The current and voltage characteristics of a lead-acid battery depend on its design and application. Here are some general guidelines.
Voltage
- Nominal Voltage: The nominal voltage of a single lead-acid cell is 2 volts.
- 6-Volt Battery: Consists of 3 cells in series (6V).
- 12-Volt Battery: Consists of 6 cells in series (12V).
- 24-Volt Battery: Consists of 12 cells in series (24V).
Charging Voltage
- Float Charge: The voltage used to maintain the battery at full charge, typically around 2.2 to 2.3 volts per cell (13.2 to 13.8 volts for a 12V battery).
- Cyclic Charge: The voltage used for charging the battery during use, usually around 2.4 to 2.45 volts per cell (14.4 to 14.7 volts for a 12V battery).
Discharging Voltage
- Full Charge: Around 2.1 to 2.2 volts per cell (12.6 to 13.2 volts for a 12V battery).
- Discharged: Around 1.75 to 1.8 volts per cell (10.5 to 10.8 volts for a 12V battery).
Current
- Capacity Rating (Ah): Lead-acid batteries are rated in ampere-hours (Ah), which indicates the amount of current the battery can supply over a specific period (usually 20 hours). For example, a 50 Ah battery can supply 2.5 amps for 20 hours.
- Maximum Discharge Current: Depends on the battery design and application. For example, starting batteries (used in vehicles) can supply very high currents (hundreds of amps) for short periods, while deep-cycle batteries are designed to provide lower currents over longer periods.
- Charging Current: Typically, the charging current should be around 10% of the battery’s capacity (C/10 rate). For a 50 Ah battery, this would be about 5 amps. However, this can vary based on the battery type and manufacturer recommendations.
Specific Applications
- Automotive Batteries: Typically 12V with high cold cranking amps (CCA) for starting engines.
- Deep-Cycle Batteries: Designed for continuous use and deeper discharge cycles, often used in applications like solar power storage, marine, and RVs.
- UPS Batteries: Used in uninterruptible power supplies, typically 12V or 24V, with a focus on providing steady power over short durations during power outages.
Always refer to the manufacturer’s specifications for precise voltage and current ratings for a specific lead-acid battery model.
