CBG Workshop
Most of our bikes run a battery. If you run a dynamo, magneto and a kick-start, it may just be to power the lights, as the magneto provides the spark. You may run an alternator and kick-start, in which case the battery needs to power the spark, and if you have an electric start, then it has to power the starter, too.
This growing amount of jobs increases the power needed from the battery, which in turn increases the physical size. Older bikes tend to use six-volt systems that tend to have three two-volt cells, while 12-volt batteries have six two-volt cells, hence they are larger to help cope with better lights, starters and larger motors.
They all have various numbers on them, which is important when getting a replacement – for example, the dimensions so it fits six or 12 volts, and where the terminals are located. There will also be CCA (cold crank amps), which gives you an idea of how powerful that initial burst of power the battery can deliver. A leisure battery for a caravan, for instance, will not have this. There will also be amp hours, or Ah. This is a guide to how long a battery will last with a constant drain on it; for example, a 14Ah battery can provide 14 amps for one
