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We probably all know batteries are a huge part of the RC world since most RC cars are battery powered. Whether you are a new racer or an advanced racer, you probably already know that electric RC cars can only work with batteries or battery packs. Now, everyone wants to have that RC car that can last for as long as possible while they race and play with their RC vehicle so that is where this article comes in.
When it comes to electric cars, the run-time depends on the type of battery you use, the age of the battery, how well it is taken care of, and how hard you drive the RC car. Each of these will have an effect on how long your RC battery will last you before needing recharged.
There are different types of battery used in electric RC cars. The rechargeable batteries are nickel-metal-hydride (NiMH), nickel-cadmium (NiCd), lithium-polymer (LiPO), and lithium-ion (Li-ion). Alkaline batteries are also a good idea seeing as they last longer. However, the disadvantage of alkaline batteries is that they have a very low power output, which can slow down the movement and response of the car. NiCd and NiMh are the more commonly used types of batteries because they’re not only economical but also practical.
A standard 7.2v RC electric car battery pack has a measurement of 130mm x 45mm. The MaH shows the battery’s capacity, and what this means is that the more the MaH, the longer the battery will last. Also, keep in mind that with more capacity comes more cost. The run-time of a battery can also be affected by the surface it’s driven on, how it’s driven, and the power used by the engine.
A lot of batteries for electric RC cars are designed to last for a minimum of 5 minutes with more expensive models lasting for 30-45 minutes before needing to be charged. A large percentage of RC cars come with a battery of 7.2 volts and an 1800 MaH or more capacity.
Speaking of charging the battery, a lot of factors may determine how long it should be charged. Just make sure not to overcharge, so you do not damage them. It’s safe to unplug your batteries once they have begun to get warm (not hot) from the charging.
Now, let’s look more closely at the types of batteries we have already mentioned.
Types of batteries
Voltage and cell counts are different among the Lithium batteries, the NiCd, and the NiMh. Compared to conventional NiCad or NiMH battery cells that come with a voltage of 1.2 volts per cell, Lithium battery cells have 3.7 volts per cell. Each type of battery displays a different action when charging and discharging.
Lithium batteries have been charged fully when there’s a voltage of 4.2 volts per cell. And when they have a voltage of 3.0 volts per cell, they have been completely discharged. It is very important that you don’t exceed both the high voltage limit and the low voltage limit because this can spoil the battery.
LiPo gives a very linear power output, and when the voltage drops, the power also experiences a sudden drop, which means you can no longer use the engine. Very lightweight, the Lithium batteries have big capacities and can power even highly demanding electric motors with their high discharge rates. But the benefits that LiPo batteries offer also have disadvantages, especially when it comes to charging and discharging. Lithium cells have to be charged separately from NiCd and NiMh, and the riskiest thing about Lithium batteries is this part of charging the cells.
LiPos are also more prone to exploding because of the volatile electrolyte used in them. Make sure you set your charger to the right cell count or voltage to prevent danger. Be extremely careful and take safety precautions to ensure you don’t have any issues.
If you want your LiPo to last a long time, you need to care for it and keep in mind that RC LiPo batteries require unique and proper care, and the charging, discharging, and storage can affect its lifespan.
Charging your batteries
Always use a safe surface to charge your batteries so that in the case of an explosion, no damage will be caused. Also, never charge the batteries unattended. Vented fire safes, plant pots with soil, and LiPo Sacks are things you can use. If you’re charging a cell and it swells, put it in a fire-safe place and do not attempt to puncture or deflate it.
How fast the battery can be safely discharged is what is called the discharge rate. In the world of LiPo batteries, it is referred to as the “C” rating. If a battery has a discharge rating of 1 C, it means you can safely discharge it in 1 hour, and 2 C would mean you can safely discharge in half an hour. Batteries with capacities are rated in milliAmp-hours (mAh), so it would be nice to understand the idea of Watts, Volts, and Amps.
Another nice way to check if you’re using a C-rating that is high enough is by having a temperature reading of your packs after running them is. A handheld Infrared Temperature Gauge (such as this one) could perfectly do the job. To get the best battery life, prevent your cells from getting to 160 degrees Fahrenheit after use and protect them from the cold, especially during the winter.
Also, RC battery chargers are one of the most important things for an electric RC owner. With so many battery chargers on the market, here are the three most popular for you to consider:
Slow Charger: It is cheaper and typically outputs about 150 mAh, plus it takes longer to charge. Even when the battery is fully charged, it won’t automatically turn off.
Fast Charger: This outputs up to 5 amps and charges for a lesser amount of time. When the cells are fully charged, it automatically shuts down.
Field Charger: This one is very convenient, and you can charge your batteries anywhere you are. Just clip the alligator clamps to any 12-volt battery and charge.
Lithium batteries may require a whole different kind of charger. Emphasize the fact that you use Lithium batteries and look out for which battery charger would suit you best. Also, put their advantages and disadvantages into consideration to help you make a good choice.
As you can tell RC batteries are not exactly simple so knowing exactly how long one will last is quite difficult. For most people and in most situations RC batteries will last 30-45 minutes but that can vary a lot from car to car and battery to battery.
A battery that is designed to move your car much faster will normally not last as long as one that is designed for your car to go a bit slower for longer periods of time. RC cars that go 200MPH (yes there are those) will not have batteries that last as long as an RC car that goes 50MPH simply because of the power needed to reach those much faster speeds.