There are so many LiPo batteries packs in the market. Which one should you get for your FPV drone? Here’s my pick of the best LiPo battery for FPV drones, and things that you need to know when choosing your LiPo packs.
Best LiPo Battery 2023
CNHL Black
I’d say the CNHL Black falls under the bang for buck category. It’s not the cheapest, but it is certainly affordable, especially since you will need a lot of LiPo batteries. In terms of quality, many people swear by it. In fact, it ranked 2nd in the 2020 Drone Racing International FPV freestyle go-to battery poll.
Tattu R-Line
The Tattu R-Line is specifically designed for racing. It has high capacity, low internal resistance and it is lightweight. There is one disadvantage though… it’s rather expensive. Use this in your race event to shave some weight off your drone. It can make a difference!
Thunder Power Steele Davis Lunar Landar Edition
This battery is even more expensive than Tattu R-Line! What makes it so special is its unbelievable weight. It weighs only 176 g for 1100 mAh capacity. Equivalent CNHL Black weighs more than 200 g!
If you are looking at shedding more weights, consider getting this battery!
Types of Batteries for FPV Drones
When looking for FPV drone batteries, you’ll encounter 3 main types of batteries that might be suitable for your drone. They are LiPo, LiHV, and Li-Ion batteries.
In short, LiPo battery pack is the preferred battery for racing and freestyle FPV drones that require strong burst for a short duration, while Li-Ion is suitable for long range cruising and long flight time. If you are joining a tournament, switching to LiHV can give you an extra boost.
LiPo
LiPo stands for lithium polymer. A standard LiPo cell that is used in racing or freestyle FPV drones has a fully charged voltage of 4.2 V with a resting voltage of 3.7 V. When it comes to performance, LiPo batteries are more consistent and more commonly used.
LiHV
LiHV means lithium polymer high voltage. A standard LiHV battery pack has a voltage of 4.35 V at full charge and a resting voltage of 3.8 V.
The extra voltage provides additional power to the motors which makes your drone fly faster. This makes it an ideal choice for those who want a boost in a drone race. Moreover, LiHV has a larger capacity which translates to longer runtime, a lower voltage sag, and it is generally safer than LiPo.
Having said that, most pilots still prefer LiPo over LiHV because the degradation of LiHV performance seems to be significantly faster than that of LiPo. But if you are going for a tournament, you should consider swapping to LiHV for the extra power.
Li-Ion
Lithium ion batteries typically have a much higher capacity compared to LiPo of the same weight. It is also cheaper and safer than LiPo.
Because of its high capacity, Li-Ion batteries are good for long range FPV, since flight time is crucial in long range cruising.
However, Li-Ion battery has its own weakness.
For one, it doesn’t support high discharge rate unlike the LiPo battery. That means it can’t support your drone in making excessive acceleration or deceleration or sudden turns like what LiPo or LiHV does. Forcing your Li-Ion batteries to do so will only destroy it. Hence, you wouldn’t want to use Li-Ion batteries for racing.
Do check out my guide on how to fly long range FPV.
How to Choose LiPo Battery Packs?
Use a 4S LiPo pack for drones of 2.5” or above and 6S for 5” drones. Find out the minimum capacity to achieve the desired flight time. Calculate the minimum C rating of your LiPo battery, and prioritize one with higher energy density. Buying LiPo batteries of a reliable brand can reduce the risk of fire and explosion.
Battery Voltage and Cells
The main two things that you need to look for when it comes to battery specifications are the battery voltage and the battery cells.
Battery voltage determines the power of your drone. Having a higher battery voltage will allow your drone to have more power without needing to increase your amp draw or current. In turn, that power will determine the RPM of your drone motors.
In FPV drone racing or freestyle, you would want your drone to be a high-powered one to achieve great speeds.
However, you can’t reach high speeds with only a single cell battery. This is where battery packs with multiple cells come in.
Let’s take a standard LiPo battery, for example. A LiPo cell has a full voltage of 4.2 V. To increase that voltage, cells are connected together to form a chain. The higher the number of cells grouped together, the higher the voltage is.
Battery packs are normally grouped in 1S, 2S, 3S, 4S, 5S, and 6S configurations. The number equates to how many cells are linked together. For instance, a 5S LiPo battery pack can hold up to 21 V (5 x 4.2 V) at full charge.
In short, the higher the cell count, the higher the voltage, and subsequently the higher the RPM of your drone. This does come with a price though – in the form of additional weight and cost.
You need to balance power and weight so that you can achieve a desirable speed. Most pilots nowadays use 4S batteries in their builds for anything 2.5” and above. For 5” build, it is better to use 6S instead.
Battery Capacity (mAh)
Each battery has its own capacity, measured in mAh or milliamp hour. If a battery has a 1000 mAh, it simply means that it can supply 1000 mA for an hour. The bigger the capacity, the longer the flight time the battery can provide per charge.
However, bigger battery capacity is not always better. A bigger capacity means a heavier battery which might not be optimal for drone racing.
For drone pilots, it sure is convenient when you don’t need to constantly recharge or replace your battery packs in the middle of a flying session. But are you ready to fly slower than your foes? Probably not. Even if you are flying freestyle, it is harder to pull off tricks with a heavier drone.
On the other hand, small capacity batteries might not be enough to power up your drone long enough to complete a heat.
Similar to voltage, you need to balance the capacity/flight time with speed. In race events, pilots typically use 1300-1500 mAh batteries.
Flight Time
A long enough flight time is what you want from the battery. While it is not easy to calculate the actual flight time accurately, a reliable estimation is a good reference point to start with.
You can use an online calculator to estimate your flight time. There are a few different calculators using different formulas. I personally use this calculator. It requires some basic information on your battery, motor, and the weight of your drone. Some of the data (eg. efficiency, amp draw) can be obtained from miniquadtestbench.com or the manufacturer.
Remember to read the guide before using the calculator. And be careful on the unit of measurement (eg. efficiency) when inputting the data into the calculator.
Do note that flight time is heavily dependent on your flying style. In drone racing, typical flight time per charge would be lesser than 5 minutes, or probably 2-3 minutes in a higher level race.
If you want to maximize your flight time, consider using Li-Ion batteries instead. Li-Ion batteries typically have much higher capacity than the LiPo at the expense of the discharge rate.
C Rating
C rating is also known as the discharge rate. It is typically shown as a number followed by “C” on the battery pack. It basically tells you how fast you can safely charge or discharge your battery. The higher the number, the higher the discharge rate.
At a higher throttle, the battery needs to discharge faster to provide enough power to your drone. While all batteries can discharge faster, you need a battery with a high C rating to safely do that. In racing or freestyle drone, you will likely need batteries with a C rating of at least 75. Do note that batteries with higher C rating are slightly heavier than their counterparts with lower C rating.
A higher discharge rate translates to higher maximum amp draw, as described in the following formula:
Max amp draw = battery capacity x C rating
Assume your battery has a capacity of 1300 mAh. If you discharge it at 1 C, your battery provides 1300 mA for 1 hour; if you discharge it at 2 C, your battery provides 2600 mA for 30 minute; if you discharge it at 60 C, it provides 78000 mA for 1 minute.
You need the max amp draw of your battery to be higher than your motor’s max amp draw. Let’s say your motor draws 30 A at full throttle. Since you have 4 motors, the total amp draw is 120 A. Working backward, if your battery has 1300 mAh capacity, the minimum C rating you should get is:
120 A divided by 1.3 Ah (1 A = 1000 mA) = 92 C.
Always buy your LiPo batteries from a reputable manufacturer because many manufacturers tend to over report their battery C rating for marketing purposes.
Charge Rate
Charge rate is the rate at which the LiPo battery pack can be charged. LiPo batteries with a higher charge rate can be safely charged at a faster speed. The typical charge rate of LiPo batteries is between 1 to 3. Charging at a rate higher than the recommended charge rate can damage the LiPo and cause fire.
To find out the current used at different charge rate, simply multiply the charge rate with the battery capacity. For instance, A 1000 mAh LiPo charged at 1 C is charged at 1000 mA, 2000 mA if it is charged at 2 C, and 500 mA if it is charged at 0.5 C.
Battery Energy Density
One metric that you can use in evaluating the batteries is by looking at the energy density. In this case we are looking at the amount of energy stored per gram of battery. The higher the energy density, the better is the battery because it is lighter in weight vs other batteries that have the same capacity.
To calculate energy density, multiply the capacity with voltage and divide it by the weight. For instance, a 1350 mAh 6S battery weighing 260 g has an energy density of 0.13 Wh/g (1.35 Ah x 25.2 V / 260 g).
Brand
It might not be obvious, but certain brands do produce better batteries than others, even if they have the same published specs. That’s because some manufacturers may measure certain specs using different methods or parameters. Some of the top brands include Tattu, Lumenier, just to name a few.
On top of that, there are some specs that are not apparent to the users. One of which is the aging factor. That means, how many charging cycle does it take for a battery to show significant drop in performance. A good battery can last you for a few hundred charging cycles, while a cheap battery might require replacement a lot faster.
Another reason to choose your LiPo battery from a reliable brand is due to safety. LiPo battery packs are inherently dangerous. A reliable LiPo will greatly reduce the risk of fire, which to me, is important.
Final Words
As drones gain popularity, there are a variety of battery packs with different specs in the market, which makes choosing the right battery daunting. However, it is not as difficult as you thought. Knowing what to look at and the reasons behind that would make it straightforward in deciding your choice.
Remember to check out my guide to learn how to safely manage LiPo batteries and how to choose a suitable charger for your LiPo.
Additional Information
Voltage Sag
Voltage sag is a phenomenon where the battery voltage drops at a faster rating at higher throttle. As you release the throttle or switch to a lower throttle, the voltage recovers.
Voltage sag is more apparent in batteries with a lower C rating and lower cell count, where the voltage drop is higher and the recovery time is longer. Batteries from an unreliable manufacturer would have the similar issue.
This makes managing LiPo discharging harder and puts your battery at higher risk of damage because the voltage easily drops below the minimum recommendation.
Hence, it is always recommended to get a battery with a higher C rating and cell count from a reputable manufacturer.
