Page 499 of 688
4957-3. Do-it-yourself maintenance
CT200h_OM_OM76102E_(EE)
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Maintenance and care
Engine compartment
12-volt battery
P. 504
Engine coolant reservoir (P.
501)
Engine oil level dipstick (P.
497)
Engine oil filler cap (P. 497)
Power control unit coolant
reservoir (P. 501)Fuse box (P. 534)
Radiator (P. 502)
Condenser (P. 502)
Electric cooling fans
Washer fluid tank (P. 503)1
2
3
4
5
6
7
8
9
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5047-3. Do-it-yourself maintenance
CT200h_OM_OM76102E_(EE)
12-volt battery
The 12-volt battery is located in the
right-hand side of luggage compart-
ment.
Open the center and right side deck boards. (P. 470)
Remove the center auxiliary box. (P. 593)
Remove the right side auxiliary
box.
Remove the 12-volt battery
maintenance cover.
Location
Removing the 12-volt battery maintenance cover
1
2
3
4
Page 509 of 688
5057-3. Do-it-yourself maintenance
CT200h_OM_OM76102E_(EE)
7
Maintenance and care
Make sure that the 12-volt battery terminals are not corroded and that
there are no loose connections, cracks, or loose clamps.
Te r m i n a l s
Hold-down clamp
The meanings of each caution symbol on the top of the 12-volt battery are
as follows:
Exterior
1
2
Caution symbols
No smoking, no naked
flames, no sparksBattery acid
Shield eyesNote operating
instructions
Keep away from chil-
drenExplosive gas
Page 510 of 688
5067-3. Do-it-yourself maintenance
CT200h_OM_OM76102E_(EE)
Insert the 2 tabs on the far side of
the cover into the holes.
Hook on the 2 tabs on the near
side of the cover.
Hook on the 2 tabs on the upper
side of the cover.
Installing the 12-volt battery maintenance cover
1
2
3
Page 511 of 688

5077-3. Do-it-yourself maintenance
CT200h_OM_OM76102E_(EE)
7
Maintenance and care
Before recharging
When recharging, the 12-volt battery produces hydrogen gas which is flammable
and explosive. Therefore, observe the following precautions before recharging:
If recharging with the 12-volt battery installed on the vehicle, be sure to discon-
nect the ground cable.
Make sure the power switch on the charger is off when connecting and discon-
necting the charger cables to the 12-volt battery.
After recharging/reconnecting the 12-volt battery
Unlocking the doors using the smart entry & start system may not be possible
immediately after reconnecting the 12-volt battery. If this happens, use the
wireless remote control or the mechanical key to lock/unlock the doors.
Start the hybrid system with the power switch in ACCESSORY mode. The
hybrid system may not start with the power switch turned off. However, the
hybrid system will operate normally from the second attempt.
The power switch mode is recorded by the vehicle. If the 12-volt battery is
reconnected, the vehicle will return the power switch mode to the status it was
in before the 12-volt battery was disconnected. Make sure to turn off the power
before disconnect the 12-volt battery. Take extra care when connecting the 12-
volt battery if the power switch mode prior to discharge is unknown.
Restart the hybrid system, depress the brake pedal, and confirm that it is possi-
ble to shift into each shift position.
If the system will not start even after multiple attempts at all methods above,
contact any authorized Lexus dealer or repairer, or another duly qualified and
equipped professional.
Page 512 of 688

5087-3. Do-it-yourself maintenance
CT200h_OM_OM76102E_(EE)
WA R N I N G
Chemicals in the 12-volt battery
The 12-volt battery contains poisonous and corrosive sulfuric acid and may
produce hydrogen gas which is flammable and explosive. To reduce the risk of
death or serious injury, take the following precautions while working on or near
the 12-volt battery:
Do not cause sparks by touching the 12-volt battery terminals with tools.
Do not smoke or light a match near the 12-volt battery.
Avoid contact with eyes, skin and clothes.
Never inhale or swallow electrolyte.
Wear protective safety glasses when working near the 12-volt battery.
Keep children away from the 12-volt battery.
Where to safely charge the 12-volt battery
Always charge the 12-volt battery in an open area. Do not charge the 12-volt
battery in a garage or closed room where there is insufficient ventilation.
How to recharge the 12-volt battery
Only perform a slow charge
*. The 12-volt battery may explode if charged at a
quicker rate.
*: 4.2 A or less on vehicles with a S46B24R battery
3.5 A or less on vehicles with a S34B20R battery
Emergency measures regarding electrolyte
If electrolyte gets in your eyes
Flush your eyes with clean water for at least 15 minutes and get immediate
medical attention. If possible, continue to apply water with a sponge or cloth
while traveling to the nearest medical facility.
If electrolyte gets on your skin
Wash the affected area thoroughly. If you feel pain or burning, get medical
attention immediately.
If electrolyte gets on your clothes
It can soak through clothing on to your skin. Immediately take off the clothing
and follow the procedure above if necessary.
If you accidentally swallow electrolyte
Drink a large quantity of water or milk. Get emergency medical attention
immediately.
When replacing the 12-volt battery
Use a 12-volt battery designed for this vehicle. Failure to do so may cause gas
(hydrogen) to enter the passenger compartment, causing a fire or explosion.
For replacement of the 12-volt battery, contact any authorized Lexus dealer or
repairer, or another duly qualified and equipped professional.
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5097-3. Do-it-yourself maintenance
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Maintenance and care
WA R N I N G
When disconnecting the 12-volt battery
NOTICE
When recharging the 12-volt battery
Never recharge the 12-volt battery while the hybrid system is operating. Also,
be sure all accessories are turned off.
Do not disconnect the negative (-) terminal
on the body side as shown. The discon-
nected negative (-) terminal may touch the
positive (+) terminal, which may cause a
short and result in death or serious injury.
Page 534 of 688
5307-3. Do-it-yourself maintenance
CT200h_OM_OM76102E_(EE)
Electronic key battery
Flathead screwdriver
Small Phillips-head screwdriver
Lithium battery CR1632
Ty p e A
Take out the mechanical key.
Remove the cover.
Replace the battery with a new one if it is depleted.
You will need the following items:
Replacing the battery
1
2