CMU Board : notes, eprom, cell re-numbering, CAN messages

[kiev]

if we can connect i alone (= without the LEV50N cells) and power it to carry out tests?

See post #5 for power supply and post #7 for CAN buss schematics.

There are 2 power supplies for the CMU. Replace the cells with a power supply at the A+ and D- board terminals for the first, and then supply 12V at pin4 with -return at pin 6 to enable and supply the second.

Without cells attached what sort of testing would you, or could you, do?

 

[piev]

They are not located under the white blob, just near it (can be seen in the picture).

i measured 3 of them on one of my boards, all reading 7.19k Ohms at 70 F, and dropping to 6.5k when heated with my finger. Physical size is 0402 inch or (1005 metric).

Based upon this i think the part number is:
TH05-3N682F for a 1% device.

Here is a datasheet for Mits chip thermistors, NTC type.
digikey datasheet

Thanks Kiev you are a blessing to the forum

 

[avilinks]

I would like to add an additional pack to my residential battery. As I use BMS cards, I would like to have a CMU numbered 11.

To renumber a CMU, is the simplest method to rewrite the first byte of the eeprom with an arduino for example?

 

[kiev]

Maybe Piev can share some CAN Buss findings of a single CMU board?

 

[piev]

Maybe Piev can share some CAN Buss findings of a single CMU board?

Hooked up to a Module and took a data dump

Time Stamp

ID

Extended

Dir

Bus

LEN

D1

D2

D3

D4

D5

D6

D7

D8

Column1

Module

Temp

Temp

Temp

Voltage

Voltage

160758029​

651​

FALSE​

Rx

0​

8​

5​

00

40

40

01

83

01

83

5​

57.2​

57.2​

3.795​

3.795​

160758347​

652​

FALSE​

Rx

0​

8​

5​

3F

3F

00

01

82

01

82

5​

55.4​

55.4​

3.79​

3.79​

160758658​

653​

FALSE​

Rx

0​

8​

5​

3F

3F

00

01

83

01

83

5​

55.4​

55.4​

3.795​

3.795​

160758979​

654​

FALSE​

Rx

0​

8​

5​

00

00

00

01

83

01

83

5​

3.795​

3.795​

 

[MickeyS70]

Temperatures are transmitted with an offset of 50 and in deg Celsius, i.e. 40 hex -> 64 dec -> 14 deg C -> 57.2F

There are a few different formulas for decoding the voltages online, the one I found most accurate is (MSB * 256 + LSB) / 200 + 2.1V

@piev that would make your example 4.04V, did you measure the cells with a voltmeter?

 

[piev]

Not home now but pretty sure those are the formulas I used.

Double checked and according to excel my numbers are correct.
=((HEX2DEC(H3)-50)*9/5)+32
=2.1+((256*K2+L2)/200)

Unless you can see an error

Never mind I see it. forgot to convert to decimal first.
=2.1+(256*HEX2DEC(K2)+HEX2DEC(L2))/200