Here is one example that shows a benefit of using a switch mode charger even at somewhat lower current levels. Consider a USB-port charging source that could be limited to 500mA output. For example, if designing with a battery with a capacity of 1000mAH, theoretically it could be charged up to a 1A rate if the power was available. With the USB port current limit however, this isn’t possible. If a linear charger is used, then the cell can only be charged at 500mA as limited by the source current. However, if a high-efficiency buck converter is used then the battery can be charged with 600 – 700mA current for much of its charging cycle, which allows faster recharging whenever possible.