VW Golf VIII hybrid, Cupra Formentor hybrid Battery

[arber333]

I managed to purchase a Cupra Formentor Hybrid 1.5L battery P/N 5WA915589L.
Battery is also found in VW Golf VIII Hybrid and Seat Leon Hybrid all from 2024 onwards.
For now i only have a teaser, but later on i will perform another battery porn for you all .
Also i have SIMP BMS here that would allow me to test if the BMS would respond to known commands...

[tom91]

It be very intresting to see inside as this is a very nice dense pack for 26kWh at 171kg.

[arber333]

It be very intresting to see inside as this is a very nice dense pack for 26kWh at 171kg.

I am actually hoping to replace the battery of our Ampera completely with this.
I assume a lot here, but if this battery is liquid cooled and i can connect to the cell contacts that shouldnt be hard...

[arber333]

I am actually hoping to replace the battery of our Ampera completely with this.
I assume a lot here, but if this battery is liquid cooled and i can connect to the cell contacts that shouldnt be hard...

Battery scheduled for delivery tomorrow

[skr]

Should we send you a chisel? :p

[arber333]

Should we send you a chisel? :p

For some reason battery spent a weekend in storage. I just got it delivered yesterday...
I do need a chisel... VW makes me infuriated by their strange fasteners obsession....

I mean... how do you untorque that? I spend an hour dealing with those screws and then i simply used angle grinder where i could and where i couldnt i manually (chisel) turned those screws until i could turn them by hand...

[arber333]

Finally Cupra hybrid battery arrived!
It was about 200kg withoutt pallet weight. Looked undamaged at first glance.

Some data points for those that will be interested in geting one

With it i got external LV cable so we can determine its PN...

First i undid the top screws which were just the normal torx.

Before i removed the top cover in full i measured full voltage and on orange terminals i didnt get any, those are after contactors. I did however measure 338V on the inner contact points where contactor assembly connects to the bus. I determined positive bus...

Contactor assembly is weird with 4x 150A contactors welded in pairs and wired for control circuit to turn on in conjunction with precharge resistor. I have not yet figured out how it works... At the back contactors are connected to 12V power, and everything is welded!!!

Contactors are controlled by master circuit which is under top cover

BMS module is from two boards in a single plastic casing. Here we are in luck as this module gathers all cell values at a single location, process them and it looks like it outputs CAN...

BMS cables look the same as from ID3 BMS side connectors.

While cell level connectors are smaller. I intend to make a cell level pinout of both sides later today...

This sums up first part of dissassembly since the page wont allow me to upload more pics. I will open next post for continuation...

[arber333]

Like i showed cell top is covered by a thick white plastic.

At the front this is framed by orange DC rails which is about 30mm2 of copper and close to 60mm2 of braided copper wire on flexible points.

Cell connections are made by unique round joint with M6 torxs screw in the middle.

This is easily unbolted, however i am not sure how much power can those puny contacts carry...

Cell modules are retained by 4x M8 strange torx bolts per module. I had to get a special tool from a friend because i dont have this one and my ordinary torx would skip if i applied too much torque...

Modules are 4x 24S1P configuration energy 6,54kWh and about 50kg each. I will weigh them later using a luggage scale when i prepare myself

I tested them for voltage and all were exactly at 84,6Vdc

Then there are 18pin cell level connections. As before with VW ID3 cells i can measure thermistors from connector edges with cell voltages in the middle

Modules are arranged by 4 bolted in alu box with pressed sheet metal liquid cooling under the box.
Modules are under 60cm in length 22,5cm in width and under 11cm in height.

Some more photos of cell modules

Alu casing is only on the module edges and makes for cell protection and retention. Under and over that is soft plastic covering. On the underside i can feel cell block mass. This is pressing to the heat transfer foil that is located underneath battery tray.

I will dissassemble and show more of the liquid cooling tomorrow when i sort oout where to put the modules. In the mean time the mounts and steel braces really help with module retention as the box itself is really just a thin tray. What is giving it strength and stiffness is a large 8mm alu plate in the bottom where coolant outlets connect to.

[arber333]

As soon as i saw that BMS is not built in the cell modules but rather connected via cables i got realy interested.
This means i can connect various BMS modules to it directly via its cables.

Even better cell values are distributed in 12S connectors which makes my job even easier. I intend to use this battery for our Opel Ampera battery replacement. I need to use OEM BMS so the car wont be the wiser...

Again photo of BMS and cable connections

Some cell cable PNs

I see PN for requisition of parts 3WA971689AB for the first cell cable, then 3WA971689R for two modules in the middle and 3WA971689S for the last module. 3WA971689P is the BMS power and comms cable.

And there is a simple power and CAN cable to supply BMS with 12V and communication

Brown wire seems like 12V and green as GND with orange/brown and orange/blue as CAN twisted pair

I opened up BMS cover and i see chips for 12S sections

Tomorrow i will try to connect 5V to BMS connector and test if i get anything out of CAN lines...
Then low power 12V....

Things i do for you

[skr]

These seem to follow vda590 standard - same as other MEB modules.
My guess by the prismatics is that they are Catl (most likely) or SK made.

Given that they are 1P it would be interesting to figure out what the current capability is, very likely not far off from 12s2p catl meb modules divided by two.

https://www.evcreate.com/using-volkswag ... y-modules/

The special torx bolt is XYZ 12point, used everywhere in VWs.

Be careful with fusible links/fuses. Athough these can be accessed easily below plastic lids, you are most likely limited at 750mA balancing unless you tap directly.

I visited that flex factory in Hungary some years ago where the BMS was made, they were very secretive about manufacturing iqos e cigs next to LTE base stations and everything else one can imagine

Btw check if reverse engineered vw id bmu doesnt talk the same language as yours

[arber333]

...
Given that they are 1P it would be interesting to figure out what the current capability is, very likely not far off from 12s2p catl meb modules divided by two.
.....

I see cells are 73Ah, and if they are CATL this should mean 73A x 3 = 219A rated for intermittent action. Modules are sort of liquid cooled even though i consider Volt/Ampera cooling much more efficient that simple under plate VW offers. I will probably make my own cooling plate as well as mounting options.

[arber333]

Some more details of cell modules uncovered
Module weighs about 30kg

I managed to peel off the plastic cover from the top to see cell level connections...

Under the plastic cover there is also 1mm thick foil which is functionaning as isolator.
Also i was a bit dissapointed as the positive most contact is transfered from the other side of the module and it is rather thin per my standards.

Connectors on the module are 18pin JST connectors.

I cant find any usefull P/N to order a replacement besides OEM VW. I only know they are two keys that fit in a specific order.

Later i will make a schematic for the cell tap connections in a table form

[Ruudi S]

Interesting, thanks for detailed overview.
What are complete battery case measurements?

[arber333]

Interesting, thanks for detailed overview.
What are complete battery case measurements?

I hadnt had time for my workshop lately... was busy with the parking lot ...
I will post some more info later...

[arber333]

OK now... where were we...

So i read the pinout on the 24S module. Its straightforward thermistor followed by the negative most contact for supply and then by sensing contacts.
I put the table from my notes to PDF.

VW 24S battery module.pdf

(203.92 KiB) Downloaded 4 times

Connecting to those should be light work.

Now however i took the BMS module apart to see what is inside.

It is assembled from two boards. There are 8 sensing modules on each board. Each module is connected to its neighbour via some sort of two wire interface.

Boards are separated by plastic mount

I still cant see what kind of chips are there. They are covered by protection goo that i cant see trough. If someone has any idea on how to get plastic protection off to read the chips please... I tried to scrub some of it using a scalpel and i only managed to remove the markings partially.

Top board is fully used for battery sensing and it uses opto couplers to communicate with other modules.
On the bottom board there is a logic unit with two large chips that receive voltage from outsde and a CAN module or some sort.
I recognised two 60R resistors termination.

Here is the VW marking on the board

I connected to the board via its native connector. I surmised green wire is the positive supply and brown is the negative assuming power is protected from reverse polarity by a diode on the photo. With 5V supply circuit pulled 6mA power and if i increased this to 12V it would draw 10mA.
I tried to connect to CAN lines with my CAN reader at 500kbps and 250kbps and 125kbps and i didnt get any live comms out of it.

Does anyone know what MEB BMS comms request for BMS is? I want to try it while i still have all cell cables in one piece. I am planning to unwrap them and make new Ampera BMS harness from them...

[tom91]

They usually are powered from the HV side and require modules connected to work.

Or atleast thats how the ID3/4 MEB slaves work.

[arber333]

They usually are powered from the HV side and require modules connected to work.

Or atleast thats how the ID3/4 MEB slaves work.

Yes i did connect cells to BMS from the orange cables. That was easy. But when i connected 5V and 12V to the other side of the circuit barrier i got 0.1A consumption and nothing else. No CAN report or anything. I tried to listen with my eCAN USB transciever.

Can you show me link to where there is VW BMS CAN request so i can try if i have to wake up the BMS perhaps?

[tom91]

Ah yes check my github: https://github.com/Tom-evnut/VW-bms/blo ... WBMSV2.ino

Code: Select all

int controlid = 0x0BA;

void sendcommand() {
  msg.id = controlid;
  msg.len = 8;
  msg.buf[0] = 0x00;
  msg.buf[1] = 0x00;
  msg.buf[2] = 0x00;
  msg.buf[3] = 0x00;
  msg.buf[4] = 0x00;
  msg.buf[5] = 0x00;
  msg.buf[6] = 0x00;
  msg.buf[7] = 0x00;
  Can0.write(msg);
  delay(1);
  msg.id = controlid;
  msg.len = 8;
  msg.buf[0] = 0x45;
  msg.buf[1] = 0x01;
  msg.buf[2] = 0x28;
  msg.buf[3] = 0x00;
  msg.buf[4] = 0x00;
  msg.buf[5] = 0x00;
  msg.buf[6] = 0x00;
  msg.buf[7] = 0x30;
  Can0.write(msg);
}