The Electronics of Airsoft: Part 2: Batteries
One of the greatest marketing schemes in Airsoft is when distributors claim that such-and-such gun is “LiPo ready.” This phrase is such a joke, especially considering that most of the time the distributors only mean that it has a “reinforced” (whatever that means) gearbox or some such nonsense. Don’t be fooled by people trying to sell you something claiming it can stand up to LiPo batteries. Understand that the concept that “LiPo ready” emphasizes does exist, but that it is not what most people think. Today I will give you a rundown of all batteries in Airsoft, and how each type differs from the others, all leading up to what it takes to make your replica “LiPo ready.”
There is quite a variety of battery types and specifications in the hobby world. Though the batteries used in Airsoft are slightly more specific, those used in hobbies such as RC cars and planes or drones are vast and varied beyond immediate recognition. It is common for an Airsoft beginner to look at the market for batteries and become completely overwhelmed. They usually end up buying the wrong battery for their setup. My hope is that this post will clear up some confusion about Airsoft batteries in general.
I know this has been done before, and you can find all of this information elsewhere on the web, but my plan is to make a comprehensive library of airsoft information through my posts here in Slingin Plastic that covers every topic. I will be quite detailed, and cover many different sources-worth of information in one post.
I would like to start with a little overview of some general electronics, just to establish a base of understanding for what I will be covering in this post.
When working with electronics in airsoft, it never hurts to have a basic knowledge of how electricity works. I will go over exactly what Volts and Amps are in a later part of this series, but for now I want to cover how those things relate to batteries and the gearbox.
In general, the higher the voltage (of a battery) the faster the motor will spin. Also, in general, the more difficult it is for the gearbox to turn over, the higher the amperage that will be drawn from the battery.
For all batteries, more cells (each individual part of a battery) means more voltage. That is why batteries can only be found in certain voltages, such as 8.4, 9.6, and 11.1. Different kinds of battery cells have different “nominal voltages,” or the voltage the battery is meant to sit at. NiMH and NiCad batteries come in multiples of 1.2V per cell, and LiPo batteries come in multiples of 3.7V per cell.
A MOTOR, GIVEN A CERTAIN VOLTAGE, WILL TRY TO SPIN AT A CERTAIN SPEED.
That is the basis for all motors. The higher the voltage, the higher the speed you will get, and therefore more rounds per second fired. Due to differences in the chemical ability to release stored power, or amperage, some types of batteries are MORE CAPABLE of giving the required power (amperage) to let the motor achieve said certain speed, which is why we see the big difference in power between some batteries.
Note, for people who might have knowledge of electricity already: For the sake of this post, when I use the word “power” I will be referring to the amperage the battery supplies. Even though this is incorrect terminology (“Power” has its own specific meaning), I feel it is okay to use the word in this situation, especially because when I use it, I am not generally referring to voltage, so we can assume it is not changing.
Now, on to the different types of Batteries you may come across.
Nickel batteries:
Let’s start with the oldest battery used in the hobby. Nickel-Cadmium, or NiCd batteries used to be the standard in the Airsoft world. While some few replicas may still come shipped with a NiCd, their large size and specific usage instructions have made them widely ignored by the Airsoft community.
NiCad batteries are capable of putting out a slightly higher power than their NiMH counterparts, but they must be completely discharged before recharging to avoid rapid breakdown of the cells due to improper balancing. If that doesn’t make sense to you, stay tuned for a bit more of an explanation.
Next we have the most common batteries in the Airsoft world today: Nickel-Metal-Hydride. These batteries are everything NiCad batteries are and more. Coming in at a slightly lower power output compared to a NiCad, a NiMH battery is advantageous in nearly every other way. Most new Airsoft guns that come with a battery come with a NiMH, and they are good for nearly every situation for entry-level and even mid-level players (see Getting Started with Airsoft, Part 1 for more on that).
NiMH batteries can be recharged at any time, and at any amperage low enough to not fry the cells (below 2A, usually). They are nearly half the size of a NiCad of the same voltage, and usually cheaper to buy. They are less likely to break down, and can give good output for many years if maintained properly. An all-around GOOD battery for Airsoft, as long as your are not looking for high rate of fire.
Lithium Batteries:
The great debate for Airsoft batteries is centered around the next battery I will cover: LiPo, or Lithium-Ion Polymer. These batteries are not only smaller than a NiMH, but also are capable of putting out insane amounts of energy for long periods of time. If care is taken to ensure your LiPo batteries are properly charged, they will perform well under nearly any circumstance.
In my opinion, every Airsoft player should know how a LiPo battery compares to other batteries, and how to properly charge and maintain them. Lithium-Ion Polymer batteries are similar to the batteries we find in common electronics, such as cell phones or tablets. Compared to other batteries, they trade a little bit of stability for a whole lot of power. A 7.4V LiPo battery can make an Airsoft gun shoot the same speed or faster when compared to a 9.6V NiMH. Yes, I said the lower voltage LiPo shoots Faster.
This power difference is why it is such a common thing to ask “is my gun LiPo ready?” If you go and plug an 11.1V LiPo into a stock entry-level AEG, chances are you are going to break something. If you tune said AEG, however, and put in the hours and the $20 or so worth of parts to make sure everything is aligned the way it should be, the replica will probably be fine. I’ll get more in depth on what makes a gun “LiPo” ready later, but for now, just know that LiPo’s are powerful. Very powerful.
I might as well mention LiFe, because I feel that they may become more popular in the coming years. Lithium-Ferum or Lithium-Iron-Polymer batteries are not yet popularized in the Airsoft world. They are a bit more pricey than a LiPo, but not enough to break the bank. The key difference between LiPo and LiFe is stability. While LiPo batteries have been known to burst into flames when improperly charged, LiFe batteries are much more forgiving.
They come in different voltages, but can put out just as much power as a LiPo. They are a bit larger and heavier for the same capacity, but more capable of dealing with the amperage required by an Airsoft motor. They require the same charging considerations, but are much less likely to catch fire or break down if abused.
A quick note on C-Rating:
So what is it that makes Lithium batteries more powerful? Why does a lithium battery with 20% less voltage provide just as much or more speed as a nickel battery? You may remember from my earlier explanation of batteries in general that voltage is not all there is. The answer lies in the current, what I have been calling "power." The ability to discharge is measured by what we call C-rating.
A given motor will “try” to reach a certain speed for a given voltage, regardless of where that voltage is coming from. What limits the speed provided by a battery is that battery’s chemical ability to release the electrons it has stored. LiPo Batteries have the capability to discharge a heck of a lot more energy, and the motor gobbles it up to reach its speed as quickly as possible, and to maintain that speed. This has its own set of considerations, but I will cover C-rating and such in detail later on in the series.
There are a few more things to know about batteries and the gearbox, but hopefully this gives you a good idea of what is available out there. Be sure to read the next few posts about The Electronics of Airsoft to get a better idea of How to Choose a Battery and what it means to be LiPo Ready.
Thank you all!