It can be hard to know what you’re looking at when it comes to zinc based batteries, because the terminology can get mixed around a little. Here’s some clarity:
- If someone refers to the Leclanché cell, they mean zinc-carbon.
- If someone refers to heavy duty zinc-carbon (or extra heavy duty or super heavy duty), they mean zinc-chloride.
- If they are the cheapest battery in the shop and they don’t say what chemistry they are, then they are probably zinc-carbon batteries.
What’s the difference?
In chemical terms, Zinc-chloride uses purer materials, making it slightly more expensive to manufacture.
Eveready’s own comparison shows this stark difference when it comes to rates of discharge. When fitted to a high drain device such as a motor toy, zinc-chloride will last 3 times longer than zinc-carbon. When powering a low drain device such as a radio, zinc-chloride is 180% better. As such, when considering the cost-benefit, it very much depends on what sort of device you will be using the battery in.
In short, the higher the drain, the better the performance of zinc-chloride compared to zinc-carbon when using the same size battery. This is only because the zinc-carbon units have a higher internal resistance (which wastes energy), during high rates of discharge. As such, a large zinc-carbon battery can have a similar performance to a smaller zinc-chloride unit (and a similar cost), because the bigger product has a lower internal resistance.
Zinc-chloride also offers a marginally higher cell voltage (1.6 volts) compared to zinc carbons 1.55 volts, but in most applications this is so slight any difference in performance is not noticeable.