Introduced as a publicly available product in the 1960s, Alkaline batteries are now produced in their billions every year and are the world’s most popular household battery. You’ll find them in remote controls, toys, cameras, radios, flashlights and a whole lot more – either in disposable or rechargeable versions.
They were a major step forward compared to the zinc-chloride cells of the day, offering three to five times the capacity.
‘Alkaline’ is their descriptive name, because they use an alkaline electrolyte of potassium hydroxide.
Basic structure of an alkaline battery
The elements are as follows:
- Anode material – usually zinc based.
- Cathode Material – usually manganese based paste.
- An ion conducting separator soaked in alkaline electrolyte.
- A metallic case and positive terminal.
- A collector pin which is connected to the negative terminal. In the coin/button version the collector material is applied to the inside of the terminal.
- A gasket to separate the negative terminal from the case. This often incorporates a vent to release any pressure build up caused by abuse or malfunction.
Alkaline battery sizes
Alkaline batteries are most commonly available as:
- D cells
- C cells
- AA Cells
- AAA Cells
- AAAA cells
- N Cells
- 9Volt cells
- Button Cells
Alkaline batteries vs lithium
Compared to lithium batteries, alkaline offers a higher voltage, giving off fast bursts of power to items such as camera flashes. However, both the voltage and the mAh capacity decline as the battery discharges. Lithium on the other hand remains constant until close to full discharge, making them better for applications such as laptops, which need consistent power.
Alkaline batteries don’t have the operating life of their lithium counterparts which can last two to three times longer. The drawback of a lithium is that it is often priced at double that of an alkaline making the actual usage/cost benefits questionable.
When it comes to backup power, Alkaline has the edge. Like all batteries, it self-discharges when not in use, but only at a rate of around 2% per year . This discharge is similar to lithium metal, but much lower than lithium-ion.
Alkaline batteries vs Nickel
Compared to many rechargeable batteries (such as Nickel based), Alkaline is heavier in weight, but has a varying lifespan. It’s all about how much the current drains. In a high drain device like a digital camera, the lifespan of an alkaline battery is much shorter. In a low drain device such as a remote control, it will last longer.
Alkaline also offers a better choice for devices that simply need standby power, such as smoke alarms. They self-discharge at around 2% per year compared to nickel-based units, which would be nearly flat after 12 months even when never used.
With button batteries, alkaline are the budget option, with their price reflecting this. With less capacity than silver oxide or lithium, they simply won’t last as long in applications.
With cost and a long shelf life being their major advantages, alkaline batteries are often chosen when a device manufacturer ships a product with ‘batteries included’. You’ll also find them in backup power sources where recharging isn’t available (such as smoke alarms). In general alkaline are definitely a popular choice as the budget offering for common household batteries.