How does the internal resistance of a battery affect charging efficiency and heat generation?

How does the internal resistance of a battery affect charging efficiency and heat generation?

• A. Higher internal resistance increases charging efficiency.
• B. Higher internal resistance reduces charging efficiency but also reduces heat during charging.
• C. Higher internal resistance reduces charging efficiency, causes more heat during charging, and reduces maximum deliverable current.
• D. Higher internal resistance only affects the current during high-state-of-charge.

Answer: (C)

When charging, energy is pushed into the chemical storage inside the cell, but the cell’s own internal resistance dissipates part of that energy as heat. The heat produced inside is P = I^2 R, so a higher internal resistance means more energy is wasted as heat and less becomes stored, lowering charging efficiency. Additionally, the voltage drop inside the cell is I times the internal resistance, so with a larger R, the terminal voltage for a given charging current is reduced. That limits how much current can be safely and effectively delivered, reducing the maximum deliverable current. In short, higher internal resistance leads to more heat during charging, lower efficiency, and a lower maximum charging current.

When charging, energy is pushed into the chemical storage inside the cell, but the cell’s own internal resistance dissipates part of that energy as heat. The heat produced inside is P = I^2 R, so a higher internal resistance means more energy is wasted as heat and less becomes stored, lowering charging efficiency. Additionally, the voltage drop inside the cell is I times the internal resistance, so with a larger R, the terminal voltage for a given charging current is reduced. That limits how much current can be safely and effectively delivered, reducing the maximum deliverable current. In short, higher internal resistance leads to more heat during charging, lower efficiency, and a lower maximum charging current.