: As batteries age, they lose capacity; for example, lithium-ion batteries often follow the 40–80 rule (maintaining charge between 40% and 80%) to delay this decay.
When purchasing, the "total cost" includes the initial price and the value of the protection plan. buy new battery
: Many manufacturers offer pro-rata or full-replacement warranties. For instance, brands like Interstate Batteries define a "replacement battery" specifically as one purchased at an adjusted price based on previous warranty terms. : As batteries age, they lose capacity; for