Get Checking and Filling -> Battery Guide for Audi A5 4 Door Third Generation (2025-2026)

Checking and Filling

Not running the vehicle for long periods of

time



Electrical system: malfunction! Please con-

tact Service

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.

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.



Electrical system: low battery charge. Bat-

tery will be charged while driving

The starting ability may be impaired.

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 251. Contact an authorized Audi dealer or

authorized Audi Service Facility for more infor-

mation.

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

vehicle battery has charged enough while driv-

ing.

– 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.

WARNING

Winter operation

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.

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.

Replacing the battery

Applies to: 12 volt vehicle battery

Battery

All work on the battery must only be performed

by an authorized Audi dealer or authorized Audi

Service Facility.

Battery general information

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

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 250, Safety

precautions

– Auxiliary battery (for example, for recuperation

or optional equipment) ðpage 250, Safety pre-

cautions

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



249

Checking and Filling

VW 7 50 73 standards. These standards must be

from October 2014 or newer.

and become damaged ðpage 251, Charg-

ing the 12 volt vehicle battery.

– 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

instrument cluster until the temperature re-

turns to normal.

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.

– 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 251.

– 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 310, Disposal instruc-

tions.

Safety precautions

WARNING

Explanation of warning symbols:

California Proposition 65 Warning:

– 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 250.

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”



250

Checking and Filling

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 250 ð in Battery gen-

eral information on page 250.

Note

Applies to: mild hybrid drive

– 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.



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.

– 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.



– Never try to replace the 48 volt lithium bat-

tery yourself. The 48 volt lithium battery in

this vehicle may only be replaced with a 48

volt lithium battery designed by Audi specif-

ically for this vehicle. Using other 48 volt

lithium or lead batteries will result in con-

siderable malfunctions or even total failure

of the electrical system.

 ^{Always wear eye protection.}

If electrolyte fluid enters the eyes, imme-



diately flush with clean water for several

minutes. Seek medical attention immedi-

ately.

– Never make modifications to the lithium

battery.

Fire, sparks, open flame, and smoking are



prohibited. Avoid creating sparks and

short circuits when handling cables and

electrical devices.

– Never open the 48 volt battery.

Charging the 12 volt vehicle battery

Always keep children away from battery



electrolyte fluid and the battery.

A highly explosive mixture of gases can



form when charging batteries.

WARNING

All work on the batteries must only be per-

formed by an authorized Audi dealer or au-

thorized Audi Service Facility.

– Gases that escape from these batteries can

be poisonous or flammable.

Fig. 166 Engine compartment: connectors for a charger or

jump start cables

– 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.

Observe the safety precautions ðpage 237, Gen-

eral information, ð

in Battery general infor-

mation on page 250 and ð

Requirement: only use chargers with a maximum

charging current of 14.8 volts. The battery ca-

bles remain connected.



251

Checking and Filling

The charging cable connections are located in the

Tips

engine compartment. The ground point

ways located on the vehicle body.

–

is al-

Read all of the manufacturer's instructions

for the charger before charging the battery.

►

Turn off the ignition and all electrical equip-

ment.

Windshield washer

system

►

Open the hood ðpage 239.

Press the release lever on the positive terminal

and fold the cover upward ðfig. 166.

Clamp the terminal clamps on the charger cor-

►

rectly onto the positive terminal

and the

ground point – .

►

Insert the power cable for the charger into the

socket and turn on the charger.

Keep the hood completely open during the

charging session ð

At the end of the charging session, turn off the

charger and pull the power cable out of the

socket.

Fig. 167 Engine compartment: washer fluid reservoir cap

►

Remove the charger terminal clamps.

Close the cover on the positive terminal.

Close the hood ðpage 239.

Observe the safety precautions ðpage 237, Gen-

eral information.

The windshield washer fluid reservoir  contains

the cleaning solution for the windshield and the

headlight washer system* ðpage 240. The reser-

voir capacity can be found in ðpage 308.

WARNING

– Never use charging equipment that is un-

suitable, visibly damaged, and/or dirty.

Check the charging equipment for damage

before every use.

To reduce the risk of lime scale deposits on the

spray nozzles, use clean water with low amounts

of calcium. Always add window cleaner to the wa-

ter. When the outside temperatures are cold, an

anti-freezing agent should be added to the water

so that it does not freeze.

– 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 251.

– A highly explosive mixture of gases can form

when charging batteries. Only charge the

battery in well-ventilated areas.

Messages

The following messages may appear, depending

on the vehicle equipment:

– A drained battery can freeze at tempera-

tures around 32 °F (0 °C). Do not charge or

use a frozen or thawed battery. If ice forms,

the battery housing can crack and battery

electrolyte fluid can leak, which increases

the risk of an explosion and chemical burns.

Contact an authorized Audi dealer or author-

ized Audi Service Facility for more informa-

tion.



Please add washer fluid

Fill the washer fluid for the windshield washer

system and the headlight washer system* when

the ignition is turned off.

Note

– The concentration of anti-freezing agent

must be adjusted to the vehicle operating

conditions and the climate. A concentration

that is too high can result in vehicle dam-

age.

– Leave the hood open while the 12 volt vehi-

cle battery is charging. If the hood is closed,

it could cause an electrical short circuit,

which increases the risk of fire.



252

Checking and Filling -> Battery for Your Audi A5 4 Door Third Generation (2025-2026)

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