HV Battery
What is a HV Battery?
"high-voltage" battery, pack of battery cells arranged in such a way to produce a large output voltage
What is the voltage output range of the current sensor?
0.5 - 2,5V for charge, 2.5-4.5 for discharge <0.5V indicates error 5V reserved for failure
What are the pins of the current sensor?
73: voltage supply; 74: Hall signal; 75: ground
Where could the HV battery be found?
Either the boot or base of the vehicle.
What kind of batteries does an EV have?
HV battery + 12V battery
Describe the current sensor.
Hall effect sensor (measures DC); measures inpuLt and output currents of the HV battery; used to calculate the SOC of the HV battery
What is the function of the HV battery?
Provide high voltage components with electricity
What is the function of the 12V battery?
Provide onboard auxiliary components with electricity
What is the function of the battery control unit?
Regulate processes for the HV battery.
Describe the battery cooling system.
air is drawn from passenger space and blown between modules, then the warm air is channeled outside
What composes a HV battery system?
battery modules, service plug, main relays, current sensor, battery ECU, cooling system
Battery ECU measures...
battery temp cooling air temp i/o battery currents voltage per module
What is inrush current?
capacitor in the inverters causes a short high-charging current when switched on; the series resistor limits that current
Current enters battery during...
charging and regenerative braking
What is the main function of battery ECU?
gathers info to optimize battery condition keeps cells in balance controls fan calculates SOC limits or prevents overcharge/discharge in case of failure
What are the characteristics of a Lithium-Ion (LI-ion) battery?
high source voltage, large # charging cycles, large energy density, expensive
Describe the service plug.
isolate high voltage from HV system during emergencies or repairs; usually orange; contains a fuse to prevent current overload and protect battery
What are the characteristics of a Nickel Metal-Hydride (NiMh) battery?
low source voltage, cheap, medium energy density, high energy per volume
Battery cells are connected in...
parallel, to maximize capacity.
Battery modules are connected in...
series, to maximize voltage.
Describe a battery module.
store energy; cells in parallel to maximize capacity, modules in series to maximize output voltage
Describe the three main relays.
two relays electrically isolate HV battery from remainder of the vehicle, one connects a resistor in series to limit the inrush current when the capacitors are charged
Current drains out of battery when...
vehicle is driven electrically
conditions req'd for turning off the main relay in hybrid or electric vehicles
wtf