3LR12 4.5 Volts Flat Battery
Alkaline 3LR12 battery is a flat, rectangular battery, containing internally three "B" cells connected in series to form the 4.5 volts battery pack.
Once upon a time, the 3LR12 4.5V battery was a very common battery used in various applications, but nowadays it is mostly used in flashlights, toy remote controllers, and similar applications.
Published: May 27, 2021.
3LR12 Battery Features and Specifications
3LR12 battery feature physical dimensions of (H x L x W) 67 x 62 x 22 mm (~2.638 x 2.441 x 0.866 inches) - internally, it contains 3 (three) "B" cells (D x H: 21.5 x 60 mm) connected in series to provide the required 4.5 volts.
3LR12 4.5V battery is based on the Zinc-Manganese Dioxide (Zn-MnO2) chemistry, also known as "Alkaline" chemistry - nominal voltage is 4.5 volts, cutoff voltage is 2.7 volts and nominal capacity in the 2000-3000 mAh range.
Note: nominal capacity depends on various factors, including temperature, battery age, drain current, and similar.
Flat rectangular 4.5 volts batteries feature top battery terminals in the form of metallic strips, each 6-7 mm wide with the positive battery terminal being shorter than the negative battery terminal.
The most common labels for 4.5V 67 x 62 x 22 mm flat rectangular battery are MN1203, 3LR12, 3R12, 1289, Type 3336, 4912 etc.
Zinc Carbon (3R12) vs Alkaline (3LR12) 4.5V Battery
Zinc-carbon 4.5V battery is commonly labeled as 3R12 battery and is used as a cheaper alternative to the alkaline 3LR12 battery, especially for low drain devices.
On average, zinc-carbon 3R12 battery weighs 105-115 grams and features a nominal capacity of 1000-1500 mAh, while alkaline 3LR12 battery weighs 160-180 grams and features a nominal capacity of 2000-3000 mAh.
Also, the shelf life of zinc-carbon batteries is rarely longer than 2-3 years, while alkaline batteries can have a shelf life of up to 5-7 years.
Personally, due to the small, almost negligible price difference, alkaline 3LR12 batteries are highly recommended due to the more stable output voltage, higher capacity, longer shelf life, etc. for both low-drain and high-drain devices.
Long Story Short: If You are looking for a flat 4.5V rectangular 67 x 62 x 22 mm battery, go for the 3LR12 battery from reputable brands - this is an alkaline battery, designed as a heavy-duty battery and already tested by countless real-life users...
But, if You need a low-drain battery for a device that will be used only occasionally, a 3R12 (zinc-carbon) battery can save You some money...