B-Cell Batteries: Why There Are No B Batteries?
B-cell batteries, also known as B batteries, are cylindrical zinc-carbon or alkaline batteries that were used in various applications, especially as part of the flat 4.5V batteries.
Today, B batteries are practically impossible to find on the market since other similar battery sizes are much more popular, including AA, C, and D-size batteries. Also, with the advances in chemistry and technology, lithium cylindrical cells, especially rechargeable ones, are taking their share of the market.
Published: October 7, 2022.
B Battery: Dimensions and Features
B-cell batteries are cylindrical, non-rechargeable batteries with physical dimensions of (D x L) 21.5 x 60.0 mm (~0.846 x 2.362 inches) and use two popular battery chemistries, zinc-carbon and alkaline chemistry.
- Zinc-Carbon B Battery, also known as R12, has a typical capacity of 1000-1500 mAh,
- Alkaline B Battery, also known as LR12, has a typical capacity of 2000-3000 mAh.
Note: some sources claim alkaline b battery capacity of up to 6000-8350 mAh - although capacity depends on the temperature, battery age, discharge current, and similar, it is really hard to imagine that LR12 battery features such large capacity ...
The nominal voltage is 1.5 volts, while the cut-off voltage is usually in the 0.8-1.0V range, and it also depends on the device being powered.
While B-cell batteries are very rare today, they are used for making flat 4.5V batteries labeled 3R12 (Zinc-Carbon) and 3LR12 (Alkaline), where three B-cell batteries are connected in series.
Thus, 3R12/3LR12 battery features physical dimensions of (H x L x W) 67 x 62 x 22 mm (~2.638 x 2.441 x 0.866 inches).
So, if You have ever wondered why there are no B batteries on the market, the reason is actually very simple - there are other battery sizes that are far more popular, and B-size batteries never actually catch on among the users.
But, 3LR12/3R12 4.5-volts flat batteries are still being used for powering toys, flashlights, some gadgets, and similar devices.
Note: This is a photo of Varta's 3LR12 (3x B-cell battery) flashlight with an incandescent light bulb and a very simple mechanical switch. It was manufactured, I guess, in 70is or 80is, and it still works.