Both R03 carbon battery and LR03 are AAA batteries. Their differences are:
R03 is a carbon AAA battery, and LR03 is an alkaline AAA battery.
Alkaline
electricity is 3-5 times larger than carbon electricity, and the
current of alkaline electricity is also larger than that of carbon
electricity.
Alkaline electricity is mainly used in wireless mice and keyboards, electric toys and digital products, while carbon electricity is mainly used in watches, calculators and remote controls.