The correct answer is: A. 10% of capacity.
A lithium-ion battery should be charged at a rate of 10% of its capacity. This means that if you have a 1000mAh battery, you should charge it at a rate of 100mAh. Charging at a higher rate can damage the battery and shorten its lifespan.
Option B is incorrect because 20% of capacity is too high. Charging at a rate of 20% of capacity can damage the battery and shorten its lifespan.
Option C is incorrect because 30% of capacity is too high. Charging at a rate of 30% of capacity can damage the battery and shorten its lifespan.
Option D is incorrect because 40% of capacity is too high. Charging at a rate of 40% of capacity can damage the battery and shorten its lifespan.
It is important to note that the charging rate of a lithium-ion battery can vary depending on the type of battery, the charger, and the temperature. It is always best to consult the manufacturer’s instructions for the specific battery you are using.