Maintaining your drone battery is one of the key steps in ensuring the continued high performance of your FPV drone. Whether you are a professional flyer or just starting out, properly maintaining and managing your battery can extend its life and provide longer flight times. In the following points, I will provide you with some short beginnings to help you effectively care for your FPV drone batteries.

Introduction of FPV battery parameters

The battery Compared with the general rechargeable batteries, lithium polymer batteries have a higher charge and discharge efficiency, but the safety is poor, overcharge or over discharge may lead to permanent loss of battery, or even burn and explode. The battery of a traverser generally has the following parameters:

Number of cells (S)

The battery of a crossover machine usually consists of several power supply units (cells) connected in series, the voltage of a single cell is about 3.7V, and the number of cells is measured in S.

For example, a 4S lithium battery consists of 4 power supply units connected in series, with a total voltage of about 3.7V * 4 = 14.8V. In addition to ordinary lithium batteries, there are also high-voltage batteries with individual cells capable of reaching 4.35V or more, which can provide higher bursts of power during racing starts.

It is easy to see that the more the number of cells, the higher the voltage of the battery, the higher the maximum power that can be achieved. The 5-inch machine for entry-level use is generally recommended to match the 4S battery. Flyers who are looking for speed can choose 6S batteries.

Battery capacity (mAh)

Battery capacity = voltage x current x time, which can be simply understood as the longer the endurance time under certain voltage and current conditions, the greater the capacity.

The mA in the capacity unit represents mA, the unit of current, h represents hour, the unit of time, and the voltage is not marked and needs to be confirmed by the number of cells. Therefore, mAh does not directly represent the battery capacity.

For the same voltage battery, the higher the mAh, the higher the capacity. Similarly, for the same mAh battery, the higher the voltage, the higher the capacity.

Discharging capacity (C)

Discharge capacity can determine the maximum power output of a lithium battery. The maximum discharge current (I) of a battery = C x ampere-hour (Ah). Take a 10C 1200mAh (equivalent to 1Ah) lithium battery as an example, its maximum current is 10 x 1.2= 12A. Therefore, the higher the C value, the higher the power of the battery. The lithium battery of the crossover machine is generally between 80C ~ 120C.

Battery charging and discharging

The lithium battery of the crossover will usually have two interfaces, the power supply port and the balance charge interface.

Power supply port

The power supply port is the positive and negative interface of each core in series, consisting of two pins, which can be directly connected to the ESC to power the traverser. In order to support high current discharge, most common drones on the market use XT60 or the smaller XT30 power supply port, which is convenient to connect thicker wires.

As mentioned above, the maximum current of discharge can be calculated by the over C value. Exceeding the maximum current may cause the battery to bulge or even explode.
Over-discharging the lithium battery will cause irreversible loss of the battery, and the voltage of a single cell is recommended to be no less than 3.5V.

Balanced charging port

The other connector with the row of plugs is the balanced charging connector for charging. Each pin on the row of plugs is connected to the positive and negative terminals of each battery cell. When charging through the balance head, the charger can charge each cell with equal voltage, ensuring safety and increasing the utilization of each cell.

The maximum current for charging is usually calculated with 1C as the standard, for example, a 1000mAh (equivalent to 1Ah) Li-ion battery is charged at 1A.
After setting the type of battery (Lipo) and the maximum current inside the smart balance charger, you can plug in the balance head and start charging. The balance charger will automatically stop charging when the battery is full.
Overcharging the Li-ion battery will make the battery bulge or even explode, and the voltage of a single cell should not exceed 4.2V.

Note: The lithium battery of the traversing machine has no protection circuit, and must be guarded throughout the charging

Use of chargers

There are various charging solutions for Li-ion batteries, including infield charging solutions that can be directly connected to 220V AC power, and outfield charging solutions through vehicle power or high-capacity Li-ion batteries. In addition, because there are differences in power, some charging solutions can only charge one lithium battery, while others can charge multiple. Charging solutions need to be decided according to the scenario and budget.

Infield charging solution

Low current and low power

Able to meet basic charging needs, suitable for flyers with low flight frequency and limited budget.
Common small chargers can be plugged directly into the 220V power supply, through the light to indicate the charging status.

High Current High Power

High-current charging devices can charge multiple batteries at the same time for long flights.
Since lithium batteries use DC power for charging, high power chargers usually require an additional switching power supply that can convert 220V AC power to low voltage DC power.

High-current chargers are capable of charging multiple lithium batteries at the same time. The settings and operation of each charger differ, so you need to read the manual carefully before use to confirm how to set the maximum voltage and current for charging. Generally set the voltage to no more than 4.2V, and the current needs to be calculated according to the maximum charging current above. The quality of the charger is directly related to the safety factor, which also affects the life of the lithium battery and needs to be purchased carefully.

Some useful features of the advanced charger include:

• Supports intelligent charge/discharge mode for easy long-term battery storage.
• Low voltage state slowly charges activated batteries.
• Charges multiple batteries in sequence, cycle monitoring to maintain cell voltage.

Off-site charging solution

Off-site charging can choose 12V high-capacity handheld outdoor battery, or vehicle 12V power supply instead of switching power supply. This type of power supply has limited output power and needs attention when matching the charger.

Note: Outdoor batteries and car batteries over discharge will also directly affect the service life and require special attention.

Power and voltage

The power and voltage of Li-ion batteries are only proportional within a certain range, and can vary from cell to cell. Even consumer grade electronic products such as cell phones are difficult to calculate the remaining power accurately. The relationship between voltage and power of Li-ion battery can be roughly referred to the following table.

Battery storage

Lithium batteries that are not used for a long time need to ensure that the voltage of the cells is between 3.5V and 3.9V. The battery will also have a weak self-discharge when not in use, so it needs to complete a charge/discharge cycle every 2~3 months, too high or too low voltage will easily lead to bulging.

Battery abnormal treatment

Short circuit
The battery will be seriously heated when short-circuited, causing the components to smoke. Do not touch the metal wires directly when they are hot. The shorted wire can be immediately removed with scissors.

Bulge

Do not poke the bulging battery, it may lead to leakage or even spontaneous combustion.
Although the battery with a slight bulge does not have a significant impact on performance, there are safety hazards such as liquid and gas leakage, so it is recommended to dispose of the battery in accordance with laws and regulations.

Liquid leakage

The battery is prone to rupture and leakage when blowing up, so pick it up carefully and dispose of it in accordance with laws and regulations. Do not directly contact the liquid with the skin.