Batteries

All you need to know about batteries.

Summary

There are various types of battery based on different chemistries. To get the best out of them and to avoid problems you need a basic understanding of their advantages and disadvantages, as well as a little about purchasing, maintaining and disposing of them.

Safety

• Old batteries often leak, causing corrosions of the battery contacts, so preventing new batteries from working.
• Lithium batteries can catch fire and burn violently if over-charged, shorted, punctured, or physically damaged in any way.
• Button cells must be kept away from small children. If swallowed, this is a medical emergency as death can result in just a few hours, as a result of electrochemical action in the stomach.

How batteries work

(You can skip this section if you like, though a little more knowledge than you actually need is always helpful.)

Non-rechargeable (primary) batteries

Type	Advantages	Disadvantages	Comments
Zinc carbon and zinc chloride	Cheap. Available in standard shapes and sizes.	Short life and slow death.	Zinc chloride is a heavier duty version of zinc carbon. Alkaline batteries are preferred in almost all applications.
Alkaline	Good life at a reasonable cost. Available in standard shapes and sizes, and also as button cells as cheap alternatives to silver and mercury.		This is the most economic general purpose type.
Silver and Mercury	Long life	Relatively expensive Can only deliver a small current	Normally only available as button cells for watches and calculators.
Lithium	Very long shelf and service lives.	Relatively expensive.	Mainly used in smoke alarms and cameras.

External links

• Battery University