Toyota Camry Hybrid AHV40 Manual page 28

TH-28
4. HV Battery
General
D The '07 Camry Hybrid model uses sealed nickel metal hydride (Ni-MH) HV batteries. The HV batteries
have a high power density, are lightweight and offer longevity to match the characteristics of the THS
II. Because the THS II effects charge/discharge control to maintain the HV batteries at a constant SOC
(state of charge) level while the vehicle is operating normally, it does not need to be recharged externally.
D The HV batteries use nickel-plated, metal container type cells to realize enhanced cooling performance
and a compact construction. As a result, high power density, lightweight construction, and longevity have
been accomplished at high levels.
D The HV battery unit consists of 34 separate batteries. The batteries each comprise 6 cells and they are
connected to each other in series through a bus bar module. The cells of the batteries are connected at
two locations in order to reduce the internal resistance and improve efficiency. The HV battery unit,
which has a total of 204 cells (6 cells x 34 batteries) and a nominal voltage of 244.8 V (1.2 V x 204 cells),
is located in the luggage compartment behind the rear seat.
D A junction block, battery smart unit and DC/DC converter are used. Integrated into the junction block
are an SMRG (System Main Relay Ground), SMRB (System Main Relay Battery) and a current sensor.
The battery smart unit monitors the HV battery. The DC/DC converter supplies power to the auxiliary
battery after decreasing the nominal voltage of DC 244.8 V supplied by the HV battery to DC 12 V. Power
to the lights, audio system, air conditioning system (except the electric inverter compressor) and ECUs
is supplied by the auxiliary battery.
The battery smart unit, junction block, and DC/DC converter are located in the battery front side carrier,
which is in the same housing as the HV battery unit. This realizes a compact package.
D An air-cooling method, which uses a dedicated cooling fan to cool the HV battery with air from inside
the cabin, is employed. A dedicated cooling fan is also provided for the DC/DC converter. Thus, highly
efficient air-cooling has been achieved.
D A service plug that shuts off the circuit is provided in the middle of the HV battery modules (between
No.18 and No.19 batteries). Before servicing any portion of the high-voltage circuit, be sure to remove
the service plug.
Exhaust Duct
THS II (TOYOTA HYBRID SYSTEM II)
Intake Duct
Rear Seat
Cooling Fan
HV Battery
Unit
02HTH27TE