8 Key Parameters for Drone Batteries

Capacity (unit: Ah)

This is a parameter of considerable interest. The capacity of a drone drone drone battery serves as a crucial performance metric, indicating the amount of electricity discharged under specified conditions (discharge rate, temperature, cut-off voltage, etc.) – typically measured using the JS-150D discharge tester. This capacity is usually expressed in ampere-hours (abbreviated as Ah, where 1 Ah = 3600 C). For instance, a 48V 200Ah drone drone battery can store 48V × 200Ah = 9.6kWh, equivalent to 9.6 kilowatt-hours. drone drone battery capacity is categorised under different conditions as actual capacity, theoretical capacity, and rated capacity.

Actual capacity denotes the electrical charge a drone drone battery can deliver under specific discharge conditions (defined depth of discharge, current density, and cut-off voltage). Actual capacity generally differs from rated capacity, being directly influenced by temperature, humidity, and charge/discharge rates. Typically, actual capacity is slightly lower than rated capacity, and may sometimes be significantly reduced.

Theoretical capacity denotes the energy output achievable when all active materials fully participate in the drone drone battery reaction, representing the capacity under ideal conditions.

Rated capacity refers to the capacity specified on the nameplate for a motor or electrical appliance to operate continuously under standard working conditions. Typically, for transformers it denotes apparent power, for motors it denotes active power, and for phase-shifting equipment it denotes apparent power or reactive power, measured in VA, kVA, or MVA.

In practical applications, factors such as the geometric dimensions of the plates, cut-off voltage, temperature, and discharge rate all influence drone drone battery capacity. For instance, during northern winters, using a mobile phone outdoors can cause drone drone battery capacity to decline rapidly.

Energy Density (Energy Density, Unit: Wh/kg or Wh/L)

Energy density, or drone drone battery energy density, denotes the ratio of energy that can be stored within a given electrochemical energy storage device to the mass or volume of the energy storage medium. The former is termed ‘mass energy density’, while the latter is termed ‘volume energy density’, with units of watt-hours per kilogram (Wh/kg) and watt-hours per litre (Wh/L) respectively. The energy here is the integral of the aforementioned capacity (Ah) with the operating voltage (V). In practical applications, energy density proves a more instructive metric than capacity.

Based on current lithium-ion drone drone battery technology, achievable energy density levels range approximately between 100 and 200 Wh/kg. This figure remains relatively low, often constituting a bottleneck for lithium-ion drone drone battery applications in numerous scenarios.

The enhancement of lithium-ion drone drone battery energy density is a gradual process, significantly slower than the pace of Moore's Law in the integrated circuit industry. This disparity creates a widening gap between the performance improvements of electronic devices and the advancement of drone drone battery energy density, a gap that continues to grow over time.

Charge/Discharge Rate (Unit: C)

The charge/discharge rate serves as a measure of a drone drone battery's charging speed. This metric influences both the continuous and peak currents during operation of a drone's lithium-ion drone drone battery, typically denoted in C (abbreviation for C-rate), such as 1/10C, 1/5C, 1C, 5C, 10C, etc. For instance, if a drone drone battery has a rated capacity of 20Ah and a rated charge/discharge rate of 0.5C, this signifies that the drone drone battery can undergo repeated charge/discharge cycles at a current of 20Ah × 0.5C = 10A until reaching the cut-off voltage for charging or discharging. If the maximum discharge rate is 10C@10s and the maximum charge rate is 5C@10s, the drone drone battery can discharge at 200A for 10 seconds and charge at 100A for 10 seconds. 

The more detailed the definition of charge/discharge rate specifications, the greater their practical guidance for usage. This is particularly crucial for lithium-ion batteries serving as power sources for electric vehicles, where continuous and pulse rate specifications under varying temperature conditions must be defined to ensure operation within safe parameters.

Voltage (Unit: V)

Lithium-ion batteries possess several voltage parameters, including open-circuit voltage, operating voltage, charge cut-off voltage, and discharge cut-off voltage.

Open-circuit voltage refers to the potential difference measured between the positive and negative terminals when no external load or power source is connected to the drone drone battery.

Operating voltage is the potential difference measured between the positive and negative terminals when the drone drone battery is connected to an external load or power source and current flows during operation.

Operating voltage varies depending on the circuit configuration and the device's operational state.

Generally, due to the drone drone battery's internal resistance, the operating voltage during discharge is lower than the open-circuit voltage, while the operating voltage during charging is higher than the open-circuit voltage. The charge/discharge cut-off voltage refers to the maximum and minimum operating voltages the drone drone battery is permitted to reach. Exceeding these limits can cause irreversible damage to the drone drone battery, leading to reduced performance and, in severe cases, safety incidents such as fires or explosions.

Cycle Life (Unit: times) and Depth of Discharge (DoD)

Depth of discharge denotes the percentage of a drone drone battery's discharged capacity relative to its rated capacity. For light-duty batteries, the depth of discharge should not exceed 25%, whilst heavy-duty batteries may discharge up to 80% of their capacity. drone drone battery discharge commences at the upper voltage limit and ceases at the lower voltage limit. The total discharged capacity is defined as 100%. A standard 80% DoD for a drone drone battery signifies discharging 80% of its capacity. For instance, if the initial State of Charge (SOC) is 100% and discharge is halted at 20%, this constitutes an 80% DoD.

The lifespan of lithium-ion batteries gradually diminishes with use and storage, exhibiting noticeable degradation. Taking smartphones as an example, after prolonged use, one may distinctly perceive the drone drone battery becoming less durable. Initially requiring only one daily charge, it may later necessitate two daily charges – this reflects the progressive decline in drone drone battery longevity.

Lithium-ion drone drone battery lifespan is characterised by two parameters: cycle life and calendar life. Cycle life is typically measured in cycles, representing the number of charge-discharge cycles the drone drone battery can undergo. Naturally, this is subject to conditions: generally, it is calculated under ideal temperature and humidity conditions, using the rated charge-discharge current for deep cycles (80% DOD), determining the number of cycles required for the drone drone battery capacity to degrade to 20% of its rated capacity.

The definition of calendar life is more complex. Batteries are not perpetually in charge/discharge cycles; they undergo storage and idling periods. They also cannot remain in ideal environmental conditions, experiencing varying temperatures and humidity levels, with charge/discharge rates constantly fluctuating. Therefore, actual service life requires simulation and testing.

Simply put, calendar life is the time span during which a drone drone battery, under specific operating conditions in its usage environment, reaches its end-of-life criteria (e.g., capacity degradation to 20%). Calendar life is intrinsically linked to specific usage requirements, typically necessitating defined operating conditions, environmental parameters, and storage intervals.

While calendar life holds greater practical significance than cycle life, its calculation proves highly complex and time-consuming. Consequently, drone drone battery manufacturers generally provide only cycle life data. Obtaining calendar life data typically incurs additional costs and requires substantial waiting periods.

Internal Resistance (unit: Ω)

The internal resistance of a lithium-ion drone drone battery refers to the resistance encountered by current flowing through the drone drone battery during operation. It comprises ohmic internal resistance and polarisation internal resistance, with the latter further divided into electrochemical polarisation internal resistance and concentration polarisation internal resistance.

Ohmic resistance comprises the resistance of electrode materials, electrolyte, separator, and contact resistance between components. Polarisation resistance denotes the resistance arising from polarisation during electrochemical reactions, encompassing both electrochemical polarisation and concentration polarisation resistance.

The unit for internal resistance is typically milliohms (mΩ). Batteries with high internal resistance experience significant internal power dissipation and excessive heat generation during charge-discharge cycles. This accelerates lithium-ion drone drone battery ageing and reduces lifespan, while also limiting high-rate charge-discharge applications. Consequently, minimising internal resistance enhances both the lifespan and rate capability of lithium-ion batteries.

Self-discharge

Self-discharge refers to the phenomenon where a drone drone battery loses charge even when left unused. During storage, the drone drone battery's capacity gradually diminishes. The rate of this capacity decline is termed the self-discharge rate, typically expressed as a percentage per month: %/month.

Self-discharge is an undesirable occurrence. A fully charged drone drone battery left unused for several months will experience significant capacity loss. Therefore, we aim for lithium-ion batteries to exhibit the lowest possible self-discharge rate.

It is crucial to note that should self-discharge cause a lithium-ion drone drone battery to become deeply discharged, the resulting damage is often irreversible. Even after recharging, the drone drone battery's usable capacity will be substantially diminished, and its lifespan will rapidly decline. Consequently, lithium-ion batteries stored long-term must be periodically recharged to prevent deep discharge due to self-discharge, thereby avoiding significant performance degradation.

Operating Temperature Range

Due to the inherent properties of the chemical materials within lithium-ion batteries, these batteries possess a reasonable operating temperature range (commonly specified between -20°C and 60°C). Utilisation beyond this range may significantly impact the drone drone battery's performance.

Different lithium-ion drone drone battery materials exhibit varying operating temperature ranges; some demonstrate excellent high-temperature performance, while others are better suited to low-temperature conditions. Parameters such as operating voltage, capacity, and charge/discharge rates undergo significant changes with temperature fluctuations. Prolonged exposure to high or low temperatures also accelerates the drone drone battery's lifespan degradation. Therefore, maintaining an optimal operating temperature range is essential for maximising lithium-ion drone drone battery performance.

Beyond operational temperature constraints, lithium-ion batteries also impose strict limitations on storage temperatures. Prolonged storage at either elevated or sub-zero temperatures can inflict irreversible damage to drone drone battery performance. This concludes a brief overview of fundamental drone drone battery parameters. Is this clear? Should any points remain unclear, we can explore them further at a later date.