General Information

HEV Battery System
P1B70 High Voltage Battery Voltage Too Low - General Information

Component Location





General Description

** What is the High Voltage Battery System ?
The High Voltage Battery System consists of the Battery Management System Control Unit (BMS-ECU), Power Relay Assembly (PRA) and a Cooling Blower.
Each function is listed below :
- High Voltage Battery: Supplies electrical energy for acceleration and receives/stores electrical energy during deceleration.
- BMS ECU: Controls the High Voltage Battery by monitoring the voltage, current and temperature.
- PRA(Power relay assembly)consists of relays which link and cut high voltage, and finally, current sensor which monitors battery current. Those are an assembly in PRA.
- A safety plug : It can cut high voltage flowing as mechanically in order to protect technicians. And, there is a safety fuse in the safety plug that protect over current.
- Cooling Blower: Maintains proper High Voltage Battery temperature.
** The battery cell function and roles :
The High Voltage battery cell is the smallest unit of the High Voltage Battery pack.
The voltage of each cell is 3.75V. The battery pack will attain 270V by connecting all 72 cells in a series.
The BMS ECU monitors all of the 72 high-voltage cells, 5 battery temperature sensors, an ambient temperature sensor, a current sensor which checks the main battery and an auxiliary battery temperature sensor.
** The High-voltage battery specification is shown below :
Operating Voltage : for a battery pack : 200 - 310V (for a battery cell: 2.75 - 4.3)
Operating temperature : -30°C(-22°F)~55°C(131°F)
Storage temperature : -40°C(-40°F)~65°C(149°F)
Operating Current : During charge (-)200A~ During discharge (+)200A.
Field action when High Voltage Battery discharges






DTC Description

The BMS sets P1B70 when hybrid battery cell voltage is below 1.5V. If the DTC is current the Malfunction Indicator Lamp (MIL) will illuminate. If the hybrid battery cell voltage returns to normal the MIL will go out and the code will be stored in History.

DTC Detecting Condition





Specification





Diagnostic Circuit Diagram






















Signal Waveform & Data












Fig.1) The reference value at high-voltage battery 46% status - max. cell voltage 3.8V, Min. cell voltage is 3.76V and MCU Cap. Voltage is 274V at the EV mode status
Fig.2) State of Charge of Battery (48%) - Max cell voltage 3.8V Min cell voltage 3.76V and MCU Cap Voltage 274V at EV mode
Fig.3) State of Charge of Battery at 45.5% - Max 3.78V, Min 3.74V and MCU CAP 271V at EV mode with accelleration.