1. Replace the battery when either of the following conditions exist.

•	The hydrometer is clear or yellow.

•	The battery is frozen.

2. Always stop charging, or reduce the charging rate, if either of the following conditions exists:

2.1.	The battery temperature is 52°C (125°F) or higher.

2.2.	Electrolyte spews or gasses violently through the vent holes.

The time required to charge a battery will vary depending upon the following factors:

1. The size of the battery - A completely discharged, large, heavy-duty battery requires more than twice the recharging time as a completely discharged, smaller battery.
2. The temperature - A longer time is needed to charge any battery at -18°C (0°F) than at 27°C (80°F). When a fast charger is connected to a cold battery, the current accepted by the battery is very low at first. Then, as the battery warms, the battery accepts a higher rate of current.
3. The charging capacity - A charger which can supply only five amperes requires a much longer charging period than a charger that can supply 30 amperes or more.
4. The state-of-charge - A completely discharged battery requires more than twice as much charge time as a half charged battery. Because the electrolyte is nearly pure water and a poor conductor in a completely discharged battery, the battery accepts very low current at first. Later, as the charging current causes the electrolyte acid content to increase, the charging current also increases.