Throughout this site we use many technical terms, and given the breadth of readership our site enjoys, sometimes we are remiss and incorrectly assume everyone knows what we are referring to. For those that do not, here are some explanations of the technical terms use.
A device for restoring the charge of a battery. It consists, essentially, of a mains transformer to reduce household mains current (in Britain, 240 volts AC) to 12 volts DC. A built-in rectifier changes the alternating current to direct current. As a rule, a domestic battery charger has an output of about 2 amps although they can be obtained to charge as high as 6 amps. The more sophisticated models have an ammeter built in to check the charging rate and an automatic limiter which reduces the output as the battery charge rises (6-volt chargers are also available).