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Over charging of chemical battery
produces excessive gassing
loosens the active material
increases the temperature resulting in buckling of plates
all of the above
all of the above
Quick Summary: Overcharging occurs when a battery continues to receive a charging current after it has reached full capacity. This excess energy is dissipated as heat and triggers chemical reactions that degrade the internal battery components, making all listed effects correct.
Overcharging occurs when a battery continues to receive a charging current after it has reached full capacity. This excess energy is dissipated as heat and triggers chemical reactions that degrade the internal battery components, making all listed effects correct.
Q=тИлIdt тАФ Total charge delivered to the battery exceeding rated capacity C
PheatтАЛ=Icharge2тАЛRintтАЛ тАФ Power dissipated as heat during overcharge state
During overcharging, the electrolysis of the electrolyte occurs, where 2H2тАЛOтЖТ2H2тАЛ+O2тАЛ. This produces excessive gassing. The release of gases and heat creates internal pressure and chemical instability, which softens and loosens the active material from the plates. Furthermore, the heat leads to thermal expansion and warping of the lead grids, commonly known as plate buckling.
Overcharging leads to accelerated degradation of lead-acid batteries.
Gassing causes loss of electrolyte (water) which requires replenishment.
Plate buckling can lead to internal short circuits within the battery cell.
Active material shedding reduces the effective surface area and capacity of the battery.
Permanent loss of battery capacity
Risk of internal short circuiting
Hazardous gas emission (hydrogen)
Thermal runaway risk
Modern battery management systems (BMS) are essential to prevent overcharging by monitoring voltage limits.
Option A is a result of electrolysis; Option B is a result of chemical degradation; Option C is a result of thermal expansion.
D is correct тАФ Overcharging initiates electrolysis, generates excessive heat, and causes mechanical degradation of the battery plates.
Always remember that charging a battery beyond its cutoff voltage (float voltage) is the primary cause of sulfation-related failures and physical battery damage.