RC Car Batteries

Posted by RC Masters on 15th Jan 2013

In the RC industry, fuel and batteries play a significant role in running the RC technology. We know how important batteries are, whether electric or nitro you would simply need batteries or battery packs for the electric unit and its controller. Traditionally, RC cars have been powered by Nimh battery packs. But recent technological advancements paved the way to the evolution of more efficient cells. This would be the read you need in choosing the best batteries for your RC models.

Batteries for electric rc can come in alkaline or rechargeable type. Alkaline batteries have a common downside when it comes to power output. 

The various types of rechargeable batteries are:

  • Nickel-cadmium (Nicd)
  • Nickel-metal-hydride (Nimh)
  • Lithium-ion (Li-ion)
  • Lithium-polymer (Lipo)

    These options are essentially practical and economical. All you need is a charger and it saves you from buying new set of alkaline batteries when they wear out. If you’re eyeing for longer runtime, you may want a bigger Mah rating but this will generally cost more.

    A standard 7.2v RC electric car battery pack measures at 130mm x 45mm. The Mah indicates the capacity of the battery. So, the greater the Mah, the longer it will last. Majority of RC cars come with a battery that has 7.2 volts and a capacity of 1800 MaH or greater. The regular rechargeable battery pack typically provides approx 10 minutes of drive time at full speed between charges.

    Be careful in using batteries with seemingly higher voltage. Make sure to check first with the manufacturer if the motor and ESC can handle the extra power.

    Now, how do you opt for the best batteries? Here’s a detailed drill to find the best deal.

    Voltage and cell counts differ amongst the Lithium batteries and NiCd and NiMh. Unlike conventional NiCad or NiMH battery cells that have a voltage of 1.2 volts per cell, Lithium battery cells are rated at 3.7 volts per cell.

    Lithium batteries have been a hot ticket in the RC world since it was introduced. Lithium-ion and Lithium-polymer may be similar in voltage counts but distinct in other ways. Li-ion batteries have high energy-densities and cost less than Lipo cells. More so, they do not require priming when first used and have a low self-discharge. However, Li-ion batteries do suffer from aging even when not in use. The chemical construction of this battery limits it to a rectangular shape. It’s lighter than nickel-based secondary batteries (Ni-Cd and NiMH) and generally twice its capacity.

    Lipo batteries are very lightweight with its very thin designs but still holding relatively good battery life. This is the latest upgrade to battery technology. It also provides a very direct output however, these batteries will cost more to manufacture and have a not so good energy density than Li-ion batteries.

    When it comes to charging and discharging, each type exhibits a different action. Lithium batteries are fully charged when each cell has a voltage of 4.2 volts. They are discharged completely at 3.0 volts on each cell. It is vital that you do not exceed both the high and low voltage limits as this may damage the battery.

    Charging cells is the most risky part of using Lithium batteries. Since it is highly explosive due to the volatile electrolyte used in Lipo, they can easily catch fire. It is important to set your charger to the correct voltage or cell count to avoid any untoward incidents and make sure you don’t leave them unattended.

    Discharge rate is simply how fast the battery can be discharged safely. In the RC LiPo battery world it is called the “C” rating. A battery with a discharge rating of 1 C would mean you could safely discharge it in 1 hour and 2 C would discharge it in half an hour. All batteries holding capacities are rated in milli Amp hours (Mah) so any insight and knowledge about the concept of Watts, Volts and Amps will be greatly convenient.

    Battery technology is a very active field of study. We are constantly looking for a much improved cell that can store more energy and recharge faster. I believe there will be innovations of this sort soon but for now try to evaluate the pros and cons to help you assess the best battery that will work for your beloved RC vehicle.