2012 Lexus HS250h battery

5
When trouble arises
549
5-2. Steps to take in an emergency
HS250h_U_75050U
■Starting the hybrid system when the 12-volt battery is discharged
The hybrid system cannot be started by push-starting.
■To prevent 12-volt battery discharge
●Turn off the headlights and the audio system while the hybrid system is off.
●Turn off any unnecessary electrical components when the vehicle is running at a
low speed for an extended period, such as in heavy traffic.
■When the 12-volt battery is discharged
●The hybrid system may not start. (→P. 4 4 8 )
●If the 12-volt battery is depleted with the shift position in P, it will not be possible
to shift out of P. In this case, the vehicle cannot be towed without lifting both
front wheels because the front wheels are locked by the parking lock.
(→ P. 4 9 5 )
●When the 12-volt battery is reconnected, start the hybrid system, depress the
brake pedal, and confirm that it is possible to shift into each shift position.
■Charging the 12-volt battery
The electricity stored in the 12-volt battery will discharge gradually even when the
vehicle is not in use, due to natural discharge and the draining effects of certain
electrical appliances. If the vehicle is left for a long time, the 12-volt battery may dis-
charge, and the hybrid system may be unable to start. (The 12-volt battery
recharges automatically while the hybrid system is operating.)
Make sure the “READY” indicator comes on. If the indicator
does not come on, contact your Lexus dealer.
Once the hybrid system has started, remove the jumper cables
in the exact reverse order from which they were connected.
Close the exclusive jump starting terminal cover and reinstall
the fuse box cover.
Once the hybrid system starts, ha ve the vehicle inspected at your
Lexus dealer as soon as possible.

550
5-2. Steps to take in an emergency
HS250h_U_75050U
CAUTION
■Avoiding battery fires or explosions
The flammable gas that may be generated by the assisting vehicle battery may
catch fire and explode. Make sure to observe the following to prevent fire or sparks.
●Make sure each jumper cable is connected to the correct terminal and that it is
not unintentionally in contact with any part other than the intended terminal.
●Do not allow the other end of the jumper cable connected to the “+” terminal to
come into contact with any other parts or metal surfaces in the area, such as
brackets or unpainted metal.
●Do not allow the + and - clamps of the jumper cables to come into contact with
each other.
●Do not allow open flame or use matches, cigarette lighters or smoke near the
battery.
■12-volt battery precautions
The 12-volt battery contains poisonous and corrosive acidic electrolyte, while
related parts contain lead and lead compounds. Observe the following precautions
when handling the 12-volt battery:
●When working with the 12-volt battery, always wear safety glasses and take care
not to allow any battery fluids (acid) to come into contact with skin, clothing or the
vehicle body.
●Do not lean over the 12-volt battery.
●In the event that battery fluid comes into contact with the skin or eyes, immedi-
ately wash the affected area with water and seek medical attention. Place a wet
sponge or cloth over the affected area until medical attention can be received.
●Always wash your hands after handling the battery support, terminals, and other
battery-related parts.
●Do not allow children near the 12-volt battery.
■After recharging the 12-volt battery
Have the 12-volt battery inspected at your Lexus dealer as soon as possible.
If the 12-volt battery is deteriorating, continued use may cause the 12-volt battery to
emit a malodorous gas, which may be detrimental to the health of passengers.
■When replacing the 12-volt battery
→P. 4 5 0

5
When trouble arises
551
5-2. Steps to take in an emergency
HS250h_U_75050U
NOTICE
■Exclusive jump starting terminal precaution
The exclusive jump starting terminal is to be used when charging the 12-volt battery
from another vehicle in an emergency. It cannot be used to jump start another vehi-
cle.
■When handling jumper cables
When connecting the jumper cables, ensure that they do not become entangled in
the cooling fans or belt.

562
6-1. Specifications
HS250h_U_75050U
Fuel
Electric motor (Traction motor)
Hybrid battery (Traction battery)
Fuel typeUnleaded gasoline only
Octane rating87 (Research octane number 91) or higher
Fuel tank capacity
(Reference)14.5 gal. (55 L, 12.5 Imp. gal.)
Ty p ePermanent magnet synchronous motor
Maximum output105 kW
Maximum torque199 ft•lbf (270 N•m, 27.5 kgf•m)
Ty p eNickel-metal hydride battery
Vo l t a g e7. 2 V/m o d u l e
Capacity6.5 Ah (3HR)
Quantity34 modules
Overall voltage244.8 V

565
6-1. Specifications
6
Vehicle specifications
HS250h_U_75050U
Ignition system
Electrical system
Hybrid transaxle
*: The fluid capacity is a reference quantity. If replacement is necessary, contactyour Lexus dealer.
Spark plug
Make
GapDENSO SK20R11
NGK IFR6A11
0.043 in. (1.1 mm)
NOTICE
■Iridium-tipped spark plugs
Use only iridium-tipped spark plugs. Do not adjust spark plug gap.
12-volt battery
Open voltage* at
68 °F (20 °C):12.6  12.8 V Fully charged
12.2 
12.4 V Half charged
11.8 
12.0 V Discharged
(*: Voltage checked 20 minutes after the hybrid sys-
tem and all the lights are turned off)
Charging rates5 A max.
Fluid capacity *4.4 qt. (4.2 L, 3.7 Imp. qt.)
Fluid typeTo y o t a G e n u i n e AT F W S

579
6-1. Specifications
6
Vehicle specifications
HS250h_U_75050U
Occupant distributionDistribution of occupants in a vehicle as specified in
the third column of Table 1
* below
Production options
weight
The combined weight of installed regular production
options weighing over 5 lb. (2.3 kg) in excess of the
standard items which they replace, not previously
considered in curb weight or accessory weight,
including heavy duty brakes, ride levelers, roof rack,
heavy duty battery, and special trim
RimA metal support for a tire or a tire and tube assembly
upon which the tire beads are seated
Rim diameter
(Wheel diameter)Nominal diameter of the bead seat
Rim size designationRim diameter and width
Rim type designationThe industry manufacturer’s designation for a rim by
style or code
Rim widthNominal distance between rim flanges
Vehicle capacity weight
(Total load capacity)The rated cargo and luggage load plus 150 lb. (68
kg) times the vehicle’s designated seating capacity
Vehicle maximum load on
the tireThe load on an individual tire that is determined by
distributing to each axle its share of the maximum
loaded vehicle weight, and dividing by two
Vehicle normal load on
the tire
The load on an individual tire that is determined by
distributing to each axle its share of curb weight,
accessory weight, and normal occupant weight (dis-
tributed in accordance with Table 1
* below), and
dividing by two
We a t h e r s i d eThe surface area of the rim not covered by the
inflated tire
Ti r e r e l a t e d t e r mMeaning

595
6-2. Customization
6
Vehicle specifications
HS250h_U_75050U
CAUTION
■Cautions during customization
As the hybrid system needs to be running during customization, ensure that the
vehicle is parked in a place with adequate ventilation. In a closed area such as a
garage, exhaust gases including harmful carbon monoxide (CO) may collect and
enter the vehicle. This may lead to death or a serious health hazard.
NOTICE
■During customization
To prevent 12-volt battery discharge, ensure that the hybrid system is running while
customizing features.

596
HS250h_U_75050U
6-3. Initialization
Items to initialize
ItemWhen to initializeReference
Maintenance dataAfter the maintenance is performedP. 4 2 4
Tire pressure warning
system
• When rotating the tires on vehicles with differing front and rear tire infla-
tion pressures
•When changing the tire size
P. 4 5 2
The following items must be initialized for normal system operation after
such cases as the 12-volt battery being reconnected, or maintenance
being performed on the vehicle.