The voltage (V) of a battery indicates the amount of voltage that is present at the connection of the battery. For example, tool batteries can have 9.6v, 14.4v or 18 volts at the connection points. The higher the voltage, the less amperage is needed to achieve the same effect. In other words, an 18v cordless drill uses less power than a 10.8v machine to achieve the same result.
The correct voltage is of great importance for the charger and the charging technique. An incorrect charging voltage has a negative effect on the lifespan of your battery and can possibly lead to an explosion of the battery. The use of a charger that is not prescribed for your type of battery is therefore strongly discouraged.
