Charging Time Required

The time required to charge a battery will vary depending upon the following factors:
^ Size of Battery - A higher capacity battery which is completely discharged requires more time to charge than a completely discharged smaller capacity battery.
^ Temperature - The colder the battery, the more time it takes to charge. When a fast charger is connected to a cold battery, the current accepted by the battery will be very low at first. As the battery warms up, it will accept current at a higher rate.
^ Charger Capacity - The higher the charger amperage, the less time it will take to charge the battery.
^ State of Charge - A completely discharged battery requires more than twice as much charge as a half-charged battery. In a completely discharged battery, the electrolyte is nearly pure water and is a poor conductor; the current accepted by the battery is very low at first. Later, as the charging current increases the acid content in the electrolyte, conductivity will increase and the battery will accept a higher charge current. Any battery which is discharged and stays discharged for a period of time may not readily accept a charge. If charged long enough most batteries can be used again. If a battery is extremely discharged and stays that way for a prolonged time, it can be permanently damaged. This damage can be accelerated by high temperatures. Also, extremely discharged batteries can freeze at temperatures as high as -7°C (20°F). If a vehicle is not going to be used for 20 days or more, follow the procedures under "Battery Protection During Vehicle Storage" to prevent battery damage.