A laptop battery reports 85% wear level after two years. What does this indicate?

Correct answer: The battery can only hold 15% of its original capacity

Option A is correct because battery wear level (also called wear leveling or design capacity loss) represents the percentage of the battery's original maximum capacity that has been permanently lost; an 85% wear level means the battery can now hold only 15% of its factory-rated capacity. Option B is wrong because the wear level is not the same as the current charge state; a battery at 85% charge still has most of its remaining capacity available at that moment. Option C is wrong because battery wear is a physical chemical degradation of the cells and cannot be corrected by a firmware update. Option D is wrong because an 85% wear level means the battery has lost 85% of its original capacity, not 15%, so Option D inverts the correct interpretation described in Option A.