ISO/SAE 12906:2024

International
Standard
ISO/SAE 12906
First edition
Road vehicles — Test procedures
2024-12
for electric vehicles to determine
charging performance
Véhicules routiers — Procédures d'essai des véhicules électriques
pour déterminer les performances de charge
Reference number
© ISO/SAE International 2024
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© ISO/SAE International 2024 – All rights reserved
ii
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Abbreviated terms . 3
5 General . 3
6 Test cases and general requirements . 4
6.1 Overview of test cases .4
6.2 General requirements .4
6.2.1 Vehicle manufacturer specifications .4
6.2.2 EV run-in.5
6.2.3 Measurement tolerances and accuracies .5
6.2.4 Determination of indicated SOC .5
6.2.5 Determination of recharged electric range by recharged energy . .6
6.2.6 Determination of charging efficiency .8
6.2.7 Determination of maximum charging power .9
6.3 Test procedures .10
6.3.1 Test procedure for test case Normal Charge .10
6.3.2 Test procedure for test case Fast Charge .11
7 Vehicle operator information . 14
Annex A (informative) Fast Charge at low ambient temperature .15
Annex B (informative) Heavy duty vehicles. 19
Bibliography .23

© ISO/SAE International 2024 – All rights reserved
iii
Foreword
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© ISO/SAE International 2024 – All rights reserved
iv
Introduction
The test procedures were derived from typical use cases. Both test procedures and use cases were
established based on the following premises:
— Comparability: the charging performance determined according to this document enables a comparison
of the performance of different electrically propelled vehicles in realistic scenarios. The application of
specific optimizing features to improve the charging performance (e.g. battery thermal preconditioning
based on navigation systems) is taken into account.
— Imitability and plausibility: the possibility to retrace the determined charging performance in principle.
— Reproducibility: the specified test conditions, test methods and test processes ensure reproducibility
within common measurement tolerances. It was important to leave as little space as possible for
inadvertent deviations or manipulations.
The test results serve for information purposes, e.g. for vehicle operator interfaces or manufacturer
specifications.
© ISO/SAE International 2024 – All rights reserved
v
International Standard ISO/SAE 12906:2024(en)
Road vehicles — Test procedures for electric vehicles to
determine charging performance
1 Scope
This document specifies test procedures to determine the charging performance of electric vehicles. This
document facilitates clear and consistent comparisons of realistic charging capabilities of electrically
propelled vehicles (EVs) via commercially available electric vehicle supply equipment. It provides details
about test conditions, test methods and test processes derived from typical use cases. Furthermore, it
specifies requirements regarding the information for the vehicle operator.
This document is applicable to EVs, including plug-in hybrid EVs.
This document does not provide requirements for mopeds and motorcycles.
Unless specified otherwise, all test procedures can be applied to AC, DC or wireless charging methods.
NOTE Specifications for reverse power transfer are under consideration.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1
applicable driving test
ADT
driving test provision including test procedure and requirements for homologation in the intended market
EXAMPLE Worldwide harmonized light vehicles test procedure; SAE J1634.
3.2
ADT schedule
collection of one or more driving cycle(s)
EXAMPLE Worldwide light-duty test cycle; urban dynamometer driving schedule.
3.3
DC electric energy consumption
EC
DC
R
EC,DC
energy withdrawn per unit of distance from the RESS (3.9) for operating the EV (3.5) as measured by the
combined test procedure defined in the ADT (3.1)
Note 1 to entry: Charging losses due to AC charging are excluded.

© ISO/SAE International 2024 – All rights reserved
Note 2 to entry: The unit of the distance referred to depends on the specification in the ADT.
Note 3 to entry: In the worldwide light-duty test cycle, the consumption of the combined test procedure is called
EC .
DC,WLTC
3.4
discharged battery energy
DBE
E
DBE
energy removed from the RESS (3.9) during the ADT schedule (3.2)
Note 1 to entry: At the end of the ADT schedule the DBE equals the usable battery energy.
3.5
electrically propelled vehicle
EV
vehicle with one or more electric drive(s) for vehicle propulsion
[SOURCE: ISO 6469-3:2021, 3.15 — The abbreviated term “EV” has been added.]
3.6
EV supply equipment
EVSE
equipment or combination of equipment that provides dedicated functions to supply electric energy from
a fixed electrical installation or supply network to an electrically propelled vehicle (3.5) for the purpose of
charging
[SOURCE: IEC 61851-1:2017, 3.1.1, modified – Examples were deleted.]
3.7
indicated state of charge
indicated SOC
residual capacity of rechargeable energy storage system (3.9) available to be discharged as indicated to the
vehicle operator
Note 1 to entry: Indicated state of charge is normally expressed as a percentage of full charge.
[SOURCE: ISO/TR 11954:2024, 3.11, modified — The term was originally RESS state of charge and “as
indicated to the vehicle operator” has been added.]
3.8
optimizing features
all vehicle functions that positively impact the test results when activated either automatically or by the
vehicle operator
EXAMPLE Battery thermal preconditioning functions activated by navigation systems, specific charging modes
selected by the vehicle operator.
3.9
rechargeable energy storage system
RESS
rechargeable system that stores energy for delivery of electric energy for the electric drive
EXAMPLE Battery, capacitor.
[SOURCE: ISO 6469-1:2019, 3.22, modified — “Flywheel” has been deleted from the examples.]
3.10
recharged usable battery energy
rUBE
E
rUBE
calculated share of UBE (3.13) that is recharged within a certain period

© ISO/SAE International 2024 – All rights reserved
3.11
remaining electric range
range calculated based on the battery capacity remaining for driving and the EC (3.3) of the EV (3.5) as
DC
determined in the ADT (3.1)
3.12
soaking
establishing a targeted steady state by exposing the EV (3.5) to defined environmental conditions
3.13
usable battery energy
UBE
usable RESS (3.9) energy determined according to ADT (3.1)
Note 1 to entry: See Figure 1.
Key
1 energy entering the RESS (see MP3 in Figure 4)
2 Q for recharging (e.g. loss due to cell chemistry, heating in RESS)
loss
3 Q for discharging (e.g. loss due to cell chemistry, heating in RESS)
loss
4 UBE/rUBE (see MP4 in Figure 4)
100 RESS
Figure 1 — Relationship between energies and losses at the RESS
4 Abbreviated terms
AC alternating current
DC direct current
GPS global positioning system
PER pure electric range
RMS root mean square
WLTC worldwide light-duty test cycle
WLTP worldwide harmonized light vehicles test procedure
5 General
The test procedures specified in this document serve to determine the charging performance of an EV.
NOTE It is not necessary to perform all test procedures.

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This document does not address bundling or the classification of vehicle configurations. It therefore does not
specify for which changes in vehicle configurations the test procedures shall be repeated. The manufacturer
may apply test results to other vehicle configurations than the vehicle configuration tested. In this case, the
vehicle manufacturer shall ensure that the values stated in the vehicle operator information (see Clause 7)
are also possible with the corresponding vehicle configurations.
The vehicle manufacturer may specify values in the vehicle operator information that are worse than the
test results achieved, e.g. to add some margin.
The vehicle manufacturer may specify a range of values in the vehicle operator information for bundling or
the classification of vehicle configurations.
NOTE The vehicle operator can be, e.g. the owner or driver of the vehicle or a test engineer.
6 Test cases and general requirements
6.1 Overview of test cases
Table 1 gives an overview of the test cases to determine the charging performance. Implementation details
on how to perform the corresponding test procedures are given in 6.3.
Table 1 — Overview of test cases
Charging
Test case Start condition End condition Test result
power
d
Normal Charge charging start and end conditions apply according — charging duration
power applied to the ADT
a — charging efficiency
in ADT
— max. charging power
start conditions 60 min — recharged electric range
apply according to obtained within 60 min of
the ADT Normal Charge
Fast Charge charging 15 km to 60 km 10 min — recharged electric range
power up remaining electric obtained within 10 min of
b
to the max. range Fast Charge
charging
c
10 % indicated SOC 80 % indicated SOC — charging duration
power sup-
ported by the
— charging efficiency
EV
— max. charging power
a
E.g. Europe 11 kW (16 A at 230 V 3-phase), US 9,6 kW (40 A at 240 V), China 7 kW (32 A at 220 V), Japan 6 kW (30 A at 200 V).
b
See 6.3.2.5 for specifications related to the starting condition.
c
See 6.2.4 for determination of indicated SOC.
d
Typically AC unless unavailable on the EV.
The Fast Charge test case is only applicable to EVs that support a maximum charging power > 22 kW.
Annex A specifies the test procedure to determine the charging performance at low ambient temperatures.
Annex B provides a test procedure for heavy duty vehicles.
6.2 General requirements
6.2.1 Vehicle manufacturer specifications
The vehicle manufacturer shall specify the required current and voltage ranges to be covered by the EVSE
for each test procedure.
© ISO/SAE International 2024 – All rights reserved
For AC charging, the vehicle manufacturer shall additionally specify the number of phases and the charging
cable applied.
The vehicle manufacturer specifications should take region-specific availabilities (e.g. supply network
connections) into account.
The EVSE applied in the testing shall support the specifications of the vehicle manufacturer to allow the
maximum charging performance of the EV under test.
If applicable, the vehicle manufacturer shall explain how to activate optimizing features (e.g. specific
charging modes, GPS navigation, activation via diagnostic function).
6.2.2 EV run-in
The EV under test shall have been run-in according to the specifications of the ADT. If the ADT does not
specify run-in requirements, the EV shall have been run-in at least 300 km or one full charge distance,
whichever is longer.
NOTE The EV run-in time can differ between battery electric vehicles and externally chargeable electric hybrid
vehicles in the ADTs.
6.2.3 Measurement tolerances and accuracies
The vehicle manufacturer shall take measurement tolerances and accuracies into account in the
determination of the test result. External measuring tools and/or on-board measurement data from the EV
may be used in the tests.
Table 2 provides sample rate, accuracy and resolution for different parameters that shall be applied in the
measurements described in this document.
Table 2 — Measurement sample rates, accuracies and resolutions
Measured parameter Sample rate Accuracy Resolution
Time [s] - ±1 s ≤ 1 s
Indicated SOC [%] 1 Hz as provided by the EV ≤ 1 %
Energy [kWh] during dis- 20 Hz for the voltage and ±1 % of reading, or ≤ 1 Wh
charge to measure the DBE current measurements
0,3 % of full scale of meas-
(see 6.2.5)
urement device,
whichever is greater
Energy [kWh] to identify the Watt-hour meter, Class 1 in accordance with IEC 62053-21 or equivalent
charging efficiency (see 6.2.6)
Electrical power [kW] (see 1 Hz ±1 % of reading ≤ 10 W when charging
6.2.7) power < 10 kW and
≤ 100 W when charging
power ≥ 10 kW
The full scale of the measurement device should not exceed the maximum measured parameter to the extent
that it significantly impacts the test result.
NOTE A wideband meter (power analyser) or wideband ampere-hour meter for pulsed power electronics can be
used for the DBE measurement.
6.2.4 Determination of indicated SOC
The indicated SOC shall be obtained from the on-board measurement data of the EV or from the on-board
indication.
NOTE The indicated SOC at any other interface available can be used for plausibility checks but can be subject to
certain latencies.
© ISO/SAE International 2024 – All rights reserved
6.2.5 Determination of recharged electric range by recharged energy
In ADTs, the vehicle’s EC is usually determined using a measurement at the RESS terminal.
DC
During Fast Charge, a large share of energy is typically transferred to heat just inside the RESS because of
heat generated by electric resistances at high charging current (Figure 1, key 2).
Therefore, the measurement of the electric energy added to the RESS (Figure 1, key 1) is higher than the
energy stored in the RESS.
Consequently, the measurement of the electric energy added to the RESS (Figure 1, key 1) is not suitable
to determine the effectively delivered rUBE inside the RESS (Figure 1, key 4). The method specified in the
clause solves this problem and determines the rUBE in good approximation.
a) Determination of rUBE
1) Required measurements during ADT schedule
During the ADT schedule the DBE of all RESSs and the indicated SOC shall be synchronously recorded.
The measurements shall allow the association of the DBE to an indicated SOC interval.
Care shall be taken to calculate the net energy for the appropriate SOC interval including both, RESS
discharge during vehicle operation and RESS charging during regenerative braking events during ADT
schedule.
2) Required measurements during charging phase
During the charging phase, the indicated SOC and the time shall be synchronously recorded.
The time measurement shall start with the first change of the indicated SOC (=SOC_start).
NOTE The first change of the indicated SOC (=SOC_start) can be positive or negative, e.g. due to functions
before the beginning of the actual charging process.
The indicated SOC (=SOC_end) shall be recorded after t . In addition, the time t from the start
ref SOC_end
of the time measurement until the indicated SOC changes to SOC_end shall be recorded. Charging shall
continue until the SOC_end changes to the next indicated SOC (=SOC_end+1) and the time t shall
SOC_end+1
be recorded until the indicated SOC changes to SOC_end+1.
3) Calculation of rUBE within the reference time t
ref
Using the data from 1) and 2), the rUBE within t shall be calculated by subtracting the DBE associated
ref
to the SOC_end (=E ) from the DBE associated to the SOC_start (E ), taking the last
DBE,SOC_end DBE,SOC_start
uncompleted SOC_end proportionally (linearly interpolated) into account as per Formula (1):
tt−
refSOC_end
Et()=−EE + ×−EE (1)
()
rUBE refDBE,SOC_start DBE,SOC_end DBE,SOC_endDBE,SOC_end+1
t −t
SOC_eend+1 SOC_end
where
E is the recharged usable battery energy (rUBE) within the specified time span of t ;
rUBE ref
t is the reference time for recharged electric range calculation (e.g. 10 min);
ref
E
is the DBE associated with the SOC_start;
DBE,SOC_start
E
is the DBE associated with the SOC_end;
DBE,SOC_end
E
is the DBE associated with the SOC_end+1;
DBE,SOC_end+1
t is the measured time until the indicated SOC changes to SOC_end;
SOC_end
t is the measured time until the indicated SOC changes to SOC_end+1.
SOC_end+1
© ISO/SAE International 2024 – All rights reserved
Figure 2 and Figure 3 illustrate the determination of the rUBE with example values for the parameters of
Formula (1).
a d
E =72,362
DBE,SOC_start SOCe_,nd+=1271
b e
E =57,819
DBE,SOC_end SOCe_,nd=26 4
c f
E =56,138
DBE,SOC_end+1 SOCs_,tart=68
Figure 2 — Determination of DBE during ADT schedule (example)
Key
d
Y remaining electric range [km] beginning of time and SOC measurement
e
1 rUBE after 10 min
SOCs_,tart=68
f
2 rUBE measuring duration (10 min)
t
SOC_ends=94min 8
a g
t
SOCe_,nd+=1271 ref =10min
b h
t
SOCe_,nd=26 4 SOC_end+1s=10min21
c
beginning of charging
Figure 3 — Determination of rUBE during charging (example)

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With the example values from Figure 2 and Figure 3, Formula (1) leads to the following result:
10mins−94min 8
E ()10mink=−72,,362 Wh 57 819kWh+ ×−()57,,819kWhk56 138 Wh =15,154kWh
rUBE
10minm21s−9 inn48s
SOC_start, SOC_end, and SOC_end+1 shall be selected from the recorded data during the charging phase. If
any of these values do not align with the indicated SOC values recorded during the ADT schedule, a linear
interpolation using the next lowest indicated SOC and the next highest indicated SOC recorded during the
ADT schedule shall be used to identify the E , E , or E values as necessary.
DBE,SOC_start DBE,SOC_end DBE,SOC_end+1
EXAMPLE 1 During discharge, the measurement indicates the DBE of 57,589 kWh when the vehicle reports an SOC
step to 26,8 %, and the DBE of 58,125 kWh when the vehicle reports an SOC step to 26,1 %. However, during charging,
the final SOC step recorded from the vehicle before the end of test, SOC_end, is 26,4 %. This recorded SOC value was
not provided by the vehicle during discharge but was provided during charge. The E between 26,1 % and
DBE,SOC_end
26,8 % is identified by linear interpolation: E = (58,125 kWh − 57,589 kWh) / (26,8 % − 26,1 %) × (26,4 % −
DBE,SOC_end
26,1 %) + 57,589 = 57,819 kWh.
b) Determination of recharged electric range
The recharged electric range during a charging phase shall be calculated from the EC according to
DC
Formula (2). The result of the calculation of the recharged electric range shall be rounded down to integer
numbers.
Et()
rUBE ref
rt()= (2)
rPER ref
R
EC,DC
where
r (t ) is the recharged pure electric range within the specified time span of t ;
rPER ref ref
E (t ) is the recharged usable battery energy (rUBE) within the specified time span of t ;
rUBE ref ref
R is the DC electric energy consumption (EC );
EC,DC DC
t is the reference time for recharged electric range calculation (e.g. 10 min).
ref
EXAMPLE 2 The rUBE within the time period of 10 min is 15,154 kWh. The vehicle’s EC is 0,15 kWh/km. The
DC
result for the recharged electric range within 10 min of charging is (15,154 kWh / 0,15 kWh/km) = 101 km.
6.2.6 Determination of charging efficiency
Charging efficiency shall be calculated as the relationship between rUBE and the energy provided to the
EV according to Formula (3). The rUBE shall be determined according to 6.2.5, where t is the measured
ref
charging duration from the Normal Charge test procedure respectively from the Fast Charge test procedure.

© ISO/SAE International 2024 – All rights reserved
E
rUBE
η =×100 (3)
charge
E
MP
where
η is the charging efficiency of the charging phase;
charge
E is the recharged usable battery energy (rUBE) determined according to 6.2.5;
rUBE
E is the provided energy at the corresponding measurement point.
MP
The relationship shall be expressed in percentage, rounded to one decimal place.
NOTE 1 The charging duration for Normal Charge is measured according to 6.3.1.2 or 6.3.1.3. The charging duration
for Fast Charge is measured according to 6.3.2.5 (10 % to 80 % indicated SOC).
For AC charging, the provided energy (E ) shall be measured at MP1 (see Figure 4) or at MP2 (see Figure 4)
MP
for the same period of time as the measurement of the rUBE.
For DC charging, the provided energy (E ) shall be measured at MP2 (see Figure 4) for the same period of
MP
time as the measurement of the rUBE.
For wireless charging, this subclause does not apply.
NOTE 2 Product standards for wireless charging systems (e.g. ISO 5474-4 and SAE J2954) have a specific procedure
for determining the charging efficiency.
Key
1 supply network (mains)
2 EVSE
3 EV
4 RESS
MP1 voltage and current between utility and EVSE (typ. AC; 50 Hz or 60 Hz)
MP2 voltage and current between EVSE and vehicle (AC or DC)
MP3 voltage and current into cells of the RESS (DC)
MP4 calculation of rUBE
Figure 4 — Visual description of measurement points (MP) used in the document
6.2.7 Determination of maximum charging power
To determine the maximum charging power supported by the EV, the power provided to the EV shall be
recorded during the charging duration.
For AC charging, the provided power shall be measured at MP1 or at MP2 (see Figure 4).
For DC charging, the provided power shall be measured at MP2 (see Figure 4).

© ISO/SAE International 2024 – All rights reserved
For wireless charging, this subclause does not apply.
NOTE Product standards for wireless charging systems (e.g. ISO 5474-4 and SAE J2954) have a specific procedure
for determining the charging power.
The maximum charging power is the highest averaged power within a 30 s interval during the charging
duration.
For AC charging, the maximum charging power shall be expressed in kW, rounded to one decimal place in
the case of maximum charging power < 10 kW, or rounded to an integer in the case of maximum charging
power ≥ 10 kW.
For DC charging, the maximum charging power shall be expressed in kW, rounded to integer numbers.
6.3 Test procedures
6.3.1 Test procedure for test case Normal Charge
6.3.1.1 General
To assess multiple vehicle properties, an EV must execute the ADT. As part of the ADT, any EV under test
executes a charging phase until full charge to assess the recharged electric energy E . If the ADT does not
AC
specify such a charging phase, the charging phase shall be executed according to WLTP.
To determine the performance of Normal Charge, the charging duration of this charging phase until full
charge shall be measured during the execution of the ADT.
6.3.1.2 Normal Charge AC
The charging duration shall be measured from the point in time the charging current exceeds 1 A (RMS) at
any phase until the end-of-charge criterion is reached according to the ADT.
...