Can You Mix Zinc and Alkaline Batteries?
While it is generally true that mixing batteries of different types can lead to suboptimal performance, the degree of impact depends on the device. Low-power devices such as wall clocks, TV remotes, calculators, electric toothbrushes, AM/FM radios, and doorbell transmitters may not exhibit significant issues.
Why Mixing Zinc and Alkaline Batteries is Inadvisable
No, it is not advisable to mix zinc and alkaline batteries in the same device. Here are a few reasons why:
Different Chemistries
Zinc batteries, such as zinc-carbon and alkaline batteries, use different chemical reactions to generate power. This can lead to uneven discharge rates, which can affect the performance of the device.
Voltage Differences
While both types of batteries typically have a nominal voltage of 1.5 volts, their voltage under load can differ. This can cause the device to operate improperly or not at all. For example, an alkaline battery might provide a slightly higher voltage under load than a zinc-carbon battery, leading to potential damage or malfunction.
Leakage Risk
Mixing different battery types can increase the risk of leakage, which can damage the device. Alkaline batteries, particularly high-quality ones, are designed with anti-leak features to prevent damage and extend shelf life. Mixing with zinc batteries can negate these safeguards, leading to potential leaks and device damage.
Reduced Performance
If you mix zinc and alkaline batteries, the overall performance of the device may suffer, leading to shorter battery life and potential malfunctions. The zinc-carbon cells often deplete faster, placing additional stress on the alkaline cells and reducing the device’s operational time.
For optimal performance and safety, it is best to use the same type and brand of batteries in any device.
Understanding Zinc and Alkaline Batteries
If you are unsure whether you can use both types of cells in one battery pack, it is possible for short-term fixes, but it is not advisable to mix chemistries in a battery pack. The one with a lower discharge rate tolerance will be stressed more, degrading faster, and exhausting sooner. The additional stress transfers to the other batteries, reducing the overall performance.
Chemical Composition
Non-rechargeable alkaline batteries are made with zinc and manganese dioxide as electrodes, and their electrolyte is either potassium or sodium hydroxide. They have a higher energy density and greater leakage resistance than zinc-carbon batteries. Zinc-carbon batteries mostly use ammonium chloride for the electrolyte.
Quality and Design
The higher quality alkaline batteries have an anti-leak design to prevent damage to devices and ensure a long shelf life. They generate gas when the rate of discharge is too high, and the improved sealing design, along with better sealing material and other added features, ensures a safer product.
Zinc carbon batteries are lower in energy density, have a lower discharge rate preference, and use less expensive materials. They are well-suited for low-drain devices. If you use zinc-carbon cells together with alkaline cells in the same battery pack, the zinc-carbon cells may be stressed more if the application requires a higher discharge current than zinc-carbon cells can handle. Since zinc-carbon cells are lower in capacity, they will deplete sooner than the alkaline cells, causing the device to stop operating properly sooner and putting additional stress on the alkaline cells.
How to Identify Zinc and Alkaline Batteries
To distinguish between zinc-carbon and alkaline batteries:
Zinc-carbon cells are less expensive and weigh less than alkaline cells. AAA or AA cells sold in dollar stores in 4-6 cells/pack are zinc-carbon cells. They are almost always labeled as 'Heavy Duty'. If you need lightweight devices such as remote controllers, electric shavers, or electric toothbrushes for a short trip that uses AA or AAA cells, zinc-carbon cells should be fine.However, it is best to use either all zinc-carbon or all alkaline cells in a battery pack to ensure optimal performance and safety.