Simp BMS

[Jackk]

Please leave the CP input disconnected for testing. What do you have connected?

If nothing is connected please tie this input to 12V.

The CP is connected to pilot out from simp charge via a 5k resistor... this pin appears to be getting voltage once charge has initiated but the voltage isn't steady... around the 3v .

OK so i pulled the CP pin all together and now getting a nice 30A from the charger!! SUCCESS IT WORKS! but what about the CP line? what is its purpose? why was it stopping the charger outputting...

Thanks!!

Ok so what's the harm in leaving the CP disconnected? I presume with the max charge current set to 30A on the charge settings means it should cut charger if it exceeds that?

[tom91]

Ok so what's the harm in leaving the CP disconnected? I presume with the max charge current set to 30A on the charge settings means it should cut charger if it exceeds that?

The current you set for the DC current limit is always respected.

The current the Charger draws to generate the DC current from the AC side is not controlled. With the CP working as it should the BMS tries to estimate the AC Current that will be drawn for a given Battery Voltage and DC Current Limit and then adjust it till it fall under the CP indicated AC Current limit.

Leaving it unconnected would cause the BMS to ignore any AC Current limits and command the DC Current directly from the settings, taking any derating into account.

[arber333]

VW code has been update to now include Audi Q7 Phev 13S batteries.

Hi Tom

I have started to play with VW Passat modules at last. I see there are 7 standard wires/pins to connect SimpBMS to slave modules. But only the first connector on the harness has 7 pins. All the rest have more (9). Can you or someone explain how are the rest of the wires related? I can trace some of the pins as 12V, GND and Enable signals, but there are two additional CAN bus wires.
1. Are those wires just pass through for the slave CAN or is this a separate line?
2. I would like to use halfh pack wires into Red and black connectors that join to common pins on the master. Not all pins are alligned... Of course i will replace master with SimpBMS. Has anyone done that allready?

EDIT: I went along the wires and i can speculate further that neighbouring pins are in fact passtrough for the 12V, GND and Enable with addition of CAN H and CAN L. Everything leads to one RED and BLACK connector that are joined together on the same pins. I will test my theory in the next days.

tnx

[Bigpie]

The the Golf GTE, it's a similar setup, the wires are doubled up. Assuming for redundancy.

[arber333]

The the Golf GTE, it's a similar setup, the wires are doubled up. Assuming for redundancy.

Thanks for the confirmation! I think pins are bridged inside BMS so that wiring could be made easier.
I will work more on making integrated contactor schematic.

[Dusty4]

Currently the software for Chevy Volt Gen1 and bmw Phev.

So Tesla, VW, Outlander, BMW I3 all have support for the IVT-S shunts

Hey Tom,

would it be possible to run the shunt on the canbus expansion for the volt software?

[tom91]

Hey Tom,

would it be possible to run the shunt on the canbus expansion for the volt software?

No, the canbus expansion is way too slow to transfer the amount of messages a shunt spits out.

[Bryson]

Hey Tom,

I wired up the IVT-S current sensor today to replace the CAB sensor and I noticed that current wasn't reflecting over the serial interface or the nextion display. I dug into the code and it looks like RawCur is not set to CANmilliamps and get current() isn't called when you're set to use the IVT-S, they're only called within the CAB300 function. Has anyone successfully used an IVT-S? I made sure that I had 60 ohms across CAN H&L and did my best to dig through the code, but I'm not seeing anything that would make it work. Tesla pack for what it's worth.

[arber333]

The Outlander charger appears to only have current control, but with SIMPBMS tapering the current as a cell reaches the setpoint, that's effectively bringing down the voltage. Do I just need to do more than just put in the can communication?
I'll test it today with a 3.7 set point and see how it behaves.

Any new code to share, or link to it?

tnx

[Bigpie]

https://github.com/jamiejones85/VW-bms/tree/master. It uses a different can library, and supports 4 can buses now on a Teensy 3.6, with 2 on SPIs.

[tom91]

Hey Tom,

I wired up the IVT-S current sensor today to replace the CAB sensor and I noticed that current wasn't reflecting over the serial interface or the nextion display. I dug into the code and it looks like RawCur is not set to CANmilliamps and get current() isn't called when you're set to use the IVT-S, they're only called within the CAB300 function. Has anyone successfully used an IVT-S? I made sure that I had 60 ohms across CAN H&L and did my best to dig through the code, but I'm not seeing anything that would make it work. Tesla pack for what it's worth.

Good Catch, I have now mended this in all version compatible with an IVT-S shunt.

[Ev8]

Just a heads up that dashupdate() in the bmwphev firmware has an additional 4th line of Serial2.write(0xff); at the end, it seems to stop the status updating on nextion display. Works fine once removed

[Ev8]

Also anyone know why the SOC resets to 100 if I go over the max current range of the cab500? It goes back to where it should be if you reset the ah counter, I suppose I could force it to reset the ah count if current goes over 500amps but seems a little hacky, I will dig into it further

[Jackk]

Hi all. Having got my TCC charger communicating with my simp and all working for some reason it now fails to turn charger on... Nothing to my knowledge has changed from when it charged perfectly last time. Tesla cells are sitting at about 4v

For some reason if I put the simp in ESS mode the charger seems to boot up...any ideas really stuck!?



Thanks

[joromy]

I see your Charge Hysteresis is set to 200mV, and charge setpoint to 4200mV.
Then charging should not start, if cells are > 4000mV.
Could that be it?
Try setting Charge Hysteresis to 100mV

[Jackk]

Joromy you ledgend that sorted it. Panic over thanks very much!!!!

Jack

[Jackk]

Now onto the next....

My nextion display is not recieving data from the simp...what steps should I take?

[FJ3422]

Have you already tried to swap the RX and TX wires to the display ?

[Jackk]

Thanks FJ342 !!! that worked a treat!

[mfuchs]

Hello everyone,

currently I try to set up SimpBMS with a Tesla battery. Everything works fine but I have troubles with the alarm settings…
Example:
Over voltage setpoint: 4100mV
Under voltage setpoint: 3200mV

When the minimal cell voltage goes under 3200mV the BMS goes into error state, but when the maximal cell voltage goes over 4100mV nothing happens. But when I do a restart in this situation, it tells an error until I change the over voltage setpoint. So it somehow does not recognize the over voltage alarm in running mode.

What can be wrong here?

Thanks and regards

[tom91]

What can be wrong here?

It should be working fine let me try and replicate.

Please share snap shots of your settings and debug.

I cannot replicate the issue at the moment.

[mfuchs]

Hi,

thanks for the reply.
Here is what I configured:

alarmSetting.PNG (12.47 KiB) Viewed 6075 times

SimpBMS keeps running:

After I do a reeboot it goes into error state (which it should):

[tom91]

What is the firmware version? Mind updating it to the latest

[mfuchs]

This is the installed version:
Firmware Version : 261020

[Jackk]

Hi guys,

how do I get switch the 5v supply to the nextion display to come on with ignition switch (pin 1 J5).

Currently nextion display is on all the time as Its powered from the permanent 12v in (pin 8 J4). Simp needs to have a permanent live so that the charger kicks in with ignition off...

Thanks!