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Do LiPo Batteries Make RC Cars Faster?

If you are searching for ways on how to improve the performance of your RC car, then you should make sure the vehicle is getting the power it requires. Even if you are an expert you often don’t need to just go and upgrade your motor and ESC. If you ignore upgrading your battery, then you  might be missing out on an easy way to increase the power and speed of your RC vehicle. 

If you are still using old school NiMH rechargeable batteries, you might get surprised when you change to LiPo. Whether you operate an RC buggy, on-road race car, or truck, for sure, you should notice a big difference with LiPo batteries. 

If you upgrade from a NiMH or NiCD battery to a LiPo you will almost assuredly notice an increase in the acceleration and top speed of your RC car. Even if you just upgrade from an older LiPo to a newer one you will still probably see a significant increase in the speed of your RC car. 

When changing types of batteries you do need to make sure that the new battery you install is compatible with your model so be sure and read the owner’s manual so you don’t damage your vehicle with the extra power. 

You can check out the video below to learn more about upgrading your RC car’s battery. 

Before we talk more about the pros and cons of LiPo batteries we first want to mention what exactly a LiPo battery is. 

So what is a LiPo battery

Generally abbreviated as LiPo or Lipoly, the full name is a lithium-ion polymer battery. These batteries always come in either a soft weight-saving pouch or in a hard plastic case.

Every cell has a nominal voltage of 3.3 – 3.7v against traditional cylindrical Ni-cads with a voltage of around 1.2v – 1.5v. That’s why Li-Po battery packs have unusual voltages, 3.7V 1 cell, 7.4v, and 11.1v, etc., compared to Ni-cads with 1.2v per cell and typical six-cell RC Ni-cad or Ni-MH pack with 7.2v total voltage.

Use of LiPo in RC models

In the late nineties, LiPo batteries started to be used for a variety of RC cars and planes, and now they have virtually taken over the old Ni-cad or NiMH batteries on most higher end RCs.  LiPo’s small size, lower weight, and the extra power they provide have made them famous and they are being used in more and more devices.

The pros of LiPo batteries in RC cars

  • LiPo’s are  lightweight. When your car has less weight, it means a faster car with better acceleration.
  • Much more power from the same battery size.
  • More punch due to the large currents they can deliver.

The Cons

  • LiPo batteries require more care when charging, you should never leave them unattended while on the charger, and they should be placed outside in a garage or shed. It doesn’t matter where you charge them, but they should always be charged in a fireproof container. It rare for these batteries to catch fire, but if they are abused, it’s easy.
  • These batteries need a LiPo compatible battery charger, although many modern digital chargers support them and other battery types as well.
  • LiPo batteries shouldn’t be run until completely drained as it will more than likely destroy the pack, and you may not be able to get a charge back into it. Even if most ESCs will have a cutout feature to prevent over-discharging, it’s better to keep a record of your run times so that you know the right time to stop using your pack to avoid damaging it.

Store LiPo batteries at 50%

Whenever you are storing your battery for an extended period, it’s recommended you partially discharge it and keep it in a cool place. Most LiPo balance chargers have a storage preset which will discharge or charge the battery to the correct level to extend its life. For instance, a 2s 7.4v battery storage charge might be 7.6v. Use a battery checker to find out the voltage. A fully charged LiPo typically has around 4.2v per cell. Battery manufacturers say they should not be charged below 3.3v per cell. That is why most ESCs have an automatic cut out feature set to this value.

Charging safety 

  • You should never leave a battery unattended while charging.

You can still be doing other things like watching TV or anything else but you shouldn’t leave the room or the house when the battery is charging. 99.999% of the time, batteries charge without a hitch. But if you are in the 0.0001%, being by the charger is what will prevent damage to your RC gear and other property.

  • Use the right charger.

Never use the NIMH charger to charge Li-Po batteries. This is because Li-Po cells tend to catch fire if you try it. You should only use a Li-Po charger when charging Li-Po batteries. There are some chargers (such as this one) that are designed to be used with all types of batteries so those chargers are fine to use on both types. 

  • Use the right connectors

If your charger and batteries have a different type of connector, you should buy the appropriate adapter or install the matching connector. Never jerry-rig connections with exposed wires or clips, as these may damage your charger, battery, or even start a fire, which will obviously result in extra cost.

Li-Po balancing

When buying a Li-Po charger, make sure it can balance the cells in the pack as it charges. The balanced load means the cell’s voltage is kept the same. For instance, a 2 –battery, the 7.4-volt box, is stable if both cells have 3.7 volts. If you fail to balance the cells, their voltages may drift apart after a few charge/discharge cycles. This matters because LiPo cells don’t tolerate being overcharged well.

And while your speed control’s low voltage, the detection system will prevent the pack’s total voltage from dropping past the exact point, for example, 3.3 volts per cell, or 6.6 volts for a two cell pack, the speed control only sees the full voltage of the battery, not the voltage per cell. In case the battery pack is not balanced, that 6.6 volts might not represent 3.3 volts per cell. One cell could be 3.6 volts and the other one 3 volts. That cell will be overcharged, and your pack is compromised. Balanced cells have equal voltage. 

Caring for Li-Po batteries

Taking good care of your batteries contributes to maintaining the performance and getting the maximum service life of the battery. How you use and store your batteries matters a lot. 

Here are a few rules to follow

Use low voltage detection. The detection alerts you when your car needs to be recharged. If you ignore it, you will run the risk of over-discharging the battery. Hence the performance and the life span of the battery will be reduced.

Keep your batteries clean. This applies to all cells. If you fail to clean your batteries, you are inviting further damage and short circuits.

Conclusion

Li-Po batteries are the best option when it comes to making your RC car faster. They are very light and can be charged many times a day as needed. You should always follow the manufacturer’s instructions when charging and storing but in general Li-Po batteries are much better than their NiMH counterpart and will certainly get you better acceleration and speeds.