (20 vs. 30 kΩ), thanks to the higher voltage and lower internal resistance of the high-drain silver-oxide batteries.
So, in this example, which one is better, alkaline Energizer A544 or silver-oxide Varta V28PX?
Obviously, if you have to choose between these two models, for low-drain devices, go for Energizer A544, and for high-drain devices, go for the Varta V28PX battery.
Like all other similar batteries, 4LR44 and 4SR44 batteries feature, on average, 3-5 years shelf life, with some low-drain models used as motherboard batteries feature 5-7+ years shelf life.
4LR44, 4SR44, PX28L Batteries Comparison Chart
The following comparison chart lists some of the most popular cylindrical 6V 13.0 x 25.2 mm batteries:
|Battery Datasheet||Capacity||Operating Temperatures||Annual Self-Discharge Rate||Discharge Currents|
|Duracell PX28L (2CR1/3N)
Lithium Manganese Dioxide
|160 mAh nominal, 185 mAh rated, 30kΩ down to 4.0V @20°C||-20°C to +75°C||<1% @20°C||2.7 mA std. cont.|
|178 mAh, 30kΩ down to 3.6V @21°C||-||-||0.16 mA std. cont.|
|-||-||3-year shelf life||-|
|120 mAh, 27kΩ down to 3.6V||-10°C to +45°C||-||-|
|160 mAh||-||3-year shelf life||-|
|145 mAh, 20kΩ down to 3.6V @20°C||-10°C to +60°C||-||0.32 mA std. cont.|
Of course, there are many other models on the market.
As one can see, Lithium Manganese Dioxide (LiMnO2) chemistry offers similar performances in terms of capacity.
However, such batteries are excellent for low-current and standby performances but also for high-drain pulse discharges.
When compared with alkaline and silver-oxide batteries which have 4 (four) batteries connected in series, lithium batteries feature 2 (two) batteries connected in series.
4LR44/4SR44 Battery Safety Issues
Although 4LR44/4SR44 batteries are not the smallest batteries on the market, kids and pets may try to swallow them.
If that happens, call immediately local emergency services and do as you are told - modern 4LR44/4SR44 batteries don't contain mercury, cadmium, or similar heavy metal, but when swallowed, they start electrolytic processes in human/animal body that can be rather dangerous and can cause chemical burns.
Long Story Short: When looking for a 4LR44/4SR44/PX28L/A544 battery equivalent or replacement, go for a 4LR44/4SR44 battery from a reputable brand and go for the most popular models with good reviews.
4LR44/4SR44 are rather common batteries, they are manufactured by most battery brands and are available around the world in various hardware stores and online shops.
Some of the most popular 4LR44 and 4SR44 models include (Amazon links, the links open in the new windows):
- PetStandard 4LR44 6V Battery
- Energizer 4LR44 A544 6V Battery
- GoodBoy 4LR44 6V Battery
- Panasonic 4SR44 6.2V Battery
4SR44 batteries usually cost more than 4LR44 batteries, but they are more energy-dense batteries, offering more stable output voltage. But, nonetheless, 4LR44 batteries are still more popular.