Bug found - Samsung BMS

[chuotde]

My setup:

• Inverter: Solis S5-EH1P5K-L
• Battery: 2x Samsung ELPM482-00005 in parallel
• RPi with 2-CAN HAT, can0: BMS, can1: inverter
• BMS-to-Inverter configuration: can0: SAMSUNG_CAN; can1: PYLON_CAN

Issue: Discharge current limit sent to inverter is wrong, inverter sees it as 645.9A

can0 dump: can0 502 [8] 45 02 AC 03 AC 03 C0 01 --> charge and discharge limit are the same 0x3AC
can1 dump: can1 351 [8] 45 02 AC 03 54 FC C0 01 --> discharge limit is 0xFC54 (64596)

Bug found in: SamsungBmsCANProcessor.java, line 151

pack.maxPackDischargeCurrent = data.getChar() * -1; --> should not times the value by -1, (0x3AC + 0xFC54 = 0x10000)

Can you please fix it? Many thanks.

[chuotde]

Maybe another bug with cells voltage display on webUI: only 12 cells are available out of 28 cells

https://i.ibb.co/0vxgPm3/Screenshot-20250201-092110.png

I propose a change like this:

            case 0x5F0:
                readCellVoltages(pack, data, 0);
            break;
            case 0x5F1:
                readCellVoltages(pack, data, 3);
            break;
            case 0x5F2:
                readCellVoltages(pack, data, 6);
            break;
            case 0x5F3:
                readCellVoltages(pack, data, 9);
            break;
            case 0x5F4:
                readCellVoltages(pack, data, 12);
            break;


            protected void readCellVoltages(final BatteryPack pack, final ByteBuffer data, final int cellNoStart) {
                    // Tray id
                    final int tray = data.getShort() - 1;
                    // Cell voltage (1mV)
                    pack.cellVmV[cellNoStart + tray * 14] = data.getChar();
                    // Cell voltage (1mV)
                    pack.cellVmV[cellNoStart + tray * 14 + 1] = data.getChar();
                    if (cellNoStart != 12) {
                        // Cell voltage (1mV)
                        pack.cellVmV[cellNoStart + tray * 14 + 2] = data.getChar();
                    }
                }

[ai-republic]

Hi @chuotde, thanks for the bug spotting :)
I've added the changes. Please re-test (Clean install) with the latest changes and let me know if it works 😄

[chuotde]

Hi,

• 1st issue with wrong max discharge current: no change (I still see * -1 in your code - line 151)
• 2nd issue with cells voltage: all look good.

Thanks for your quick fix

[ai-republic]

@chuotde thanks for the feed back. I fixed the discharge also. Could you please retest and confirm?