Get Checking and Filling -> Battery(agm battery) Guide for Audi S Q5 SUV Third Generation (2025-2026)

Checking and Filling

Audi dealer or authorized Audi Service Fa-

cility for assistance.

even if the ignition is turned off, which in-

creases the risk of injury.

– Applies to: coolant expansion tank for com-

bustion engine: if there is too much coolant

in the expansion tank after adding coolant,

drive to an authorized Audi dealer or author-

ized Audi Service Facility as soon as possible

to have the coolant level corrected.

– Using non-distilled water increases the risk

of engine damage. Its chemical components

may cause significant corrosion damage in

the engine.

– Coolant additive and coolant can be danger-

ous to your health. For this reason, store the

coolant in the original container and away

from children. There is a risk of poisoning.

WARNING

Applies to: vehicles with plug-in hybrid drive

The sealed cap on the high-voltage system

coolant expansion tank must only be opened

or filled by an authorized Audi dealer or au-

thorized Audi Service Facility.

– If you had to add a large amount of non-dis-

tilled water (more than 0.5 liter), then im-

mediately drive to an authorized Audi dealer

or authorized Audi Service Facility to have

the coolant changed.

– The cap of the coolant expansion tank for

the high-voltage system is equipped with a

seal that must never be removed under any

circumstances ðpage 253, fig. 168. If the

coolant expansion tank for the high-voltage

system is not sealed, please contact an au-

thorized Audi dealer or authorized Audi

Service Facility.

Brake fluid

– When adding coolant, it may leak into the

inside of high-voltage components and

cause a short circuit, increasing the risk of

fire.

Note

Coolant loss that results in the coolant expan-

sion tank becoming nearly empty primarily in-

dicates that there are significant leaks in the

cooling system, which can lead to further

damage.

Fig. 172 Engine compartment: cap on brake fluid reservoir

Observe the safety precautions ðpage 250, Gen-

eral information.

– Applies to: coolant expansion tank for com-

bustion engine: Do not add coolant if the ex-

pansion tank is empty. Air could enter the

cooling system and increase the risk of dam-

age. If this is the case, do not continue driv-

ing. See an authorized Audi dealer or au-

thorized Audi Service Facility for assistance.

– Applies to: coolant expansion tank for com-

bustion engine: If there is any coolant re-

maining, add additional coolant. Drive to an

authorized Audi dealer or authorized Audi

Service Facility immediately to have the

malfunction corrected. If the  indicator

light turns on again, do not continue driving

and turn off the ignition. See an authorized

Checking the brake fluid level

The brake fluid reservoir is located under a cover

on the driver’s side.

►

Park the vehicle on a level surface.

►

Lift the cover ðpage 253, fig. 168 at both

openings and remove it.

►

Read the brake fluid level on the brake fluid

reservoir ðpage 253, fig. 168. The brake fluid

level must be between the MIN and MAX mark-

ings ð

The brake fluid level is monitored automatically.



260

Checking and Filling

Messages

Note

The following messages may appear, depending

on the vehicle equipment:

– If the brake fluid level is above the MAX

marking, brake fluid may leak out over the

edge of the reservoir and result in damage

to the vehicle.

 /  Brakes: stop vehicle and check brake

fluid level

– Do not allow any brake fluid to come into

contact with the vehicle paint, because it

will corrode the paint.

Stop the vehicle and check the brake fluid level.

See an authorized Audi dealer or authorized Audi

Service Facility for assistance.

Changing the brake fluid

Electrical system

Brake fluid should be changed at regular inter-

vals. Have the brake fluid changed by an author-

ized Audi dealer or authorized Audi Service Facili-

ty. The authorized Audi dealer or authorized Audi

Service Facility will inform you of the replace-

ment intervals.

The following messages may appear, depending

on the vehicle equipment:





If the

indicator light turns on,

there is a malfunction in the power supply, the

battery, or the vehicle electrical system.





Electrical system: malfunction! Safely

WARNING

stop vehicle

– If the brake fluid level is below the MIN

marking, it can impair the braking effect and

driving safety, which increases the risk of an

accident. Do not continue driving. See an au-

thorized Audi dealer or authorized Audi

Service Facility for assistance.

Safely stop your vehicle, do not continue driving,

and turn off the ignition ð . See an authorized

Audi dealer or authorized Audi Service Facility for

assistance.



Electrical system: malfunction! Restart not

– If the brake fluid is old, bubbles may form in

the brake system during heavy braking. This

could impair braking performance and driv-

ing safety, which increases the risk of an ac-

cident.

possible. Please contact Service

If you turn off the ignition, you will not be able to

restart the vehicle. Vehicle functions or driving

stability may be limited. Drive to an authorized

Audi dealer or authorized Audi Service Facility im-

mediately.

– The brake fluid in your vehicle must meet

the standard VW 501 14 and is available at

an authorized Audi dealer or authorized

Audi Service Facility. If this brake fluid is not

available, another high-grade brake fluid of

equivalent quality may be used, and it must

meet the U.S. Federal Motor Vehicle Stand-

ard (FMVSS) 116 DOT 4, Class 6.



Electrical system: malfunction! Please con-

tact Service

Turn off all electrical equipment that is not need-

ed. If necessary, some equipment will be turned

off automatically. Vehicle functions or driving

stability may be limited. Drive to an authorized

Audi dealer or authorized Audi Service Facility im-

mediately.

– Reusing brake fluid or using brake fluid that

is not permitted for your vehicle will signifi-

cantly impair the braking performance and

can even result in a failure of the brake sys-

tem. The manufacturer of the vehicle is not

liable for failures or damage resulting from

this. It will also not be covered by the war-

ranty.



Electrical system: low battery charge. Bat-

tery will be charged while driving

The starting ability may be impaired.

– If this message turns off after a little while, the

vehicle battery has charged enough while driv-

ing.



261

Checking and Filling

– If the message does not turn off, drive immedi-

ately to an authorized Audi dealer or authorized

Audi Service Facility to have the malfunction

corrected.

Even when electrical equipment is turned off, the

equipment can still drain the battery if the vehi-

cle is not driven for long periods of time. Deep

draining results in a chemical reaction that de-

stroys the inside of the battery. The battery must

be charged every month to prevent this

ðpage 265. Contact an authorized Audi dealer or

authorized Audi Service Facility for more infor-

mation.

WARNING

When there is an electrical system malfunc-

tion, vehicle functions may not work and driv-

ing stability may be limited, which increases

the risk of an accident. Do not continue driv-

ing and turn off the ignition. See an author-

ized Audi dealer or authorized Audi Service Fa-

cility for assistance.

Winter operation

Cold weather places an especially high load on

the 12 volt vehicle battery. Have the battery

checked by an authorized Audi dealer or author-

ized Audi Service Facility before cold weather be-

gins.

Battery

Battery general information

Replacing the battery

Applies to: 12 volt vehicle battery

Because of the complex power supply, all work

on batteries such as disconnecting, replacing,

etc., should only be performed by an authorized

Audi dealer or authorized Audi Service Facility

All work on the battery must only be performed

by an authorized Audi dealer or authorized Audi

Service Facility.

The 12 volt vehicle battery was developed based

on the installation location and is equipped with

safety features. If a 12 volt vehicle battery must

be replaced, ask an authorized Audi dealer or au-

thorized Audi Service Facility about the electro-

magnetic compatibility, size, and the necessary

maintenance, power, and safety standards for

the new 12 volt vehicle battery. The battery vent

on the 12 volt vehicle battery must always be on

the negative terminal side. The battery vent on

the positive terminal side must always be closed.

Multiple batteries with different technologies

may be installed in your vehicle:

– Vehicle battery (for example, for starting the

engine, basic power supply) ðpage 263, Safety

precautions

– Auxiliary battery (for example, for recuperation

or optional equipment) ðpage 263, Safety pre-

cautions

– Plug-in hybrid drive: High-voltage battery (for

example, for electric driving) ðpage 123, In-

troduction.

When replacing the 12 volt lead-acid vehicle bat-

tery, only use a maintenance-free 12 volt lead-

acid battery that conforms to the TL 825 06 and

VW 7 50 73 standards. These standards must be

from October 2014 or newer.

Not running the vehicle for long periods of

time

The battery will gradually drain if the vehicle

does not run for long periods of time. To ensure

that the vehicle can still be started, the electrical

equipment will be limited or turned off. Some

convenience functions, such as interior lighting

or power seat adjustment, may not be available

under certain circumstances. The convenience

functions will be available again when you start

the engine.

WARNING

– All work on the battery or electrical system

in your vehicle can result in injuries, chemi-

cal burns, accidents, or burns. Because of

this, all work must be performed only by an

authorized Audi dealer or authorized Audi

Service Facility.



262

Checking and Filling

instrument cluster until the temperature re-

turns to normal.

– Always have an authorized Audi dealer or

authorized Audi Service Facility replace the

12 volt vehicle battery, because an adapta-

tion must be performed on the vehicle elec-

trical system when the battery is replaced.

Only an authorized Audi dealer or author-

ized Audi Service Facility has the necessary

technology to perform the adaption correct-

ly. Otherwise, there could be a loss of safe-

ty-related functions among other things,

which increases the risk of an accident.

– Using a 12 volt vehicle battery that does not

match the same specifications and dimen-

sions as the factory-installed 12 volt vehicle

battery can result in short circuits or cause a

fire. Serious injuries or death may result.

– Only use maintenance-free and leak-proof

12 volt vehicle batteries that match the

same specifications and dimensions as the

factory-installed 12 volt vehicle battery.

– Never connect a charging cable or jump

start cable directly to the 12 volt vehicle

battery. Only use the connections in the en-

gine compartment ðpage 265.

– Always have an authorized Audi dealer or

authorized Audi Service Facility replace the

12 volt vehicle battery, because an adapta-

tion must be performed on the vehicle elec-

trical system when the battery is replaced.

Only an authorized Audi dealer or author-

ized Audi Service Facility has the necessary

technology to perform the adaption correct-

ly.

– Using a vehicle battery that does not meet

the AUDI AG quality specifications or with a

capacity that is too low will void the vehi-

cle’s certification for use on public roads,

and this will void the vehicle registration

For the sake of the environment

 Batteries and electrical/electronic devices

must be disposed of in an environmentally

safe manner ðpage 322, Disposal instruc-

tions.

Safety precautions

WARNING

California Proposition 65 Warning:

Explanation of warning symbols:

– Battery posts, terminals and related acces-

sories contain lead and lead compounds,

chemicals known to the State of California

to cause cancer and reproductive harms.

Wash hands after handling.

Observe all warnings - there is a risk for in-



/ Always follow the instructions in the Own-

jury!



er’s Manual.

12 volt vehicle battery. Energized compo-

nents. Improper handling can result in

short circuits ð in Battery general in-

formation on page 262.

Note



– If the vehicle will be parked for long periods

of time, protect the 12 volt vehicle battery

against the cold so that it will not “freeze”

and become damaged ðpage 265, Charg-

ing the 12 volt vehicle battery.

With the exception of charging the 12 volt

vehicle battery and jump starting, all oth-

er procedures involving the 12 volt vehicle

battery must be performed by an author-

ized Audi dealer or authorized Audi Serv-

ice Facility ð in Battery general infor-

mation on page 262 ð in Battery gen-

eral information on page 263.

– There are electrical components under the

cargo floor behind a trim panel that warm

up during operation. To reduce the risk of

the components overheating, do not store

objects such as blankets under the cargo

floor. If the components overheat, they will

turn off temporarily. This will be indicated

by a message that will be displayed in the





263

Checking and Filling

High voltage! The voltage in the high-volt-

age system is high enough to cause fatal

injuries. Touching damaged high-voltage

components can result in a fatal electric

Applies to: high-voltage battery: Handling

the high-voltage battery incorrectly can

result in serious injuries or death. The

high-voltage battery must only be serv-

iced by qualified and trained technicians.

Never make modifications to the high-

voltage battery. If the high-voltage bat-

tery is open, it must not come into contact

with water or other liquids. Liquids may

cause short circuits, electric shocks, and

burns.

Have the high-voltage battery replaced

only by an authorized Audi dealer or au-

thorized Audi Service Facility. Audi recom-

mends an authorized Audi dealer or au-

thorized Audi Service Facility, because

these locations have trained personnel

and the required parts and tools.









shock.

Electrolyte fluid is highly corrosive. Always

wear protective gloves and eye protection.



First aid: if electrolyte fluid enters the

eyes, immediately flush with clean water

for several minutes. Seek medical atten-

tion immediately. Immediately neutralize

electrolyte fluid on the skin or clothing us-

ing a soap solution and rinse with plenty

of water. Seek medical attention immedi-

ately if electrolyte fluid is ingested.

 ^{Always wear eye protection.}

If electrolyte fluid enters the eyes, imme-



diately flush with clean water for several

minutes. Seek medical attention immedi-

ately.

WARNING

All work on the batteries must only be per-

formed by an authorized Audi dealer or au-

thorized Audi Service Facility.

Fire, sparks, open flame, and smoking are

prohibited. Avoid creating sparks and

short circuits when handling cables and

electrical devices.



– Gases that escape from these batteries can

be poisonous or flammable.

– The contents of these batteries can be corro-

sive. If any battery contents come into con-

tact with the skin, flush the affected area

with clean water for at least 15 minutes.

Then wash the affected area with soap. Have

the affected area examined by a medical

professional.

The high-voltage battery is flammable.

The high-voltage battery must never be

exposed to fire, sparks, or open flame. Al-

ways handle the high-voltage battery with

care to reduce the risk of damage and

leaking fluids.



Always keep children away from battery



electrolyte fluid and the battery.

Note

A highly explosive mixture of gases can

Applies to: mild hybrid drive





form when charging batteries.

– Components must not be connected to the

battery terminals and wires on the 48 volt

battery because this increases the risk of

damage, for example due to overvoltage.

– Have maintenance work performed only by

trained personnel.

Applies to: high-voltage battery: Handling

the high-voltage battery incorrectly can

result in serious injuries or death. Never

remove the cover from the high-voltage

battery and never disassemble the high-

voltage battery.

– Have the 48 volt lithium battery replaced

only by an authorized Audi dealer or author-

ized Audi Service Facility. Audi recommends

an authorized Audi dealer or authorized

Audi Service Facility, because these loca-

tions have trained personnel and the re-

quired parts and tools.



264

Checking and Filling -> Battery(agm battery) for Your Audi S Q5 SUV Third Generation (2025-2026)

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