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Examoogle • User • info@examoogle.com • EE-2024-8821
Chapter 1 of 12 • Page 1 of 248🔒 Protected PDF • Watermarked
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A dead storage battery can be revived by
adding
adding so-called battery restorer
dose of H₂SO4₄
none of above
none of above
Quick Summary: A dead lead-acid storage battery refers to one that has undergone deep discharge or sulfation. None of the listed options (adding water, restorers, or extra sulfuric acid) can reverse the chemical degradation caused by lead sulfate crystallization on the plates.
A dead lead-acid storage battery refers to one that has undergone deep discharge or sulfation. None of the listed options (adding water, restorers, or extra sulfuric acid) can reverse the chemical degradation caused by lead sulfate crystallization on the plates.
Pb+PbO2+2H2SO4↔2PbSO4+2H2O — The double displacement reaction governing battery operation
In a lead-acid battery, the discharge reaction is Pb+PbO2+2H2SO4→2PbSO4+2H2O. During a 'dead' state, large, hard crystals of lead sulfate (PbSO4) form on the plates (sulfation), which are insoluble and electrically non-conductive. Adding chemicals or extra acid cannot dissolve these hardened crystals; instead, they often cause further internal damage, corrosion, or short circuits.
Hardened lead sulfate crystals are non-conductive and prevent charge acceptance.
Adding sulfuric acid to a discharged battery is dangerous and does not convert the lead sulfate back to active materials.
Battery 'restorers' are largely ineffective against advanced sulfation.
Prevention is key: keeping the battery fully charged prevents crystallization.
None of the proposed methods are valid professional maintenance techniques.
Adding acid to a battery can lead to casing corrosion and thermal runaway.
Attempting to revive dead batteries manually can lead to hydrogen gas leaks.
Automotive starter systems
UPS and emergency power backup
Battery restorers usually contain chemical additives meant to break down sulfates, but they do not reverse the physical growth of hard lead sulfate plates.
The only valid way to handle a sulfated battery is using pulse-width modulation (PWM) desulfator chargers, not chemical additives.
D is correct — None of the listed additives can reverse the physical chemical changes of deep plate sulfation in a dead battery.
In exams, remember that chemical additives in batteries are generally myths; battery health is purely an electrochemical balance controlled by charging cycles, not additive chemicals.