battery MERCEDES-BENZ B-CLASS HATCHBACK 2021 Owner's Guide

Tr
ailers with a 7-pin plug can be connected tothe
ve hicle with thefo llowing adap ters:
R Adapter plug
R Adapter cable
The trailer will be cor rectly de tected bytheve hi-
cle only if thefo llowing conditions are met:
R The trailer is connected cor rectl y.
R The trailer lighting system is in working order.
The functions of thefo llowing systems will be
a.ec tedbya cor rectly connected trailer:
R ESP ®
trailer stabilisation
R Active Lane Keeping Assist
R Parking Assist PARKTRONIC
R Active Parking Assist
R Blind Spot Assist or Active Blind Spot Assist
R Drive Away Assist
R Cross Tra1c Ale rt
R Reversing camera
R 360° camera Coupling up a tr
Coupling up a tr ailer
ailer
* NO
NOTE
TEDamage tothe star ter battery due
to full dis charge Charging
the trailer battery using the po wer
supply of the trailer can damage the star ter
batter y. #
Do not use theve hicle's po wer supply to
ch arge the trailer batter y. #
Remo vethe co ver cap from the ball head and
store it in a safe place. #
Position the trailer on a le vel sur face behind
th eve hicle and couple it up totheve hicle. #
Open the soc ket cap. #
Inse rtthe plug with lug 1ingroo ve 3 on
th e soc ket. #
Turn bayonet coupling 2totheright as far as
it will go. #
Let the cap engage. #
Secure the cable tothe trailer with cable ties
(only if you are using an adap ter cable). #
Make sure that the cable is alw ays slack for
ease of mo vement during cornering.
Under thefo llowing conditions, a message may
appear on the inst rument display even if the
trailer has been connec ted cor rectl y:
R LEDs ha vebeen ins talled in the trailer lighting
system.
R The cur rent has fallen below the trailer lighting
system's minimum cur rent (50 mA).
% Accessories can be connected tothe perma-
nent po wer supply up to180 W and tothe
po we r supply that is switched on via the igni-
tion loc k. 276
276
Driving and parking

F
F
unction of t
unction of t he pow
he power met
er meter (plug-in h
er (plug-in h ybr
ybrid)
id) 1
Combustion engine and electric mo tor
switched o.
2 Position in the display range of there co vered
energy
3 End of the display range of there co vered
energy
4 End of the display range of the combined out-
put of thehy brid system The
following functions of the po wer me ter are
per form ed:
R The po wer me ter supports you in electric-only
mode and displa ys the output obtained from
th ehy brid system.
R Regenerated energy is sh own in area 1–
3.
R When the po wer me ter needle is at position
1, theve hicle is switched o.. The combus-
tion engine and the electric mo tor are
switched o..
R Pow errange 3–4 show sth e combined
output of thehy brid system. F
F
unction of t
unction of t he electr
he electric mot
ic motor pow
or pow erav
er availability
ailability
displa
displa y (plug-in h
y (plug-in h ybr
ybrid)
id) 1
Start of the POWER display range
2 End of the POWER display range
3 Maximum recuperated energy
4 Start of the display range of there cuperated
energy
5 Current state of charge ofthe high-voltage
battery
R Area 1-2 shows th e output in electric
mode or boost mode. The POWER display sup-
ports you in electric-only mode.
R Area 3-4 shows th ere cuperated energy. 284 284
Instrument display and on-board computer

R
From point 3,the maximum recuperated
energy has been reached.
R The cur rent state of charge of high-voltage
battery 5is displa yed. Displa
Displa
ying t
ying the pow
he pow er met
er meter (plug-in h
er (plug-in h ybr
ybrid)
id)
On-board computer: 4 Content #
Select Power meter. Ov
Ov
er
ervie
vie w of display
w of display s in t
s in the ins
he ins tr
trument display
ument display
Displa yson the inst rument displa y:
u Active Parking Assist (/ page 269)
é Parking Assist PARKTRONIC deactivated
(/ page 267)
h Cruise control (/ page 232)
00CB Limiter (/ page 232)
ç Active Distance Assist DISTRONIC
(/ page 235)
00D4 Active Brake Assist (/ page 244) à
Active Steering Assist (/ page 241)
00B0 Active Lane Keeping Assist (/ page 255)
° Haptic accelerator pedal (/ page 179)
õ PLUG‑IN HYBRID operation activated
ò Sound generator inoperative (/ page 426)
00D6 ECO start/stop function (/ page 176)
00D9 HOLD function (/ page 228)
00CE Adaptive Highbeam Assist (/ page 143)
Ad aptive Highbeam Assist Plus
(/ page 144)
ð Maximum permissible speed exceeded (for
cer tain countries only)
V
V ehicles wit
ehicles wit h Speed Limit Assist:
h Speed Limit Assist: detected
instructions and tra1c signs (/ page 249).
V
V ehicles wit
ehicles wit h
hTr
Tra1c
a1c Sign Assist:
Sign Assist: detected instruc-
tions and tra1c signs (/ page 250). Head-up display
Head-up display
F
F
unction of t
unction of t he head-up display
he head-up display The head-up display projects
thefo llowing infor-
mation into the driver's /eld of vision abo vethe
cockpit, forex ample:
R The vehicle speed
R Information from the navigation system
R Information from the driving systems and driv-
ing saf ety sy stems
R Some warning messages
Depending on theve hicle's equipment, di.erent
content can be shown in theth re e areas of the
head-up displ ay (/page 286). Inst
rument display and on-board computer
285
285

tion about anti-theT pr
otection can be obtained at
a quali/ed specialist workshop. Home scr
Home scr
eenov
een overerview
view 1
Depending on the displa y,calls up the /rst
th re e applications or the home screen
2 Calls up the pro/le
3 Calls up the global sear ch 4
SOS NOT REA DY(only when the Mercedes-
Benz emer gency call system is not available)
5 Mercedes me connect active
6 Transmission of vehicle position active 7
Signal st rength of the mobile phone networ k,
network displa y,battery status of the mobile
phone connected, time
8 Calls up theNo ti/cations Cent re
9 Calls up an application using the symbol MBUX multimedia system
289
289

#
Select Maximum ,8 amps or6 amps .
When the battery is charge d, thech arging cur-
re nt is limi tedto the selected amperage.
% For saf etyre asons, only use thech arging
cable supplied with theve hicle or an original
Mercedes-Benz charging cable. Mercedes-
Benz thoroughly tests these original charging
cables forth eir suitability forth e high-voltage
ch arging of your vehicle. Pur chase these parts
from your Mercedes-Benz Service Centre and
obtain advice there.
A
A ctiv
ctiv ating or deactiv
ating or deactiv ating r
ating rout
oute-based oper
e-based oper ating
ating
mode s
mode str trat
at egy
egy #
Select Electric in city .
Depending on the pr evious status, the func-
tion is activated or deactivated. Calling up t Calling up t
he ener
he energy
gy0ow
0ow display
display Multimedia system:
4 © 5
EQ #
Select Energy flow.
The visualisation of the energy 0ow in theve hi-
cle is displ ayed. In addition
tothe energy 0o w,information on the
status of thehy brid system and the cur rent state
of charge ofthe high-voltage battery is also dis-
pla yed. F F
unctions of t
unctions of t he ener
he energy
gy0ow
0ow display
display 1
State of charge ofthe high-voltage battery
2 Combustion engine
3 Energy 0ow
4 High-voltage battery
5 Status of thero ute-based operating-mode
strategy (/ page 181) The active components of
thehy brid system are
highlighted in the energy 0ow displa y.The energy
0ow between the individual components is shown
in colour.
The energy 0ow is shown in di.erent colours
depending on the operating status:
R Whit
Whit e: e:constant energy 0ow
R R
Red:
ed: high energy 0ow (boost e.ect)
R Gr
Green:
een: low- emission energy 0ow in the case of
re cuperation, elect ric mode and when charg-
ing the high-voltage battery N
N
a
avig
vig ation
ation N
No
ot
tes on na
es on na vig
vigation
ation R
R
out
out e guidance wit
e guidance wit h augment
h augmented r
ed reality
eality &
W
WARNING
ARNING Risk of accident and injury as a
re sult of distraction, inco rrect depiction or
wrong interpr etation of the display
The camera image of the augmented reality
displ ayis not suitable as a guide for driving. 302
302
MBUX multimedia system

T
T
elephone menu ov
elephone menu overerview
view 1
Blue tooth ®
device name of the cur rently con-
nected mobile phone/of the mobile phone
2 Blue tooth ®
device name of the cur rently con-
nected mobile phone/of the mobile phone
(two phone mode)
3 Battery status of the connected mobile phone
4 Signal strength of the mobile phone network
5 Options 6
Device manager
7 Messages
8 Numerical pad
9 Contact sear ch T
T elephon
elephon y oper
y operating modes ov
ating modes overerview
view
Depending on your equipment, thefo llowing tel-
ephony operating modes are available:
R A mobile phone is connected tothe multime-
dia system via Blue tooth ®
. MBUX multimedia system
313
313

th
e emer gency call and faster transfer of the
accident data.
Measu resfo rre scue, reco very or towing away
can then be initiated in quickl y.
R With a Mercedes-Benz emer gency call, the
accident data is only transfer redto the public
coordination centre with the appr oval of the
cus tomer.
In theev ent of an automatically triggered
emer gency call in which there is no voice con-
ta ct, the accident data is transmitted immedi-
ately tothe public emer gency call centre.
R Should the Mercedes-Benz emer gency call
centre not be available, the 112 emer gency
call is ca rried out automaticall y.Ov Ov
er
ervie
vie w of emerg
w of emerg ency call syst
ency call syst ems
ems Bo
th th e Mercedes-Benz emer gency call system
as well as the 112 emer gency call system (EU
eCall) can help toreduce the time between an
accident and the ar riva l of emer gency services at
th e site of the accident. They help locate an acci-
dent site in places that are di1cult toaccess. Bo
th emer gency call systems can initia tean emer-
ge ncy call automatically (/ page 325) or man-
ual ly ( / page 326).
Only make emer gency calls if you or others are in
need of rescue. Do not make an emer gency call in
th eev ent of a breakdown or a similar situation.
Messag
Messag es on t
es on the display
he display
The following message s appear inthe display of
bo th emer gency call systems:
R SOS NOT READY: theve hicle is not switched
on or the emer gency call system is malfunc-
tioning. This does not necessarily indicate
comple tefailure of the emer gency call system.
Eme rgency calls call still be transmitted.
The display only refers to theve hicle and does
not take account of theav ailability of mobile
phone networ ksand the Mercedes-Benz emer-
ge ncy call centre.
The functional readiness of the emer gency call
system on theve hicle can be seen when the
SOS NOT READY displaydisappears once the
ve hicle is switched on. R
0053: The icon appears in the display during
an active emer gency call.
% Ifth ere is a malfunction in the emer gency call
system (e.g. a fault with the speaker, micro-
phone, airbag, SOS button), a cor responding
message appears on the inst rument displa y. T T
r
r igg
igg er
ering an aut
ing an aut omatic emerg
omatic emerg ency call
ency call R
R
eq
eq uir
uir ements:
ements:
R The vehicle is switched on.
R The star ter battery is su1ciently charge d.
Bo th th e Mercedes-Benz emer gency call system
as well as the 112 emer gency call system (EU
eCall) automatically initia tean emer gency call
aTer:
R Activation of there straint systems su chas air-
bags or seat belt tensioners aTer an accident
The eme rgency call has been made:
R Avo ice connection is established with the
emer gency call centre. MBUX multimedia system
325
325

Fo
r accident clari/cation purposes, thefo llowing
measures can be take n up toan hour aTer the
emer gency call has been initia ted:
R The cur rent vehicle position can be de ter-
mined.
R Avo ice connection totheve hicle occupants
can be es tablished.
R Emer gency call data can be called up.
% ForRu ssia: various functions, e.g. receiving
tra1c information, cannot be per form ed for
up totwo hours aTer sending an emer gency
call. Self diagnosis function of t
Self diagnosis function of t
he emerg
he emerg ency call sy
ency call sy s-
s-
t
t em
em Yo
ur car veri/es the operability of the emer gency
call system each time theve hicle is ON. In case of
system failure, you will be informed with text mes-
sage on the inst rument clus ter and with red indi-
cator SOS NOT READY on the displa y.
Please, ma kesure, that during 30 seconds aTer
switching vehicle ON there d indicator SOS NOT
READY in the upper right corner of display is switched OFF,
this means the emer gency call sys-
te m passed diagnostics successfull y. S
S
t
tar
ar ting/ending ERA
ting/ending ERA -GL
-GLON
ONASS t
ASS t es
est mode
t mode R
R
eq
eq uir
uir ements:
ements:
R The star ter battery is su1ciently charge d.
R The vehicle is switched on.
R The vehicle has been stationary for at least
one minute.
% The test mode is cu rrently available in thefo l-
lowing countries, forex ample:
R Russia
R Belarus
R Kazakhstan
R Armenia
R Kyrgyzs tan #
T
To st
o st ar
art t
t t he t
he t es
est mode:t mode: press and hold the
0076 button on the multifunction steering
wheel for at least /ve seconds.
The test mode is star ted and automatically
ends aTer the language test has been pe r-
fo rm ed. #
T
To st
o st op manual t
op manual t es
est mode:t mode: switch o. theve hi-
cle.
The test mode is ended. Inf Inf
or
ormation on dat
mation on dat a pr
a processingocessing Pr
Processing of per
ocessing of per sonal dat
sonal data via t
a via the Mer
he Mercedes- cedes-
Benz emerg
Benz emerg ency call sy st
enc y call sy stem
em
All processing of pe rsonal data via the Mercedes-
Benz emer gency call system cor responds with the
speci/cations in the EU Regulation 2016/679 "on
th e pr otection of individuals with rega rd tothe
processing of personal data (GDPR)".
The data is solely used bythe Mercedes-Benz
emer gency call system forre scue and reco very in
th eev ent of an accident.
The owner of a vehicle, that is equipped with a
Mercedes-Benz emer gency call system in addition
to the 112 emer gency call system (EU eCall), has 328 328
MBUX multimedia system

R
Frequent operation in mountainous terrain or
on poor road sur faces
R When the engine is oTen leT idling for long
periods
R Operation in particular lydusty conditions
and/or if air-recirculation mode is frequently
used
In these or similar operating conditions, ha vethe
interior air /lter, air /lter, engine oil and oil /lter,
fo rex ample, changed more frequentl y.The tyres
must be checked more frequently if theve hicle is
operated under increased loads. Further informa-
tion can be obtained at a quali/ed specialist work-
shop. Batt Batt
er
ery disconnection per
y disconnection per iods
iodsThe AS
SYST PLUS service inter val display can cal-
culate the service due date only when the battery
is connected. #
Display and no tedown the service due date
on the inst rument display before disconnect-
ing the battery (/ page 336). Engine com
Engine com
par
partment
tment A
A
ctiv
ctiv e bonne
e bonne t (pedes
t (pedestr trian pr ot
ian pr otection)
ection) Oper
Oper
ation of t
ation of t he activ
he active bonne
e bonne t (pedes
t (pedestr trian pr ot
ian pr otec-
ec-
tion)
tion)
In cer tain accident situations, the actuation of the
active bonnet reduces therisk of injury topedes-
trians. The rear area of the bonnet is raised by
appr oximately 70 mm.
Fo rth e drive tothewo rkshop, reset the actuated
active bonnet yourself (/ page 337).
ATer the active bonnet has been actuated, pedes-
trian pr otection may be limited.
Ha ve the full functionality of the active bonnet
re stored in a quali/ed specialist workshop.
R
R ese ese tting t
tting t he activ
he activ e bonnet
e bonnet &
W
WARNING
ARNING Risk of burns from hot compo-
nent parts in the engine compartment
Cer tain component parts in the engine com-
partment can be very hot, e.g. the engine, the
cooler and parts of theex haust system. #
Allow the engine tocool down and only
to uch component parts described in the
fo llowing. #
With your hand 0at, push down active bonnet
1 inthe area around the hinges on bo th
sides (ar rows ).
In doing so, the actuator is depressurised and
yo u may hear a hissing sound.
The engine bonnet must engage in position. #
Ifth e active bonnet can be raised slightly at
th ere ar in the area of the hinges, repeat the
step until it engages co rrectl y. Maintenance and ca
re
337
337

Batt
Batt
er
ery (v
y (v ehicle)
ehicle) N
No
ot
tes on t
es on t he 12 V batt
he 12 V batt ery
ery &
W
WARNI NG
ARNI NGRisk of explosion due toelec-
trostatic charge
Electrostatic charge can ignite the highly
ex plosive gas mixtu reinthe batter y. #
Todischar geany elect rostatic charge
th at may ha vebuilt up, touch the me tal
ve hicle body before handling the batter y. The high
ly0ammable gas mixtu reis created while
th e battery is charging and during starting assis-
ta nce. &
W
W ARNI NG
ARNI NGDanger of chemical burns from
th e battery acid
Battery acid is caustic. #
Avoid contact with the skin, eyes or
clo thing. #
Do not lean overth e batter y. #
Do not inhale battery gases. #
Keep children away from the batter y. #
Immediately rinse bat tery acid o. thor-
oughly with plenty of clean water and
seek medical attention immediatel y. +
ENVIR
ENVIR
ONMENT
ONMENT AL NO
AL NOTE
TEEnvironmen tal
damage due toimproper disposal of bat-
te ries Batteries contain pollutants. It is
illegal todispose of them with the household
ru bbish. #
Dispose of batteries in an
environmentally responsible manner.
Ta ke dischar ged batteries toaqu ali/ed
specialist workshop or toa collection
point for used batteries. If
yo u ha vetodisconnect the 12 V batter y,con-
ta ct a quali/ed specialist workshop.
Comply with saf ety no tes and take protective
measures when handling batteries. Risk of
explosion. Fire
, naked 0ames and smoking are
prohibi ted when handling the batter y.
Av oid creating spar ks. Electrolyte or battery acid is cor
rosive.
Av oid contact with the skin, eyes or
clo thing. Wear suitable pr otective
clo thing, in particular glo ves, an apron
and a face mask. Immediately rinse
electrolyte or acid splashes o. with
clean water. Consult a doctor if neces-
sar y. We
ar saf ety glasses. Breakdown assis
tance
361 361