Page 664 of 878
6644-3. Do-it-yourself maintenance
12-volt battery ■ Location
The 12-volt battery is located on
the left-hand side of the luggage
compartment.
■ Removing the 12-volt battery cover
Vehicles with a compact spare tire
Pull the lever upward to fold
back the front part of the deck
board.
Pull the folded deck board
upright.STEP 1
STEP 2
Page 665 of 878
6654-3. Do-it-yourself maintenance
4
Maintenance and care Pull on the attached hook to
extend the string.
Use the hook to secure the deck
board as shown in the illustra-
tion.
Remove the spare tire cover.
After removing the clips,
remove the 12-volt battery
cover.STEP 3
STEP 4
STEP 5
STEP 6
Page 667 of 878
6674-3. Do-it-yourself maintenance
4
Maintenance and care After removing the clips,
remove the 12-volt battery
cover.
■ Exterior
Make sure that the 12-volt ba ttery terminals are not corroded and
that there are no loose connect ions, cracks or loose clamps.
Terminals
Hold-down clamp
■ Installing the 12-volt battery cover
Install the 12-volt battery cover
with the clips.STEP 4
Page 668 of 878

6684-3. Do-it-yourself maintenance
■
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
The hybrid system may not start. Follow one or both of the following procedures: ●
After opening and closing the driver’s do or, wait 10 seconds and then attempt to
start the hybrid system. (If the system does not start the first time, repeat the pro-
cedure.)●
With the shift lever in P and the “POWER” switch off, open and close any door
and then attempt to start the hybrid system.
If the system will not start even after mult iple attempts at both methods, contact
your Lexus dealer.
CAUTION■
Chemicals in the 12-volt battery
The 12-volt battery contain poisonous and corrosive sulfuric acid and may produce
hydrogen gas which is flammable and explosiv e. To reduce the risk of death or seri-
ous injury, take the following precautions while working on or near the 12-volt bat-
tery: ●
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.
Page 669 of 878

6694-3. Do-it-yourself maintenance
4
Maintenance and care CAUTION■
Where to safely charge the 12-volt battery
Always charge the 12-volt battery in an open area. Do not charge the 12-volt bat-
tery in a garage or closed room where there is insufficient ventilation.■
How to recharge the 12-volt battery
Only perform a slow charge (5 A or le ss). The 12-volt battery may explode if
charged at a quicker rate.■
Emergency measures regarding electrolyte ●
If electrolyte gets in your eyes
Flush your eyes with clean water for at least 15 minutes and get immediate medi-
cal 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 atten-
tion 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 imme-
diately.■
When replacing the 12-volt battery
Use a 12-volt battery designed for the RX 450h. 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 your Lexus dealer.
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.
Page 687 of 878
6874-3. Do-it-yourself maintenance
4
Maintenance and care Electronic key battery Replace the battery with a new one if it is discharged.
■ You will need the following items:
● Flathead screwdriver
● Small Phillips-head sc rewdriver
● Lithium battery (CR1632)
■ Replacing the battery
Take out the mechanical key.
Remove the cover.
Remove the depleted battery.
Insert a new battery with the “+”
terminal facing up.STEP 1
STEP 2
STEP 3
Page 688 of 878

6884-3. Do-it-yourself maintenance
■
Use a CR1632 lithium battery ●
Batteries can be purchased at your Le xus dealer, local electrical appliance
shops or camera stores.●
Replace only with the same or equivalent type recommended by the manufac-
turer.●
Dispose of used batteries according to the local laws.■
If the electronic key battery is discharged
The following symptoms may occur: ●
The smart access system with push-button start and wireless remote control will
not function properly.●
The operational range is reduced.■
When the card key battery needs to be replaced (if equipped)
The battery for the card key is available only at Lexus dealers. Your Lexus dealer
can replace the battery for you.
CAUTION■
Removed battery and other parts
These parts are small and if swallowed by a child, they can cause choking. Keep
away from children. Failure to do so could result in death or serious injury.
NOTICE■
For normal operation after replacing the battery
Observe the following precautions to prevent accidents:
●
Always work with dry hands.
Moisture may cause the battery to rust.
●
Do not touch or move any other comp onents inside the remote control.
●
Do not bend either of the battery terminals.
Page 689 of 878
6894-3. Do-it-yourself maintenance
4
Maintenance and care Checking and replacing fuses If any of the electrical components do not operate, a fuse may have blown.
If this happens, check and re place the fuses as necessary.
Turn the “POWER” switch off.
After a system failure, see “Fuse layout and amperage ratings”
for details about which fuse to check. ( P. 694)
Engine compartment:
To gain access to the fuse box, remove the engine compart-
ment cover. ( P. 655)
Luggage compartment:
To gain access to the fuse box, secure the deck board with
the hook and then remove th e spare tire cover and 12-volt
battery cover. ( P. 664)
Open the fuse box cover.
Engine compartment (type A fuse box)
Push the tab in and lift the lid off.
Engine compartment (type B fuse box)
Push the tab in and lift the lid off.STEP 1
STEP 2
STEP 3
STEP 4