What is the maximum load voltage that must not fall below for lead-acid batteries under load?

For lead-acid batteries, particularly when they are under load, it is critical to maintain a minimum load voltage to ensure proper performance and longevity of the battery. The maximum load voltage that should not fall below is approximately 2.05 volts per cell.

Lead-acid batteries consist of multiple cells connected in series, and each cell typically has a nominal voltage of around 2 volts. When these batteries are used in applications such as backup power supplies or starting batteries for vehicles, it is essential to keep the load voltage above 2.05 volts per cell to avoid irreversible damage and to ensure that the battery can provide efficient power.

Maintaining this voltage level helps prevent sulfation, a process where lead sulfate crystals form on the battery plates, which can occur if the battery is allowed to remain in a deeply discharged state. If the voltage drops below this threshold, it can lead to diminished capacity and may render the battery unable to hold a charge effectively. Therefore, 2.05 volts is established as a vital minimum voltage level under load conditions for lead-acid batteries.