Outlander CMU Simp BMS

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RAS_666
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Outlander CMU Simp BMS

Post by RAS_666 »

I havent actually run the simp bms code yet because i neither have a full pack or something suitable to run it off however i have been messing decoding the messages from the individual cmu boards. I noticed that there appears to be 5 separate temperature readings in message 6x1 data fields 2 through 6 i work them out to be decimal value -52 altho my thermometer could be a few degrees out.
https://github.com/tomdebree/OutlanderP ... Canbus.pdf
using this formula does result in a sensible temperature reading at normal ambient temperatures however as the temperature starts to rise it is nowhere near. I see this same Formula in the simpbms Code is this correct and i have a different cmu or is it calculated differently elsewhere?
here is an example od the can output from one of my boards.

Code: Select all

CAN1,691,8,0,30,49,49,49,49,49,FF,
CAN1,692,8,E,67,E,67,E,67,E,64,
CAN1,693,8,F,31,F,36,F,21,F,2E,
CAN1,694,8,FF,FF,FF,FF,FF,FF,FF,FF,
This translates to:
++++++++++++++++++++++++++
hextodec-52 21C 21C 21C 21C 21C
Simp BMS 18C 18C 18C
3891mv 3894mv 3873mv 3886mv
3687mv 3687mv 3687mv 3684mv
30.29v ID: 694

if i wave a lighter over temp sensor #1 the one on the negative terminal:
++++++++++++++++++++++++++
hextodec-52 64C 22C 21C 21C 21C
Simp BMS 29C 18C 18C
3891mv 3894mv 3874mv 3888mv
3687mv 3687mv 3685mv 3684mv
30.29v ID: 694
PatrykS
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Re: Outlander CMU Simp BMS

Post by PatrykS »

0x49 = 73 = 50+23
When you subtract 50 from the reading you get the temperature, not sure why SimpBMS got different result (21). For LEV46 you need to subtract 70, for LEV40 50. It's not easy to cool or warm entire module, but when you get the temperature sensor off the cell bolt it is much easier. I checked at different temperatures (from -10 degrees C in the fridge up to +70 degrees in the oven) and it worked really well (+/- 1 degree). There are 5 sensors, sixth one in the CAN frame (0xFF) should be ignored.
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RAS_666
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Re: Outlander CMU Simp BMS

Post by RAS_666 »

I have the cmu and the balance wires all loose for testing they are connected to a small rc lipo. It's probably supposed to be -50 I just set it at that because it mached my thermometer.
Simp bms uses a different formula:

Code: Select all

temp[CMU][0] = rxBuf[2] * 256 + rxBuf[3];
        temp[CMU][1] = rxBuf[4] * 256 + rxBuf[5];
        temp[CMU][2] = rxBuf[6] * 256 + rxBuf[7];
Not entirely sure why :?

Trying to see if I can make it work on all 10 cell's and 12 modules next will be the challenge
PatrykS
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Re: Outlander CMU Simp BMS

Post by PatrykS »

>> Not entirely sure why :?
A saw such implementation/documentation, but it's wrong, maybe untested.

>> Trying to see if I can make it work on all 10 cell's and 12 modules next will be the challenge
Checked 10 cells (removed some copper trace on the CMU before - after blowing a fuse) and it didn't work - invalid voltage 2100mV was shown for these extra cells. 12 modules won't work on single CAN - CAN IDs conflict, CMUs have unique CAN ID within one car, but the same as in another car. I'm using 2 separate CAN buses for that.
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RAS_666
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Re: Outlander CMU Simp BMS

Post by RAS_666 »

The cmu id number can be changed I think I have managed it but I don't actually have a full pack to test my theory on just yet to see if they behave as they should with all 12 on the same bus. Waiting for a mate to get round to testing that out on his car. I don't see why an extra 2 cells wired correctly would blow anything it kinda looks like it has been designed that way. But may be a software issue I'd have to look at some of the boards from an imev they are similar in a way maybe looking at how the 4 cell vs the 8 cell cmu software works.
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chuuux
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Re: Outlander CMU Simp BMS

Post by chuuux »

Hi folks.
Does anyone have a wiring diagram for connecting the balance wires to the cells? This socket pinout?
I got some of Outlander CMU, but the balance connector and wires are missing.
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