There are several different types of batteries that can be used to power RC (radio-controlled) cars, each with their own unique characteristics. Some of the most common types include:

1. Nickel-Cadmium (NiCad) batteries: NiCad batteries are one of the oldest and most widely used types of batteries for RC cars. They are known for their durability and reliability and can be used in a wide variety of RC cars. However, they have a relatively low energy density and are relatively heavy, which can affect the performance and handling of the car.

2. Nickel-Metal Hydride (NiMH) batteries: NiMH batteries are a newer type of battery that have replaced NiCad batteries in many RC cars. They have a higher energy density than NiCad batteries and are also more environmentally friendly. They are also relatively lightweight, which can improve the car's performance and handling.

3. Lithium-Ion (Li-Ion) batteries: Li-Ion batteries are another newer type of battery that have become popular in RC cars. They have a very high energy density and are also lightweight, which can provide a lot of power in a small package. They also have a longer lifespan than NiCad or NiMH batteries.

4. Lithium Polymer (LiPo) batteries: LiPo batteries are a type of Lithium-ion batteries which are similar to Li-Ion batteries in terms of energy density, but they have a flexible polymer material instead of a metal casing. They are lightweight and offer high discharge rate, making them perfect for high-performance RC cars. However, LiPo batteries require special handling and charging procedures to avoid any safety risks.

5. Lead-Acid batteries: Lead-Acid batteries are known for their reliability and are often used in larger RC cars such as RC boats or planes. They are relatively heavy and bulky, but they can provide a lot of power for a long period of time.

In summary, the main difference between the different types of RC car batteries is their energy density, weight, lifespan, and safety concerns. Nickel-Cadmium (NiCad) batteries are durable and reliable, but have a relatively low energy density and are heavy. Nickel-Metal Hydride (NiMH) batteries have a higher energy density and are more environmentally friendly, but have a shorter lifespan than Li-Ion or LiPo batteries. Lithium-Ion (Li-Ion) and Lithium Polymer (LiPo) batteries have a very high energy density and are lightweight, but require special handling and charging procedures. Lead-Acid batteries are known for their reliability but are relatively heavy and bulky. The choice of battery will depend on the specific requirements of the RC car and the type of usage.