L-SB-0107-17

January 30, 2017

Maintenance for HV & Auxiliary Batteries
Service
Category

General

Section

Maintenance

Market USA

Applicability
YEAR(S)

MODEL(S)

2018

ES300H, GS450H, LC500H,
LS500H, NX300H, RX450H

ADDITIONAL INFORMATION

Introduction

Hybrid vehicles are equipped with 2 types of batteries:


Hybrid Vehicle (HV) battery



12-volt auxiliary battery

If the vehicle is put into storage, the State-Of-Charge (SOC) of its HV battery and auxiliary battery
will gradually decrease. To prevent the auxiliary battery from becoming discharged during storage,
proper maintenance is necessary.
Perform the following maintenance service for the HV battery and 12-volt auxiliary battery.
NOTE
Before disconnecting the auxiliary battery, confirm the shift lever is in the “P” position and
apply the parking brake completely. The shift lever cannot be shifted from the “P” position
with the 12-volt auxiliary battery disconnected.
If the negative (–) terminal of the auxiliary battery is reconnected, even if the power switch is
selected to the “START” mode, the hybrid system may NOT start. In this case, push the
POWER switch to select “START” again to start the hybrid system (the “READY” light is ON).
If the hybrid system still does NOT start (the “READY” light is OFF), refer to the Repair Manual.
If the vehicle is equipped with VGRS, the system must be initialized after the auxiliary battery
has been reconnected. Refer to the applicable vehicle specific Service Bulletin for instructions.

© 2017 Lexus, a division of Toyota Motor Sales, USA

Page 1 of 6

L-SB-0107-17

January 30, 2017

Page 2 of 6

Maintenance for HV & Auxiliary Batteries
Maintenance Items
CONDITION*

MAINTENANCE OPERATION

Fully charge the 12-volt auxiliary battery. Fast charge is NOT
recommended on the 12-volt battery in order to prevent battery
damage. (Deliver the vehicle to the customer after it is fully
charged to 12.6 V.)

Before Delivery

To Store for 30 Days or More

Just After Unloading & Every 2 Months

Disconnect the negative (–) terminal of the 12-volt auxiliary
battery to prevent the SOC of the auxiliary battery from
decreasing during storage due to parasitic current.
Keep the Hybrid System ON for 30 minutes with the transmission
in the “P” position (in order to charge the HV battery and the
auxiliary battery).

*The condition also corresponds with the section titles within this Service Bulletin.

Warranty Information
OP CODE

DESCRIPTION

TIME

OFP

T1

T2

N/A

Not Applicable to Warranty

–

–

–

–

Required Tools & Equipment
SPECIAL SERVICE TOOLS (SST)

PART NUMBER

QTY

GR8 Battery Diagnostic Station**

00002-MCGR8

1

* Essential SST.

NOTE
Additional SSTs may be ordered by calling 1-800-933-8335.

Before Delivery

1. Before charging the auxiliary battery, turn OFF ALL lights and accessories.
2. Locate the 12-volt auxiliary battery.

© 2017 Lexus, a division of Toyota Motor Sales, USA

L-SB-0107-17

January 30, 2017

Page 3 of 6

Maintenance for HV & Auxiliary Batteries
Before Delivery (Continued)

3. Remove the positive (+) terminal cover

Figure 1.

1

Positive (+) Terminal Cover

4. Check the battery SOC.


If the battery voltage is LESS THAN 12.6 V, then continue to step 5.



If the battery voltage is 12.6 V or MORE, replace the positive (+) terminal, close the battery
cover, install the luggage compartment floor mat, and close the trunk.
CAUTION
If measuring the voltage with the negative (–) terminal connected, verify IG/OFF, and turn
headlights ON for 60 seconds or more. This removes the surface charge.

5. Test the 12-volt auxiliary battery using the

Figure 2. GR8 Battery Diagnostic Station

GR8 Battery Diagnostic Station. If charging
is required, the GR8 will automatically start
to charge.
A. Connect the red charger clamp to the

positive (+) battery terminal and the
black charger clamp to the negative (–)
battery terminal.
B. Plug the charger into a grounded

110-volt outlet and flip the power
switch to the “ON” position.

© 2017 Lexus, a division of Toyota Motor Sales, USA

L-SB-0107-17

January 30, 2017

Page 4 of 6

Maintenance for HV & Auxiliary Batteries
Before Delivery (Continued)

C. Once the charger is properly turned ON, perform a diagnostic charge by “MODEL” (select
the appropriate vehicle model). The GR8 Battery Diagnostic Station will indicate results
when complete. If the battery tests bad (“Replace Battery”), replace the auxiliary battery.
NOTE
If the vehicle model is NOT listed in the model list, charge by battery stock code. To
charge by stock code, refer to the Lexus Battery Stock Number Chart located on the
Technical Information System (TIS), Diagnostics – Tools & Equipment –
Battery Diagnostics.
If the auxiliary battery was stored at 32ºF (0ºC) or below, charge the auxiliary battery in
a room above 32ºF (0ºC).

CAUTION
Charge in a well-ventilated area.
Do NOT allow sparks or fire near the auxiliary battery.

6. If the GR8 Battery Diagnostic Station is NOT available, you may charge the 12-volt battery by
turning the vehicle to “READY” ON.
 Run time will vary depending on the SOC.
 If this method is used, you MUST confirm that the battery is charged to 12.8 V using
a DVOM.

To Store for 30 Days or More
Disconnect the Negative (–) Terminal:

1. Turn OFF ALL lights and accessories.

Figure 3.

2. Disconnect the negative (–) terminal.
NOTE
When it is necessary to move the vehicle,
reconnect the negative (–) terminal.

1

Negative (–) Terminal Cover

© 2017 Lexus, a division of Toyota Motor Sales, USA

L-SB-0107-17

January 30, 2017

Page 5 of 6

Maintenance for HV & Auxiliary Batteries
Every Two Months
Cycle Vehicle to “READY” ON:
NOTE
When the remaining capacity of the HV battery is low, the gasoline engine automatically starts
and the HV battery is charged. The 12-volt auxiliary battery is also charged by the HV battery
regardless of the gasoline engine operation.
Be sure to reconnect the negative (–) terminal of the auxiliary battery before performing
this procedure.

1. Park the vehicle in open air or connect the exhaust extraction hose to the exhaust pipe.
2. Apply the parking brake.
3. With the brake pedal depressed, push the
POWER switch and check that the “READY”
light in the meter illuminates when the
hybrid system starts (the “READY” light
is ON).

Figure 4.

4. Turn OFF ALL lights and accessories.
5. Check that the shift lever is in the “P” position.

© 2017 Lexus, a division of Toyota Motor Sales, USA

L-SB-0107-17

January 30, 2017

Page 6 of 6

Maintenance for HV & Auxiliary Batteries
Every Two Months (Continued)
Cycle Vehicle to “READY” ON:

6. Keep the “READY” light ON and charge the
HV battery for 30 minutes.

Figure 5.
1

NOTE
2

If the amount of charging energy is
small, the display may NOT indicate
the energy flow.
Ensure there is a sufficient amount of
fuel for the vehicle to run for 30 minutes.

3

4
6

1

Energy Monitor

2

Engine

3

Battery

4

Electric Motor

5

Past Record

6

Consumption

© 2017 Lexus, a division of Toyota Motor Sales, USA

5