In this article, we are going to discuss some of the batteries that are suited for the FrSky X9d transmitter and at the same time, available in the market to buy. The battery is substantially an important part of RC Hobby. We cannot think about a world without battery and RC Hobby won't even exist if that was the case. But, our technology has advanced and the branch of battery technology has progressed more than we can ever think of. There are different types of batteries available that are unique from each other in terms of storage power, durability, performance, stability, etc. 

When I say we are going to discuss batteries, it doesn’t mean we are going deeper into the science behind it. Rather, we are going to compare each one to see how it dominates over the other one in terms of the various aspects and attributes related to it. Moreover, this is the beginning of the series of articles which is generally an introduction into various types of batteries after which we will be listing some of the best batteries available for FrSky X9d Transmitter as well as the other Taranis and Horus radios.


The battery is a device that consists of one or more electrochemical cells with external connections that convert chemical energy to electrical energy for powering electrical devices like radios, clock, etc. As you know, there are two types of batteries; Rechargeable and non-rechargeable batteries. Rechargeable batteries that are also known as secondary cells that have the capability of reversible cell reactions that allow them to regain or recharge their cell electric potential as the result of work done when a reverse current is passed through it.

So this article is supposed to give you an insight into different kinds of rechargeable batteries that are available in the market, discussing their pros and cons and giving some tips as well. In the upcoming articles, we will review and list some of these batteries that are suited for the FrSky x9d transmitter which is available in the market. So let's get started


Li-ion Batteries

There are many Lithium batteries like Li-ion, Li-po, Li-fe, etc. that are entirely different when compared. The distinction between these batteries lies in the electrolyte used in it. Li-ion battery uses Lithium cobalt oxide as the cathode. Li-ion batteries are very popular ever since because of their energy density which is higher than all the other lithium batteries.

But at the same time, these batteries are considered dangerous because they can cause combustion. Li-ion packs a crazy amount of energy in the small size factor, but can easily cause a fire since they are unstable. Perhaps sacrifice is the reason they contain tons of energy? Well, I leave that question for you.

If the barrier that separates the negative and positive electrodes is breached, it can lead to a series of chemical reactions that will result in combustion. For the same reason, proper care should be taken. Don’t get afraid that your FrSky x9d transmitter gets on fire. Li-ion is safe as long as you take care of it properly.

These batteries don’t have memory effect which is found in some other batteries like Ni-MH. We will explain the memory effect while explaining the Ni-MH batteries. Moreover, the Li-on battery is subjected to aging. Although a typical li-ion battery can go through 300 to 500 recharge cycles, they will suffer from aging which means after a certain period, they will gradually tend to lose their potential energy storage capacity. So, even if you don’t use the battery after purchasing it, it will be garbage after  2 or 3 years.



  • High Energy Density in small size factor
  • No Memory effect
  • Lower cost
  • Higher Number of Recharge cycles


  • Risk of causing fire
  • Highly Inflammable
  • Sensitive to temperatures
  • Very short Lifespan
  • Unstable

We have briefly covered some of the aspects of Li-ion batteries in general and how they dominate from other kinds of batteries under different circumstances. You may think about leaning towards Li-ion for FrSky x9d transmitter because of its high energy density factor, but need to understand that they are dangerous if not taken care properly. But they have a short lifespan, on the other hand, Lipo and other batteries are safer and have a long lifespan.

We will be discussing Li-Po batteries in general in the upcoming article on which I think about comparing Li-ion with Lipo and I believe that will give you an insight into how Li-Po dominates over Li-Ion in some aspects.

I hope this article has helped someone to understand some attributes related to the li-ion batteries for choosing a battery for FrSky X9d Transmitter. But this isn’t ending here, we will be covering Li-Po, Li-fe, and Ni-MH batteries in the next article. Stay Tuned!