Info on BMW hybrid battery packs?

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Re: Info on BMW hybrid battery packs?

Post by bobby_come_lately »

Has anyone installed these modules on their side rather than flat? Is there a good reason not to do so?
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Re: Info on BMW hybrid battery packs?

Post by chrskly »

I guess since they're cooled out the bottom plate you might want to have their bottoms touching the outside wall of the battery box. Not that they get very hot by all accounts (not firsthand knowledge).
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Re: Info on BMW hybrid battery packs?

Post by bobby_come_lately »

chrskly wrote: Fri Aug 06, 2021 2:53 pm I guess since they're cooled out the bottom plate you might want to have their bottoms touching the outside wall of the battery box. Not that they get very hot by all accounts (not firsthand knowledge).
This was my thinking. But the temps really don't seem to change much, at least on charging. I've only charged at 8A so far but the temperatures didn't move more than a degree.

If I can rotate the modules 90 degrees I can fit five side by side between my chassis rails, saving a load of space in the engine bay and lowering the weight down in the car. Might give it a try.
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Re: Info on BMW hybrid battery packs?

Post by Jack Bauer »

I covered the temperature issues on the BMW hybrid packs of the conversion courses. Here is a short version : ask yourself what is different about how we (bev) builders use the packs versus how bmw (phev) use them...
I'm going to need a hacksaw
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Re: Info on BMW hybrid battery packs?

Post by chrskly »

Jack Bauer wrote: Mon Aug 09, 2021 9:39 am I covered the temperature issues on the BMW hybrid packs of the conversion courses. Here is a short version : ask yourself what is different about how we (bev) builders use the packs versus how bmw (phev) use them...
Of course, I remember the wiggly graph.

Ignore me, this is an irrelevant suggestion.
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Re: Info on BMW hybrid battery packs?

Post by Ev8 »

My front pack they are mounted on the side, and they front pack is normally 3 degrees cooler than the rear pack in the boot
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Re: Info on BMW hybrid battery packs?

Post by Ev8 »

Out of interest what are people charging to?
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Re: Info on BMW hybrid battery packs?

Post by bobby_come_lately »

Ev8 wrote: Tue Aug 24, 2021 3:41 pm My front pack they are mounted on the side, and they front pack is normally 3 degrees cooler than the rear pack in the boot
Fantastic - thank you. This is going to massively improve my layout.
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Re: Info on BMW hybrid battery packs?

Post by Ev8 »

I might be getting away with it though due to spreading the load cross the 3 paralleled packs! But I’ve just driven to work, ambient temp is 17, front pack temp 17 rear pack temps 19 inverter temp 19
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Re: Info on BMW hybrid battery packs?

Post by bobby_come_lately »

I wasn't getting above 21 when charging - albeit not fast charging - so that seems pretty inline with what I'm getting.
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Re: Info on BMW hybrid battery packs?

Post by Ev8 »

I got the rear battery pack up to 38 charging with 3.3kw obc but that is inside the boot with the air cooled charger inside a black car when it was about 28 degrees outside, will have to look while charging at night
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Re: Info on BMW hybrid battery packs?

Post by celeron55 »

Living in Finland, the first thing I really want to know about batteries is in what temperature they can be charged. I'm planning to use these without active heating, so I needed to find some source of information.

Well, the closest I could get was a datasheet for some Samsung SDI 94 cells, which I guess are used by BMW in the i3. I think these PHEV cells are the same series, but with less energy density and more power density. I'm going to assume these can take about half the charge current of those 94Ah cells:
sdi 94 operating current limit vs temperature.png
I think these are pretty good batteries for cold climates, as they can always be charged, albeit with lowered current. No need to waste energy heating them just to charge them.

Even so, if you have just a measly 3.3kW charger, you don't need to even think about current limits before -25°C, which is really nice. You do need to be aware of this for regen though, pretty much right at 0°C.

Here's where I found the datasheet: https://shop.gwl.eu/Samsung-SDI94-NCM/L ... g-NCM.html
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Re: Info on BMW hybrid battery packs?

Post by bobby_come_lately »

That's really good to know, thanks. Doesn't get so cold here (Northern England), just very wet. Nonetheless reassuring.
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Re: Info on BMW hybrid battery packs?

Post by opelmanta »

Does these battery packs specifically 330e has current sensor and simpbms can read it?
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Re: Info on BMW hybrid battery packs?

Post by OutlandishPanda »

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.

There is a picture in an earlier post from me on page 8 in this thread on how to connect 12V and get to the CAN bus. Note, the Can H and Can L may be swapped in that picture - I can't remember now.

Tom should answer if SimpBMS can now read SBOX messages. The version I'm modifying does not.

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.

FYI, this is how I've modified SimpBMS to use the S-BOX current:

Code: Select all

void canread()
{
  Can0.read(inMsg);
  // Read data: len = data length, buf = data byte(s)

  //update this for S-BOX
  /*
  if (inMsg.id == 0x3C2)
  {
    CAB300();
  }
  */

  // Updated for S-BOX CAN messages (assumes S-BOX is OK sharing with the module CAN bus 0)
  //ID = 200 Current
  if (inMsg.id == 0x200)
  {
    SBOXcurrent();
    //Serial.println("S-Box Current Received!!!!! &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&");
  }
  //ID = 210 Pack Voltage
  if (inMsg.id == 0x210)
  {
    SBOXbatVoltage();
    //Serial.println("S-Box Bat Voltage Received!!!!! &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&");
  }
  //ID = 220 DC Bus Voltage
  if (inMsg.id == 0x220)
  {
    SBOXdcBusVoltage();
    //Serial.println("S-Box DC Bus Voltage Received!!!!! &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&");
  }
  ...
Then to decode the CAN message:

Code: Select all

// ID 0x200 Pack Current +-mA
void SBOXcurrent()
{
  // make sure to reject the ID0x200 message sent from the CSCs, which always has 000 for bytes 5,6,7
  // we only want to process ID0x200 measages from the S-Box
  // Unlucky both use ID0x200 but luckily very easy to separate:
  if (!((inMsg.buf[7] == 0) && (inMsg.buf[6] == 0) && (inMsg.buf[5] == 0)))
  {
    //must be from S-BOX current so process:
    inbox = inMsg.buf[2];
    inbox = (inbox << 8) + inMsg.buf[1];
    inbox = (inbox << 8) + inMsg.buf[0];

    if ((inMsg.buf[3] & 1) == 1)
    {
      CANmilliamps = inbox - 0xFFFFFF - 1;
      // may need to get rid of -5mA offset I see at zero current
    }
    else
    {
      CANmilliamps = inbox;
    }

    //Serial.println("$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$");
    //Serial.print("S-BOX Current: ");
    //Serial.println(CANmilliamps);
    //Serial.println("$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$");
    //Serial.print("mA inbox = ");
    //Serial.println(inbox);

    if (settings.cursens == Canbus)
    {
      RawCur = CANmilliamps;
      getcurrent();
    }
    
    if (candebug == 1)
    {
      Serial.println();
      Serial.print(CANmilliamps);
      Serial.print("mA ");
    }
  }
}
This is untested other than it compiles, runs and displays the current from the SBOX sensor when it should correctly, but not tested in a working vehicle. If anyone is interested, pack and DC volts can also be de-coded and used if desired. I'll use this for pre-charge and contactor management.

If you do test this for real, please report your findings! I'm getting closer but still not at connecting the HV stages yet!

Thanks again to Tom for sharing the SimpBMS code.
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Re: Info on BMW hybrid battery packs?

Post by bobby_come_lately »

Ev8 wrote: Tue Aug 24, 2021 3:42 pm Out of interest what are people charging to?
Realised no-one answered this and I have the same question. I'm charging to 4100 at the moment but wondered about going higher.
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Re: Info on BMW hybrid battery packs?

Post by Ev8 »

I have charged to 4150 with no noticed I’ll effects but as the car is of the road until the new motor and inverter setup in finished I can’t test further
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Re: Info on BMW hybrid battery packs?

Post by bobby_come_lately »

Ev8 wrote: Sat Oct 16, 2021 7:55 am I have charged to 4150 with no noticed I’ll effects but as the car is of the road until the new motor and inverter setup in finished I can’t test further
Going back to the original limits of the pack as suggested earlier in the thread, I'm thinking about sticking between 3000 and 4000

Pack voltage | Cell voltage | SoC (notional)
332 4.15 100%
321.2 4.015 90%
310.4 3.88 80%
288.8 3.61 60%
267.2 3.34 40%
245.6 3.07 20%
234.8 2.935 10%
224 2.8 0%
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Re: Info on BMW hybrid battery packs?

Post by Ev8 »

You can certainly try, but my experience was they start falling rapidly at 3.3v so in practice I was only discharging to 3.4v
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Re: Info on BMW hybrid battery packs?

Post by bobby_come_lately »

Ah OK. That might explain my accidental extreme range test. Thought my pack might have been a bit degraded but maybe it's just that.

Doesn't give a huge amount of range.
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Re: Info on BMW hybrid battery packs?

Post by Ev8 »

Maybe it’s a degradation thing also, my 3 packs paralleled are all either 2016 or 2017 modules and the cell dela at rest after balancing is 3-6mv thought that 4.1- 3.4v range then grows quickly to worrying numbers, guess that’s top balancing for you
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Re: Info on BMW hybrid battery packs?

Post by cloudy »

Has anyone noted the model/rating of the HV fuse in the newer sbox? (with the orange contactors) Thanks!
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Re: Info on BMW hybrid battery packs?

Post by Linukas »

Ev8 wrote: Tue Aug 24, 2021 3:42 pm Out of interest what are people charging to?
I checked my bmw hybrid with diagnostic tool and I see that charging ends at 4.15v.
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Re: Info on BMW hybrid battery packs?

Post by Ev8 »

Excellent info thanks
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Re: Info on BMW hybrid battery packs?

Post by Turbopete »

OutlandishPanda wrote: Thu Jul 09, 2020 7:54 am Got to my pack, connected a MCP2562 transceiver to a Teensy 3.2, loaded SimpBMS BMW PHEV as per Tom's posts above (latest version) and connected as below. Success!! I can see all the modules and cells and its a healthy pack. Couldn't test balancing as my pack seems well balanced (2mV delta), which was a surprise given it has sat untouched for many months. I assume it can't balance disconnected from the vehicle?

A few pics of my setup and links if that is any help to anyone below.

Transceiver (I used 2562 and connected VIO to 3.3V):
http://ww1.microchip.com/downloads/en/D ... 05167C.pdf

Tom's code:
https://github.com/tomdebree/BMWPhevBMS

I disconnected the BMW BMS and connected in to the blue connector: PHEV CAN2b.jpg

You can see from this picture of my breadboard I had to terminate the CAN lines at the transceiver with 120R.PHEV CAN3.jpg

The 3 first modules power and CAN is separate from the last 2, so needs two sets of 5V connections.
The CAN lines for the 3 and 2 module sets also "seem" to be separate, measuring the continuity of the CAN lines to the modules and this connector, but only one of the CAN lines for the first three modules needed to be connected to be able to see them all on that CAN bus. No idea how/why, but seems to work fine and means termination is easier. Perhaps I measured it wrong.

The 5V line takes about 64mA when enabling all 5 modules, so probably also powering some of the logic of those boards.PHEV CAN1.jpg

The output I recorded was:

Code: Select all

BMS Status : 1 Ready     80

Out:0000 Cont:0000 In:0000 Charge Current Limit : 10 A DisCharge Current Limit : 30 A

Modules: 5 Cells: 80 Strings: 1  Voltage: 289.420V   Avg Cell Voltage: 3.618V  Low Cell Voltage: 3.617V   High Cell Voltage: 3.619V Delta Voltage: 2mV   Avg Temp: 19.600C 

Module #1   57.89V   Cell0: 3.62V   Cell1: 3.62V   Cell2: 3.62V   Cell3: 3.62V   Cell4: 3.62V   Cell5: 3.62V   Cell6: 3.62V   Cell7: 3.62V   Cell8: 3.62V   Cell9: 3.62V  Cell10: 3.62V  Cell11: 3.62V  Cell12: 3.62V  Cell13: 3.62V  Cell14: 3.62V  Cell15: 3.62V

 Temp 1: 21.00C Temp 2: 20.00C Status: 0x0 Bal: 0x0

Module #2   57.88V  Cell16: 3.62V  Cell17: 3.62V  Cell18: 3.62V  Cell19: 3.62V  Cell20: 3.62V  Cell21: 3.62V  Cell22: 3.62V  Cell23: 3.62V  Cell24: 3.62V  Cell25: 3.62V  Cell26: 3.62V  Cell27: 3.62V  Cell28: 3.62V  Cell29: 3.62V  Cell30: 3.62V  Cell31: 3.62V

 Temp 1: 19.00C Temp 2: 21.00C Status: 0x0 Bal: 0x0

Module #3   57.88V  Cell32: 3.62V  Cell33: 3.62V  Cell34: 3.62V  Cell35: 3.62V  Cell36: 3.62V  Cell37: 3.62V  Cell38: 3.62V  Cell39: 3.62V  Cell40: 3.62V  Cell41: 3.62V  Cell42: 3.62V  Cell43: 3.62V  Cell44: 3.62V  Cell45: 3.62V  Cell46: 3.62V  Cell47: 3.62V

 Temp 1: 20.00C Temp 2: 19.00C Status: 0x0 Bal: 0x0

Module #4   57.89V  Cell48: 3.62V  Cell49: 3.62V  Cell50: 3.62V  Cell51: 3.62V  Cell52: 3.62V  Cell53: 3.62V  Cell54: 3.62V  Cell55: 3.62V  Cell56: 3.62V  Cell57: 3.62V  Cell58: 3.62V  Cell59: 3.62V  Cell60: 3.62V  Cell61: 3.62V  Cell62: 3.62V  Cell63: 3.62V

 Temp 1: 18.00C Temp 2: 19.00C Status: 0x0 Bal: 0x0

Module #5   57.88V  Cell64: 3.62V  Cell65: 3.62V  Cell66: 3.62V  Cell67: 3.62V  Cell68: 3.62V  Cell69: 3.62V  Cell70: 3.62V  Cell71: 3.62V  Cell72: 3.62V  Cell73: 3.62V  Cell74: 3.62V  Cell75: 3.62V  Cell76: 3.62V  Cell77: 3.62V  Cell78: 3.62V  Cell79: 3.62V

 Temp 1: 20.00C Temp 2: 19.00C Status: 0x0 Bal: 0x0

CANbus   0.00mA  51% SOC 13260.00mAh
Very happy with that. The voltages all moved around a tiny bit over time, so they were "live". Now working on a very simple display to connect in to the Teensy to help with debugging on the bench and sorting out the contractors etc. and adding a simple mode change button.

Also, need to incorporate the important charge and discharge limits vs. duration these little packs have, as alluded to here: https://batteryhookup.com/products/bmw- ... 1288381572

That certainly looks like our module but not identical? You can see the 10 sec max power limitation in discharge and charge (re-gen braking). No idea where they would have got this info or how reliable it is but helpful nonetheless. (That was a fantastic price!!) Note the voltages also. I think the lowest voltage is too low?

So, from what I've found on the web, the 330e pack, I think, will do somewhere between 23kW and 32kW continuous power (with cooling), and 58kW to 65kW peak for 10 sec (With lots of cooling!) Some references state 70kW peak, and BMW state the 330e has a 65kW motor, which would match a 70kW battery peak, but that seems quite extreme!

The usable capacity is consistently stated as 5.7kWh. We can work out the usable SOC range and so voltage range from that.

These are all with a very capable, active refrigerant system. Unless that is re-instated, I'm not sure we can access those peak power ratings very often! Also, I'd wonder if the BMW BMS would be modeling the thermal behaviour of the cells vs current in and out and be running a kind of feed forward control to the cooling system. Activating cooling from the sensor measurements may be too slow I'd guess? For a huge EV pack I don't think this is such a big deal but operating these small PHEV packs at peak power for more than a few seconds is going to need care I think?

If anyone has any experience using these packs, has found a good cooling solution and has more reliable data, please share!

I'm thinking of investigating what of the 330e refrigerant system can be re-used with an eAC compressor and my Panda's (eventual) AC system. My first idea of putting water in the pack's refrigerant lines is probably not going to do much, but worth also investigating?

Quick question to Tom, I notice when I remove power to the modules, the CAN comms stop, but none of the data displayed changes from then, its frozen, obviously. I've not had a chance to test yes, but what is your thinking around the status of the BMS when/if that happens? Does it indicate it has lost comms with the modules and suggest zero charge and discharge capability or some other mode change to warn of an unprotected pack? I could see no change in behaviour when I powered down the modules. Maybe I'm worrying too much for a home build!

Thanks.
Apologies if the answer to this question is obvious - I’m learning as I go! - the 5v line appears to be taking its voltage from the teensy vin pin - I thought this was 3.3v max when powered by usb? Have a missed something obvious or is 3.3v actually enough for the 5v line?
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