- The battery packs produced by the CMIUTA Electric Company have no any (BMS) electronic built-in circuitry. For charging process requires a smart charger with overcharge protection and cell balancing functions.
- The battery packs should be connected to the electric engines and to the electronic components of UAVs through a suitable power distribution board (PDB).
- The battery pack should be kept away from the heat generating electronic parts in order to avoid deterioration of cell performance.
- For safety reason and in order not to shorten the cycle life, max charging voltage should be under 4.20V/cell including tolerance (we recommend 4.10V/cell, to achieve more cycles – read below in page more info about NCA cell lifespan).
- At cell-level, the standard charge condition is CC/CV with the following rates:
– NCR18650GA = 1670mA/cell
– NCR20700B = 2000mA/cell
– NCR20700C 2200mA/cell
The charging process should be automatically halted by charging the device when either time, battery voltage, or current reach certain values. Read battery pack specs to see the maximum charging current. It differs from one configuration to another, depending on the number of cells in parallel!
- The discharge end voltage should be more than 2.70V/cell, including tolerance (we recommend high than 3.10V/cell, to achieve more cycles – read below in page more info about NCA cell lifespan)
- The charging temperature should be confined to the range 5°C to +45°C.
- The discharge temperature should be between -20°C to ＋60°C.
- Safety. Current Interrupt Device (CID) may activate if the battery is charged continuously after it has reached a fully-charged state or if the battery is charged at a high temperature. Please follow the instructions of CMIUTA Electric Company about charging method.
- Do not overtake continuous discharge rate, or peak current rate noted on the battery pack tech specification*. That will overheat the cells. The upper temp limit with permanently damaging the lithium-ion cell chemistry starts above 70°C. Subjecting the battery to a higher temperature may damage the polyolefin separator and can cause an internal short circuit. This may cause the battery to generate heat, smoke, catch fire, or explode.
⚠ WARNING (*):
It’s your responsibility for making sure your charger or equipment work properly. Only use the battery packs with proper protection circuitry – BMS or other power electronics are not included. The user must have an appropriate understanding of lithium-ion batteries before purchase. Use caution when working with and using lithium-ion batteries as they are very sensitive to charging characteristics and may explode, burn, or cause a fire if misused or mishandled. Never leave batteries charging unattended. Charge only with a smart charger designed for this specific type of lithium-ion battery. Buyer is responsible for any damage or injury caused by misuse or mishandling lithium-ion batteries and chargers. Misusing or mishandling lithium-ion batteries can lead to serious risk for personal injury, property damage, or death.
- DO NOT short circuit.
- DO NOT force a reverse-charge or a reverse-connection.
- DO NOT overcharge.
- DO NOT modify, disassemble, puncture, cut, crush, or incinerate.
- DO NOT expose to liquids.
- DO NOT use or place the battery at high temperatures.
- DO NOT connect the battery directly to AC plug (outlet) or electric car plugs.
In case of violation of the rules of use (*):
- The CMIUTA Electric Company will not be liable for any damages that are caused by violations of the precautions in this specification.
- The CMIUTA Electric Company will not be liable for any problems caused by design defects of the battery pack charger or other power electronics of your vehicle or aircraft. Also if you use improper settings of the smart charger or other electronic power boards, do it at your own risk.
Storage temperature and humidity.
- When long duration storage the battery packs should be stored in a stable environment characterized by low-humidity (less than 70%RH), free of corrosive gasses, and an ambient temperature between -20℃ and +20℃.
- Avoid conditions that can create condensation such as rapid fluctuations in the ambient.
Please see local regulations for recycling and disposal of lithium-ion batteries, or look for free recycling offers through funding events or retail stores.
Other battery safety requirements.
These batteries packs it is stringent engineered compliance with unmanned aircraft system requirements. In order to ensure the safety of the battery pack, please contact CMIUTA Electric Company to discuss the design of the application from a mechanical and electrical perspective. Also, if there are special usage conditions (for example a large (DC) current load, a quick charge method, or a special usage pattern), please consult CMIUTA Electric Company before finalizing the product specification.
What shortens lithium battery life.
- High temperatures.
- Overcharging or high voltage (battery SoC).
- Deep discharges or low voltage (battery DoD).
- High discharges or charge current.
How can you prolong the lithium-ion NCA battery lifespan?
- A partial discharge reduces stress and prolongs battery life, so does a partial charge.
- Batteries charging to 85% have a longer lifespan than enabling full charge. Although longer lasting, a less than a full cycle does not fully utilize a battery.
- 100% DoD is a full cycle; 10% are very brief. Cycling in mid-state-of-charge would have better longevity.
- Every 0.10V drop below 4.20V/cell doubles the cycle but holds less capacity.
- Every 75mV drop in charge voltage lowers the usable capacity by about 10%.
Referring to cycle, using a “working range” between 3.10V – 4.10V/cell (including tolerance) is one of the right setups to prolong the NCA battery pack life (full cycle means 2.50V – 4.20V, but this will affect the chemistry and health of the battery cell).
NCR18650GA has a lifespan up to 1000 cycles, and NCR20700B up to 2000 cycles, but these numbers strongly depend on discharge rate, SoC and DoD values, or cell temperature.
DoD = Depth of Discharge
SoC = State of Charge
BMS = Battery Management System
ESC = Electronic Speed Controller
PDB = Power Distribution Board
PCB = Printed Circuit Board
EV = Electric Vehicle
AC = Alternating Current
DC = Direct Current
UAVs = Unmanned Aerial Vehicles
UAS = Unmanned Aerial System