Although there are high end drones that are powered by fuel, chances are yours will be powered by battery. There are other battery types available, such as NiCad’s and NiMH’s, but in this article we will focus on the use and care of the LiPo battery.
What is a LiPo Battery?
Lithium polymer batteries (LiPo) are rechargeable batteries using lithium-ion technology and are often contained in a soft pouch. They are also very popular in the RC field and are a good choice of battery to power your drone.
The lithium-ion technology allows the battery to have a very high energy density as compared to other types of batteries. Since the battery has a high energy density, yet weighs the same as other batteries, which makes them a popular choice for powering RC vehicles.
When looking at different LiPo batteries, you’ll see numbers for various specifications. To help you understand the differences between these batteries, we’ll take a closer look at what these numbers mean.
A battery is constructed from interconnecting individual cells, each cell consisting of some metal and chemicals that are able to generate an electrical charge. Each cell, which is technically a battery of its own, holds a small charge of 3.7V. So, a battery with two cells would hold 7.4V, three cells would hold 11.1V, and so on. The cells in the battery may be connected in series or parallel. For example, a battery that is labeled as 2S2P would indicate that it has two cells connected in series and two cell sets connected in parallel to double the capacity for a total of four cells.
The voltage for an individual cell is 3.7V, but that will drop as the battery is used. The operating range of a 3.7V battery is between 3V and 4.2V. Which means you should not allow the battery to go below 3V of power when operating or let it go above 4.2V while charging. Operating the battery outside of its range can damage the battery.
The capacity of a battery is the measure in mili Amp hours (mAH) as to how long it can provide energy –the higher the rating, the longer the amount of time. A drawback is that the higher the rating, the heavier the battery.
Another important specification is the battery’s discharge rate. The discharge rate is how fast a battery can be discharged safely, which is called its C rating. A battery with a 10C rating would allow for the battery to be discharged at a rate ten times that of its capacity. The higher the C rating is, the better and the more expensive the battery. A typical rating for your drone’s battery would be a 25C to 30C.
The number one killer of LiPo batteries is overcharging and drawing its power below the 3V per cell a close second. A good rule of thumb is to never discharge a battery more than 80 percent of its capacity. For example, if you have a 2000 mAh LiPo pack, you should never draw more than 1600 mAh from the battery. An inexpensive LiPo battery monitor is an easy way to monitor your battery usage.
Selecting the correct LiPo battery to power your drone is an important step and now that you understand the technical specifications of LiPo batteries, you should now be able to select the right battery for your drone.