Outlander VCU - Rear inverter, Charger and BMS

[tom91]

Now, just need to figure out what is the deal with the phantom 11th module when the DCDC is plugged in to the CAN bus

It is down to the DCDC broadcasting messages that are inside the range of the module messages. I believe AOT runs multiple canbuses and does not combine everything on one bus.

[bigdaveakers]

It is down to the DCDC broadcasting messages that are inside the range of the module messages. I believe AOT runs multiple canbuses and does not combine everything on one bus.

Hmmmm, the BMS board only has one CAN bus and from his schematics the bus also connects to the charger. I seem to recall reading something about it somewhere but I thought this build worked.

Perhaps it is simply a case of ignoring CMU6 (which seems to be where the DCDC message wants to insert itself).

Pretty sure he has a solution though

[aot93]

Yes the charger / DC DC should sit on the same bus as the BMS.
I'm not at a pc right not so cant check it.
I do exclude the DCdc id in the code so it should be ok.
I'll look in to and get back

[bigdaveakers]

II uploaded the hex file to the Teensy, maybe should have compiled from the source in Github

Will give that a whirl in the morning

[bigdaveakers]

Compiled the Github code, uploaded it to the Teensy, problem fixed!

Now All I need to do is get the ATTiny programmed, any help?

As I understand this uses the Proximity Pilot signal and pulls in the changeover relay to power the boards from the battery rather than ignition supply and activates IN3(AC ON) in to the BMS which puts the bmsstatus to Charge (as long as the settings for contactor cotrol are Direct to Battery as the VCU handles the contactors?)

[aot93]

Ah yes you will need to use the code from the GitHub page.

It's good to be able to build from source as you will be able to modify anything you need to.

The plug detect code is here:

https://github.com/aot93/Plug_Detect it's built for vscode, but you can just change the .cpp to .ino and it should build in arduino.

There good guides around for setting up and programming the ATtiny, i found it easier to use and host board like this
https://www.ebay.co.uk/itm/313603433626 ... R_zro5m7YQ

Your understanding of the operation is correct.

Good luck!

[bigdaveakers]

I have been able to get the BMS and VCU in charging state

Have ordered a charging cable to plug in to our existing wall box so hopefully soon I will be able to get some current flowing in to the batteries!

Any tips on the Outlander cell settings in SimpBMS would be appreciated. I like fireworks but not inside the garage!

[bigdaveakers]

My cable has arrived, but I dont appear to be getting any charging current

When I plug the cable in the prox pilot does its thing and puts the BMS in to charge status (3) and the VCU in to charging status (6).The dash green light is flashing and the contactors are pulling in but I dont see any AC volts in the VCS debugger

image.png (2.56 KiB) Viewed 137817 times

and the Charger Status stays at 20

Looking through the BMS debug log every so often the DC Enable relay toggles in and out (or out and in) and I get an indefeasibly large CANbus Current Sensor voltage (100s of Amps) for 1 cycle. However, the first time this happens the SOC jumps from 51% to 100% and stays there until a power cycle.

I suspect that I dont quite have the settings right for the Outlander battery.

[bigdaveakers]

Well.......it turns out that when it is below freezing in the garage you need to change the low temperature derate from 0 to something below the cell temps

I changed it to -3 and would you believe that the cells started to charge! I dont have any coolant at the moment so shut off when the charger temp hit 30 (mainly because I could no longer feel my fingers).

However, I am still getting the toggling of the DCDC relay and associated current spikes, I mentioned 100s of amps, but it turned out to be a few more. Can you spot the odd one out? I am pretty sure that I am NOT putting 2 million amps through the charger but that may explain why it is so keen to report 100% SOC after the event. I guess I need to change the SOC calculation from coulomb counting to voltage based

4.165
4.158
4.145
4.16
4.154
2019908.992
8.33
4.15
4.148
4.147
4.17
4.154

The problem seems to be that my charging current is 0.25A which is below the threshold for turning off the DCDC relay (0.5V) but then the battery drops to below 12V which immediately turns it back on again. 30 seconds later the process repeats. Each time there is a spike on the current sensor. The perils of using a knackered old 12v battery!

[aot93]

That current spike is not something I have seen, are those values from the charger or from the BMS current sensor?
are you using a CAN bus current sensor (LEM CAB300/500) ?


If your 12V battery is shot then it could be worth just hard wiring the DC-DC enable to keep it on.

[bigdaveakers]

That current spike is not something I have seen, are those values from the charger or from the BMS current sensor?
are you using a CAN bus current sensor (LEM CAB300/500) ?


If your 12V battery is shot then it could be worth just hard wiring the DC-DC enable to keep it on.

That is from the BMS Current Sensor, the one from inside the Outlander pack. It is reported in the debug log of the BMS. It only happens for a short time and is as a result of the DC Enable relay turning off and straight back on.

[bigdaveakers]

OK, I have a question........

In the code the message 377 is decoded

Code: Select all

void canRX_377(const CAN_message_t &msg)
{
  charger12vbattryVolts = float(((msg.buf[0] * 256) + msg.buf[1]) * 0.01);
  charger12vCurrent = float(((msg.buf[2] * 256) + msg.buf[3]) * 0.01);
  chargerTemp1 = msg.buf[4] - 40;
  chargerTemp2 = msg.buf[5] - 40;
  chargerTemp3 = msg.buf[6] - 40;
  chargerStatus = msg.buf[7];
  avgChargerTemp = (chargerTemp1 + chargerTemp2 + chargerTemp3 + chargerTemp4) / 4;
}

but in the wiki 377 is defined as

Is there a scaling issue? It seems sensible to me as the charging current is only showing as 0.5A with a dead dead battery......

[EV_Builder]

What does your current clamp say?
If it says 5 it's an copy paste error.
If it says 0.5 the wiki is wrong.

[traikerS]

Hello. I want to start charging without everything else. Where can I see the file only for charging up to 400v

[arber333]

Hello. I want to start charging without everything else. Where can I see the file only for charging up to 400v

You can make a clean file yourself based on the info in this thread.
viewtopic.php?p=8079#p8079

Also be advised outlander charger is just a current pump and it doesnt limit voltage. Here is info how i used its own can report to read voltage and stop the charging.
viewtopic.php?p=49079#p49079

[EV_Builder]

Also be advised outlander charger is just a current pump and it doesnt limit voltage. Here is info how i used its own can report to read voltage and stop the charging.
viewtopic.php?p=49079#p49079

Are you sure? There is one voltage setpoint at Startup and then current setpoint remains.

[arber333]

Are you sure? There is one voltage setpoint at Startup and then current setpoint remains.

Nope, charger doesnt care.I gave it the limit of 360Vdc and it just pushed the current past the limit up to 400Vdc where it expired. I had the 420Vdc battery at the time so no problem, but big whoooa!

So i went on to use its own voltage report to close a feedback loop. It works, but it is only accurate by 2V since the feedback is single byte. Still better than no limit if your ISA shunt goes sideways.

[Bigpie]

Someone has reported that it only takes notice of the voltage set point once (on wiki) and the 12v needs to be removed to reset.
I've not tested that, I just have my BMS taper the current as the highest cell gets closer to the voltage setpoint

[bigdaveakers]

Someone has reported that it only takes notice of the voltage set point once (on wiki) and the 12v needs to be removed to reset.
I've not tested that, I just have my BMS taper the current as the highest cell gets closer to the voltage setpoint

I have been trying to charge my pack for the first time. It was all going well until I hit around 3.91V per cell (75% SoC) and then the charge current dropped dramatically and I am now not seeing an increase in cell voltages. Need to poke around in the code to see what the limitation is this time.....first it was too damn cold in the garage for the charge to start due to the 0 degrees C limit in SimpBMS

[celeron55]

Someone has reported that it only takes notice of the voltage set point once (on wiki) and the 12v needs to be removed to reset.
I've not tested that, I just have my BMS taper the current as the highest cell gets closer to the voltage setpoint

It was me who wrote that, but since then I've begun doubting the result of that test I made. Should probably add a big bunch of question marks in there as nobody else seems to have confirmed it.

[arber333]

It was me who wrote that, but since then I've begun doubting the result of that test I made. Should probably add a big bunch of question marks in there as nobody else seems to have confirmed it.

I can confirm that sometimes charger can get stuck and that can be resolved by turning 12V off and then reconnecting. Also this happens when disconnecting HV and reconnecting. Charger goes into error state untill you reset 12V.
DCDC will also fail to supply aux voltage in that case.

[EV_Builder]

I have been trying to charge my pack for the first time. It was all going well until I hit around 3.91V per cell (75% SoC) and then the charge current dropped dramatically and I am now not seeing an increase in cell voltages. Need to poke around in the code to see what the limitation is this time.....first it was too damn cold in the garage for the charge to start due to the 0 degrees C limit in SimpBMS

This is typical Voltage setpoint a bit too low. Current can only flow if voltage is risen. But don't go above cell limits.

[bigdaveakers]

This is typical Voltage setpoint a bit too low. Current can only flow if voltage is risen. But don't go above cell limits.

Setpoint is at 4100mV so I assumed that it would head for this. If this is not the case I will have a play and increase it slightly.....

[EV_Builder]

Yeah maybe it's not that accurate..maybe check the resistance of connections... Voltage measurements can differ quite a bit.

[bigdaveakers]

So I see that the charge hysteresis actually defines the where the battery will charge to.

Setpoint of 4100mV minus the hysteresis of 0.2V gets me to 3900mV.

What was more alarming is that when I plugged in today it wouldn't even pull the contactors in because it was above 3900mV (slightly) I bumped up the setpoint to 4200mV and it started drawing current.

I thought I had killed something

Thanks all for your patience guiding me through this. Soon I am going to have to start considering getting it off the bench and in the car.