- ⚠️ The battery packs produced by the MIUTA Electric Co. have no electronic built-in control circuitry (BMS – Battery Management System). For charging process requires a smart charger with overcharge protection and cell balancing functions (excluding the battery pack with self-balancing cell design). Also, the battery packs should be connected to the electric engines and to the electronic components of UAV/drone/missile only through a suitable power distribution board (PDB) or power electronic circuits.
- 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 cell lifespan).
- At cell-level, the standard charge condition is CC/CV. 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 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) – an internal engineered mechanism inside the cell can, a fuse-type that cuts off the electrical circuit permanently when triggered by excessive cell pressure, high temperature, or high voltage (overcharging) – may activate if the battery is charged without BMS (Battery Management System), continuously, after it has reached a fully-charged state or if the battery is charged at an extreme/high temperature. Please follow the instructions of MIUTA Electric Co. about the 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.
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 power supply 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 MIUTA Electric Co. will not be liable for any damages that are caused by violations of the precautions in this specification.
- The MIUTA Electric Co. 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 MIUTA Electric Co. 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 MIUTA Electric Co. 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 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 battery life (full cycle means 2.50V – 4.20V, but this will affect the chemistry and health of the battery cell).
For example, 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.
(*) – The voltage values expressed (V) are valid only for battery cells with the following chemistry: NCR, NMC, ICR, INR, LMO, LCO.
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