Batteries are the power sources for quadcopters, and different types of batteries such as LiPo, Li-ion, and LiHv are used in FPV. To properly charge these types of batteries, a specific charger is required. In this guide, we will focus on the best LiPo chargers that we have tried and tested.
A typical LiPo battery, on paper, should last for around 200 charge and discharge cycles. While a 1500mAh, 100C battery can theoretically provide 150A of current (the current capacity of a battery is calculated by battery mAh/1000 multiplied by the discharge of the battery), these batteries cannot be charged at the same rate as they are discharged.
Batteries are delicate components and can be flammable if mishandled, so it’s important to be careful when handling them. The battery’s behavior, discharge current, and life cycle depends on how the battery is treated. For example, mishandling a battery by charging it at high currents can negatively impact the battery’s performance. This guide will explore the top chargers for batteries and how to properly care for LiPo batteries.
Terminology
There are a few terms you must familiarise yourself with before diving into the guide.
mAh (milliamp hour) is a unit of measurement that denotes the capacity of a battery. It is similar to the battery capacity of a phone, where a larger number means a larger capacity. However, higher capacities come at the expense of increased weight.
A larger capacity battery will increase the overall weight of the quadcopter, which can make it feel slow and sluggish in the air. On the other hand, smaller battery capacities will result in a lighter quadcopter that feels more agile and nimble.
C rating: A C rating is a measurement of the amount of current a battery can safely deliver. A higher C rating means a higher discharge current. However, the C rating has become a number used for marketing and manufacturers often make false claims about these numbers.
Connector: A battery connector is present on the battery and helps connect it to the quadcopter’s flight controller and provide power to it. The type of battery connector present on the battery depends on the voltage and current carrying capacity of the battery.
A smaller battery typically uses a JST or JST PH 2.0 connector, while slightly larger batteries use XT30 and XT60 connectors. These connectors are designed to handle the specific voltage and current carrying capacity of the battery.
Parallel charging wires, also known as balance charging wires, allow batteries to be charged by connecting them in parallel. This is commonly used when connecting multiple smaller batteries in series to make a larger battery pack. The balance charging wires ensure that each individual battery is charged independently so that the overall battery pack is charged evenly.
Battery charging current – This probably is one of the most important factors and calculations to be made before charging a battery without damaging the battery itself.
As a general rule of thumb, a 1C charging rate is considered ideal. 2C charging rates are also fine, but anything higher might reduce the battery’s life in the long term. For example- A 1500mAh 100C battery can be safely charged at 1C (1.5A) or 2C (3A). Any advanced chargers have the option to change the charging currents depending on the battery itself.
Factors to consider
Some major factors differentiate a charger that will last you a long time and a charger that will work for a while and die. Let’s find out what those factors are, continue to read below.
Number of Charging ports
Charging ports are similar to our wall sockets where we plug in our chargers. Similar to this, we plug the batteries into our sockets aka FPV charger ports. FPV Chargers draw power from the wall and charge our batteries at a controlled rate.
Since not all batteries are the same, by different I mean different capacities, and voltages, they would need different charging needs. FPV chargers with 2 charging ports which are essentially 2 chargers, can do just that- charge dissimilar batteries.
But do you need 2 charging ports? Maybe. FPV chargers are things that don’t get replaced often and tend to stay with us for years and are just as critical as a Flight Controller to ensure the batteries don’t get stressed. Not only do dual charging port chargers are expensive than single charging port chargers, but they are also quite bulky. Single port chargers like the ISDT Q6 are so small that they can be slid into one’s pocket.
If the upfront cost matters to you, then you could pick a single port charger and use a parallel charging board, more on this below, and charge multiple batteries from the same charger.
Max Charging Current
Max charging current means the max current a charger can provide. A bigger battery requires a larger charging current. In the world of FPV, the most commonly used voltages are 4S and 6S. For a 1000mAh 6S battery, the typical charging current at 1C is 1A and at 2C is 2A, the same goes with 4s batteries. So we do not require a large max current rating if you charge a single battery at a time.
We can charge multiple batteries at a time if the charger has 2 charging ports, but most chargers come with a single charging port. There is another way to charge multiple batteries from this single charging port- Parallel charging boards. More on parallel charging boards below.
Battery Type Support
The most commonly used type of battery is LiPo (lithium polymer) battery. But we do use other kinds of batteries like LiHv (High Voltage LiPo), Li-ion (Lithium Ion), and some ancient batteries like NiMH (Nickel Metal Hydride) to power other peripherals such as FPV goggles and such. Some people even use Lead Acid batteries to charge batteries on the field.
If a charger only supports one type of battery chemistry, you really would be bound to that type of battery chemistry. If all your charger support is LiPo, then you would have to use LiPo batteries to power your miscellaneous. But the downside to using LiPo is the lower cycle count (The charge and discharge cycle) typically 200 compared to the 600 of the Li-ion batteries.
Portability
Some chargers like the ISDT Q6 weighing in at a mere 100g are so small that they fit into your pocket and some chargers like the SkyRC Q200 charger weigh at a not-so-light 1.3kg or just over 45 ounces. Portability matters when you have a small workspace or you plan to field charge your batteries.
But the Q6 (on the left) and the Q200 (on the right) are chargers of 2 different spectrums. The Q6 does not come with an integrated power supply, while the Q200 comes ready out of the box meaning to say it can be plugged into the wall socket out of the box with no need for external power supplies and other hassles.
Are you saving up space by buying a Q6? Probably not, as the size of the Q6 with a power supply comes to more or less the size of the Q200. But why buy a Q6? Because of the cost, while the SkyRC Q200 costs $175 the Q6 ($60) with the power supply ($24) comes to around $84 which is less than half of what the Q200 costs.
Max Voltage Support
Max voltage support is the maximum voltage that the charger can charge. Mostly we use a maximum of 6s batteries i.e. 22.2V. Most professional-grade chargers support up to 6s batteries and you should be good.
Some basic chargers like the one on the left might support a maximum of 4s and if you ever decide between advancing through the hobby and switching to 6s you will have to shell out extra cash. A disadvantage to these types of chargers is that they are inaccurate to some extent and they do not offer the users the option to tweak the input current and the option to discharge the battery.
Parallel Charging Boards
I probably mentioned parallel charging boards a dozen times already. What are parallel charging boards? Parallel charging boards are components that help to charge multiple batteries from a single charging port. Not all chargers have multiple charging ports and charging 10 batteries requires a lot of time (roughly an hour per battery) from a single port. Hence we have parallel charging boards.
The parallel charging board works by splitting the current coming from the charger to all the ports on the board. For example, if a parallel charging board has 5 ports and 5 batteries are connected, then the current coming from the charger is divided into all 5 ports.
But there’s a small catch to it. Only batteries of similar voltages and capacities can be charged together as the charger views all 5 batteries as 1 single larger battery. If batteries of different capacities are connected, then the battery with a smaller capacity might get overcharged and get damaged in the process.
POWER SUPPLY BASICS
Traditionally we are used to taking any charger, our phone charger for example, and hooking it up to the wall socket and expecting the phone to charge. That should be the same case with FPV chargers right? Well, kind of. Some chargers come with integrated power supplies, some don’t.
As mentioned earlier, Chargers like the ISDT Q6 pro or the Q6 plus do not come with a built-in power supply and need an external power supply to provide power to the charger. Now let’s talk in more technical terms. Every charger has something called a power rating. The ISDT Q6 is rated for a maximum power of 300W (spelled as 300 watts). Power is the product of voltage and current.
Power (P) = Voltage (V) x Current (I)
To exploit the full potential of the Q6, the power supply must be able to provide at least 300W of power. A power supply generally has a fixed voltage and a maximum rated current. For example, if a power supply has a fixed voltage of 12v and can provide a maximum current of 10A then the power rating of the power supply is 120W (12v x 10A). Suppose the maximum current was increased to 20A then the power rating is 240W (12v x 20A).
So we can just buy a 12v 30A power supply and be done with it right!! No. To higher charge voltage batteries, 5s or 6s then a 12v power supply would not be sufficient. But, a 24v power supply can provide 300W of power with a current rating of 12.5A.
Also, higher current-rating power supplies require beefier internal components and tend to be more expensive than lower current-rated batteries. Hence as a general rule of thumb, a 24v power supply with at least 10A of current rating would work well for most setups.
Our pick for a power supply
FIELD CHARGING BATTERIES
Field charging batteries might be one of the most practical and cost-effective approaches to flying longer in a single flying session. Of course, you can buy lots of batteries to fly without having to wait for batteries to charge but then again, a 4s battery costs $40 and buying 20 batteries easily pushes the investment on batteries to $800 alone, with a good spaced quad costing around $250.
With advancements in technology taking place every day and better batteries being developed, the technology available today might be outdated 1 year down the line. Hence a significant investment in an immature system is not recommended. Hence buying a small number of batteries often is a wiser choice.
There are many ways to charge a battery on the field. Some methods include buying a large 4s or 6s 20,000mAh or higher capacity battery. This is the most practical and viable approach. Field charging is a lot safer than charging the batteries in your home, as you don’t have to worry about the batteries exploding or catching fire.
The Energy Density of the larger battery plays a role in how much smaller batteries can be charged. A 6s 20,000mAh battery has an Energy Density of 504Wh (25.2 x 20) and a 4s 1500mAh battery has an Energy Density of 25.2Wh (16.8 x 1.5). So technically a 6s 20,000mAh battery can charge 20 (504 divided by 25.2) 4s 1500mAh battery.
Another method would be to use a mini generator to charge the batteries, but a generator costs a lot of money with a decent generator costing around $950 from Honda, and tend to get noisy. Some people use their car batteries to charge their LiPOs. But if the car battery is discharged enough, then you won’t be able to start your car and will need some towing.
Conclusion
FPV chargers are long-time investments that stick around for a while and investing in a good quality FPV charger would benefit the user in the long run and eventually save money. A bad FPV charger cannot charge your battery and will slowly damage batteries and kill your investments slowly. Lastly, if you plan to field charge batteries you will just have to charge one larger battery and go to the field rather than buying a generator and worrying about lugging that thing around.