Skip to content

Protective Circuits

Cell protections

Lithium ion cells have built-in safety devices, such as PTC (Positive thermal Coefficient, which creates a high resistance on high current surges) and CID (Current Interrupted Device, which opens the circuit when the pressure increases above 10 bars) for cylindrical cells. Pouch cells integrate a Protective Circuitry Board, which is a an electronic circuit than handles the UVLO (Under Voltage Lock out) and the OVP (Over Voltage Protection).

Block protections, BMS

At the module level, a BMS (Battery Managenemt System) is added, namely to ensure the communication with other components. This circuit securises the input and output current, the instantaneous voltage and checks the temperature. The BMS also handles the cell balancing, calculates the SOC and prevents the charge below 0°C.

Precautions for use

Lithium-ion batteries shall not :

  1. Be charged below 0°C : this permanently damages the anode.
  2. Be discharged below the discharge Cut-off voltage (approx. 2.5V) : this damages the cell.
  3. Be charged above the charge cut-off voltage (approx 4.2V), for security reasons.