Info on BMW hybrid battery packs?

[Ev8]

check out the first page of my project thread https://openinverter.org/forum/viewtopic.php?t=1414
for the pack that are on their sides i dissembled the connectors from the bmw hv interlink cables ground the Ultsonicly welded cable off leaving a connector i could then solder solid copper bus bars to

[Pete9008]

Hi, I've just got hold of one of these packs (12kWh, 6 module pack out of a 2020 330E) and was hoping to read the cell voltages out through the connector on the outside of the pack before opening it up and invalidating any warranty. Is this possible?

I had assumed that SimpBMS could read the data from the pack external connector but having reread this entire thread, and all the other threads I can find, I'm starting to think that it needs to be connected directly to the internal CAN bus within the pack and not the external one. Can anyone confirm this?

I've powered up the pack via pin 1 & 3 (+12V) and pin 12 (Gnd) and it pulls around 200mA for around 10sec before dropping back to 0mA. During this time it will ACK CAN frames, so I'm happy it's connected correctly, but I haven't been able to get it to reply to anything.

Thanks in advance.

[tom91]

SimpBMS works with the modules directly and not the full pack with the master.

[Pete9008]

Many thanks for the confirmation, I'll pull the top off the pack tomorrow and connect directly to the modules.

Is there is anything that can be done via the external connector?

[Pete9008]

Just successfully measured the data from my pack using the internal CAN bus.

All the cells within each module are within a few mV of each other, the average over the module for 5 of the modules are within 1mV of each other. The final module's average is around 5mV higher than the others:

Code: Select all

Module:1, Voltages:3.834,3.833,3.834,3.833,3.833,3.834,3.833,3.832,3.833,3.834,3.833,3.833,3.833,3.834,3.833,3.833, Temperatures:22.0,21.0,21.0, Balance State:0
Module:2, Voltages:3.827,3.828,3.829,3.828,3.827,3.829,3.829,3.829,3.828,3.828,3.827,3.829,3.827,3.829,3.826,3.828, Temperatures:22.0,22.0,22.0, Balance State:0
Module:3, Voltages:3.828,3.827,3.827,3.827,3.828,3.829,3.829,3.829,3.827,3.828,3.827,3.828,3.829,3.828,3.829,3.827, Temperatures:22.0,21.0,22.0, Balance State:0
Module:4, Voltages:3.828,3.827,3.829,3.829,3.827,3.829,3.828,3.829,3.828,3.828,3.828,3.827,3.829,3.828,3.828,3.828, Temperatures:21.0,22.0,21.0, Balance State:0
Module:5, Voltages:3.826,3.828,3.827,3.826,3.828,3.827,3.828,3.828,3.826,3.827,3.826,3.828,3.827,3.828,3.826,3.826, Temperatures:21.0,22.0,21.0, Balance State:0
Module:6, Voltages:3.827,3.827,3.828,3.828,3.828,3.828,3.829,3.829,3.828,3.829,3.829,3.828,3.828,3.828,3.829,3.828, Temperatures:21.0,22.0,21.0, Balance State:0

No idea of the history of the pack (how often it was plugged in to charge or how long it's been standing) other than it's 2 years old. These numbers look reasonable to me but would appreciate opinions?

Also wanted to say thanks to everyone who has contributed to making it possible to do this. It's really great to be able to get such a good indication of pack condition so quickly.

[jokeitch]

Not sure if it's in here but, has anyone identified what the C rating on these batteries are? I'd be doing four parallel strings of 6 most likely, and want to put them being a model s performance rear drive unit, and I'm wondering if the batteries could handle that

[cloudy]

The same modules were used in the i8 which claimed an output of 98kw on the original gen cells (The newer Gen4 ones may have a better rating) . I'd guess you could safely count on 400kw with 4P - probably a fair bit more.

[remy_martian]

To clarify: the **electric motor** of the i8 had the 98kW rating.

The battery was 7.1kWh moving to 11.6kWh for 2018-2020

https://en.m.wikipedia.org/wiki/BMW_i8

[Pete9008]

Has anyone had any success in getting the S-Box in these to close its contactors? It would be really nice to retain is as is rather than replacing the electronics.

Alternatively does anyone have a Canbus log from a working car taken while the contactors are closing?

Thanks.

[OutlandishPanda]

I don't think so. The S-Box has been decoded for CAN message coming out for current, pack voltage and DC bus voltage successfully as noted further up in this topic. I and others hard wired the contactors to an open BMS like SimpBMS so you know exactly what is happening with them. Note also mentioned is that the 2012-2018 contactors are at their very limit in the original application. The latest S-BOX has updated contactors - from 2018 I think in the G20. There is info on that in these pages.

[Pete9008]

I don't think so. The S-Box has been decoded for CAN message coming out for current, pack voltage and DC bus voltage successfully as noted further up in this topic. I and others hard wired the contactors to an open BMS like SimpBMS so you know exactly what is happening with them. Note also mentioned is that the 2012-2018 contactors are at their very limit in the original application. The latest S-BOX has updated contactors - from 2018 I think in the G20. There is info on that in these pages.

Thanks for that. I had seen the earlier posts (and am planning to use the current and voltage outputs) but was hoping that something might have changed on the contactor drive side.

Mine is the later battery and so hopefully has the updated contactors (haven't opened up the S-Box to check yet).

[tom91]

The SBOX spits out CAN messages that give you current and voltage for the pack and DC bus.

Attached is a DBC file for SavvyCAN that can de-code it.

I've connected the modules and the S-BOX together on a CAN bus, connected to SimpBMS. They can co-exist, but there is a shared use of message ID0x200 unfortunately, which is the S-BOX current - how unlikely was that! Anyway, the 0x200 from the CSCs, as far as I've noticed always, has 0 for bytes 5 6 7 whereas the S-BOX message never seems to have that, so they can be separated.

Quick note i have come across, in the Gen 2 packs, 0x200 has on byte 6 a 0x06 instead of 0x00 so best to just look at byte 5 and 7 being empty instead of all three.

Anyone manage to do any reverse engineering of the Isolation measurement circuit and controls?

[OutlandishPanda]

Interesting. Someone in this topic has managed to engage the small relay on the board in the BMS which is related to that either a self test or connection to the bus. So possibly hopeful but I’ve not had the time to work on that. Would be great to get that working. ISO Bender units for this are ~€500?

As an aside, I’ve just had UK high voltage competent person training where I learnt UK automotive regulations expect a separate service isolation switch in the HV circuit inside the pack and that relying on contractors alone (BMW) is not sufficient for the system to be considered able to be made safe. I was planning on using a BMW 5 module pack unmodified as it fits perfectly in my Panda with no additional disconnect. Seems that may not pass an inspection if ever requested by DVLA (I’m only expecting an MOT where I doubt they will spot it - it will have an HVIL service disconnect switch). Anyone any views or experience on that? Makes sense as there are plenty of examples of welded contactors in these valuable posts.

[Pete9008]

Is it possible that BMW treat the cable connection on the outside of the pack as a service isolation point?

It's positioned to be easily accessible and is relatively easy to connect/disconnect. It also looks like it should be able to cope with a fair number of operations.

[andybpowell]

Does anyone know if these modules can be mounted upside down safely ?

[arturk]

Does anyone know if these modules can be mounted upside down safely ?

I have done it about two years ago on my Jag. I don't think they were meant to be installed like that but so far I have not had any issues with that.

[Jurgen1910]

Great work all you guys here on the Bmw Phev modules . I would like to integrate the Phev s-box in my ess setup , manually controlling the contactors with the simpbms but can the current sensor in the s-box be used by the simpbms ? What additional coding / hardware needs to be done ? I read that outlandish panda has it running . Or is it just a setting of current sensor in the current firmware ?
Thanks and keep up the good work

[cloudy]

Anyone happen to have one of the CSC's spare they would sell (and ideally a connector) - want to monitor a 16S battery...

[arturk]

Anyone happen to have one of the CSC's spare they would sell (and ideally a connector) - want to monitor a 16S battery...

I have one, you can PM me

[cloudy]

All sorted - does anyone happen to have a pinout for the 16S cell taps/temp sensors?

[OutlandishPanda]

Yes, I have made that for the second generation CSCs; the ones with one white plastic master and five black plastic slave CSCs. I've not checked to see if the first gen (all the same black CSCs I believe) have the same pin out. Which one do you have?

I made a mock up of a module using 32 AAA batteries to safely mess about with a modified master CSC in testing a non-CAN comms solution directly to the BMS BQ76PL455 chip on these CSCs, so removing the BMS CAN interface limitations. Based on the excellent work mjc-506 has shared here: https://github.com/mjc-506/bmsSerial.

This works really well and you can get root access to everything including choose what individual cell to balance (any number of cells across the whole pack) and have as many or as little modules in series as you wish up to the limit. With the Master / Slave CSCs and the original master CSC BMW CAN interface, it was not happy with less that six modules connected and I believe you cannot enable balancing if not using a complete pack.

If you just want cell voltage and temp, not bothered with balancing, the master works OK on its own over CAN using SimpBMS. I don't know, but possibly the first gen will also work and provide temp and voltage data.

I'll dig out the pin info and share it when I find it...

By the way, I came across the Volvo XC90 T8 module controller (CSC equivalent) PCB today with the same BMS chip (PL455) for 16 cells. And it is tiny so if you are short of space and can be bothered with the PL455 comms mods to talk to it, that might be an option. Same as this:
https://www.diyelectriccar.com/threads/ ... 827/page-2

[cloudy]

Using a first gen (all black modules, no master) - when Tom and I we were working on balancing originally, I seem to remember one module alone would still balance. Obviously the newer gen with the white master doesn't play so nicely.

If you are able to dig up the taps that would be great! The temp ones are fairly obvious, but I'm just trying to get the logic powered up, which I assume takes from the full pack voltage neg/pos taps.

[espriev]

Does anyone have a list of the interconnect cables by part number (cell module connectors in BMW parlance) that shows the length of the cables?

Thanks!

[bobby_come_lately]

Hi,
Can you let me know how you connected your busbars to the Battery module + and - ?
Sam

Assume you're using the supplied connectors from the pack for the inter-module connections? For connecting the whole pack up, I've done it two ways:
1: Cut up the connections from the pack to the external connector and added crimp terminals, then used brass bars with an M6 thread in them going through a (thick) 3d-printed sheath in the skin of the battery box. This was OK but makes connecting/disconnecting hard (it needs a spanner). I probably wouldn't do it again unless I could find a way to make that easier.
2: Second time around I have my junction box mounted permanently to the battery pack and I have the backplane from the S-box inside the junction box. Now I can use the original connectors to connect from the battery modules to the backplane, and then take off power from there using the threaded connections. It's not pretty but it's cheap and makes connection/disconnection easy.

[Zieg]

Does anyone know what info was in those newtis links Damien posted on page 1? They are all dead now.

Would also really like to know what kind of power people are getting from these and how they are cooling them. Thinking about grabbing a 12kwh pack for my Locost build.