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Battery: BMW iX, i4‐i7 (Gen5 platform)

lenvm edited this page Jan 14, 2026 · 22 revisions

Caution

Working with high voltage is dangerous. Always follow local laws and regulations regarding high voltage work. If you are unsure about the rules in your country, consult a licensed electrician for more information.

BMW Gen5 BEV Platform - (iX, i4, i5, i7)

BMW uses a shared modular platform across various vehicles with a common BMS (SME). BMW i4 for example has the SE26 or SE27 configuration.

Unlike i3, Gen5 now uses CAN-FD on the external side, and ISO-SPI between SME > Cell modules.

Technical data SE10 SE11 SE12 SE13 SE16 SE26 SE27 SE30 SE50
Vehicles iX iX iX1 iX1, iX2 iX3 i4 i4, i5 i7 iX
Number of battery cells (lithium-ion battery) 500 180 156 188 288 324 408 450
Chemistry NCA NMC NMC NMC NCA NCA NCA
Configuration 100s5p 90s2p 78s2p 94s2p 96s3p 108s3p 102s4p 90s5p
Number of cell modules 5 cell modules (8s5p)
6 cell modules (10s5p)
10 cell modules (9s2p) 8 cell modules with 18 battery cells
2 cell modules with 22 battery cells
4 dual-cell modules (two 12s3p) 3 cell modules (4s3p)
4 dual-cell modules (two 12s3p)
Nominal Voltage 368 V 330.3 V 286.3 V 345 V 354 V 398.5 V
Voltage range Min. 280 V - max. 430 V Min. 252 V - max. 378 V Min. 218.4 V - max 327.6 V Min. 263.8 V - max. 394.8 V Min. 268.8 V - max. 408 V Min. 302 V - max. 464 V Min. 285.6 V Min. 252.0 V
Battery capacity 303.0 Ah 232.0 Ah 232.0 Ah 232.0 Ah 198.6 Ah 210.6 Ah 280.8 Ah 303.0 Ah
Capacity per cell 60.6 Ah 116.0 Ah 116.0 Ah 116.0 Ah 66.2 Ah 70.2 Ah 70.2 Ah 60.6 Ah
Max. storable energy quantity 111.5 kWh 76.6 kWh 66.45 kWh 80 kWh 70.27 kWh 83.9 kWh 105.7 kWh 100.35 kWh
Max. useful energy quantity 106.3 kWh 70.6 kWh 73.8 kWh 68 kWh 80.7 kWh 101.7 kWh
Dimensions of the housing (length x width x height) 2410 mm x 1742 mm x 141 (303) mm 2410 mm x 1742 mm x 141 (303) mm 2228 mm x 1586 mm x 311 mm 2261 mm x 1708 mm x 285 mm 2261 mm x 1708 mm x 285 mm
Total weight 649 kg 521 kg 436 kg 518 kg 500.9 kg 564.5 kg
Cooling system Coolant Coolant Coolant Coolant Coolant Coolant Coolant Coolant Coolant

Software configuration

For this battery type, use the option called "BMW iX and i4-7 platform" under the "Battery Protocol" setting

image

Also remember to configure the allowed charging power, since we do not read this value via CAN.

Note on CAN-FD

The Gen5 BMW battery architecture uses CAN-FD, so if you plan on integrating this battery, you will need to get the CAN-FD chip add-on , or even easier is to just get the Stark CMR hardware

Pin Assignments at Plug Connector A332*1B

A332*1B is the external low voltage connection. Connector is a Hirschmann 805-587-545 16way 1.2 SealStar FA Connector. Some packs have the LV connection at the front of the pack and appear to use a back to back connector instead.

Pin Type Description / Signal Type Connection / Measuring Information
1 E Supply, terminal 30 Fuse F242 Power distribution box, rear
2 M Ground Ground point
3 E Terminal 30c signal High-voltage safety connector
4 E/A Wake-up signal Body Domain Controller
5 -- not used
6 -- not used
7 E/A High-voltage interlock loop signal (loop these two via 33ohm resistor) High-voltage safety connector
8 E/A High-voltage interlock loop signal (loop these two via 33ohm resistor) High-voltage safety connector
9 E Crash signal Crash safety module
10 -- not used
11 E/A CAN-FD Low
12 E/A CAN-FD High
13 E/A not used (possibly alternate pins for CAN-FD on some variants)
14 E/A not used (possibly alternate pins for CAN-FD on some variants)
15 A Activation Coolant shutoff valve 2
16 M Ground Coolant shutoff valve 2

HV Connectors

Count Connector Cable/Cap
1 DC charge connector Protective Cap Hv Battery 889520 - BMW (12-90-9-796-829)
1 or 2 main connectors Rosenberger HVS420 - Protective Cap for HV Battery 889520 - BMW (12-90-9-796-829)
1 CCU/AC Connector (100A fused) Hirschman HPS40-2 - Suitable cable is 5A2DB59-03

HV Connector Blank - 3D Printed

Here are some 3d printable covers for the large rear connector, smaller front connector and internal blanking covers for BMU (If you disconnect the additional HV outputs internally) https://www.thingiverse.com/thing:6845382/files

Pin Assignments on BMS Internal Connector

image

Pin Assignments on contactor connector (Inside BMS)

image

Example Wiring Diagram

This diagram assumes using manual contactor control (you will have to make up a 4 pin passthrough inside the battery from the SME/BMU to the spare pins on the external case). Pinout for the contactor connector is above. You can combine all 3 negative contactor connections, leaving the other 3 spare pins for the individual positives. 2WD and 4WD can vary for CANFD pinout - so check!

example wiring

CANbus Map

Expected Vehicle Messages:

ID Rate Sender Length Description / Signal Type Comments Sample
0x125 10ms CCU 20 CombinedChargerUnit10msNo2 CAD450 B1 04 7A D5 FE 7F FE 7F 0E 7E DE 9C 08 FF FF FF FF F0 FF FF
0x16E 20ms CCU 8 CombinedChargerUnit20msNo1 CAD454 85 A3 C9 FF 60 C9 22 F7
0x340 100ms CCU 12 CombinedChargerUnit100msNo1 CAD448 AB 4E 6A FF 01 31 00 00 90 87 FF FF
0x4F8 ? CCU 24 CAD454 FF FD FF FF FF 80 31 C8 00 00 F0 40 FE FF FD FF 48 5A FF FF FF FF FF FF
0x91 10ms EME 48 TractionEMachineElectronic1Time10msNo1 CAD6D8 8D A3 58 B0 36 90 43 07 0C 06 87 80 FF FF 00 80 FE E7 7F FE E7 7F FE 17 FE 57 FF FF 00 11 01 FF 00 F0 01 10 00 E0 DF FF 02 20 00 FF 00 00 00 00
0xAA 10ms EME2 TractionEMachineElectronic2Time10msNo1 CAD6E4
0x188 5000ms CCU 8 CAD4B8 FD 03 21 00 3C FF FF FF
0x1EA ? KOMBI 8 Kilometers - Odometer CAD7A5 - byte0-4LSB multiplier 0.001 E8 AC 00 00 00 FF DF 48
0x2ED ? ? 2 Ambient Temp CAD434 75 7F
0x1FC ? ? 8 Heat management control CAD720 FF FF FF FC 00 00 C0 00
0x442 ? ? 6 Relative Time CAD5F8 - byte 0-1 lsb time since starting car - seconds 59 2F A9 00 E0 23
0x21D ? ? 8 Request - HVAC CAD856 0A 03 7E FF FF FF FF C0
0x4EB ? ? 8 Status of RSU Condition CAD808 3F A1 E5 FF FF FF FF FF
0x276 ? BDC 8 Vehicle Condition CAD498 FF FF F0 FF FF FF FF FC
0x1A1 200ms DSC ? Vehicle speed HighVoltagePowerManagement200msNo1 CAD4B0
0x380 ? KOMBI? 7 VIN Last 7 Chars

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