DIY Electric Car Forums banner
1 - 15 of 15 Posts

·
Registered
Joined
·
21 Posts
Discussion Starter · #1 ·
Hello all,

So i have recently connected an Elcon/TC 3.3kw charger to ZEVA's electrical vehicle management system V3 and seem to be having communication issues.
Charger is:

The documentation which came with the charger denotes the following pinouts. CANL - A and CANH - B CANGND - C
The Zeva documentation says 'To connect a TC Charger to a ZEVA CANbus, join only the CANGND, CANL and CANH pins.' Which has been done.

The TC Charger, on power up, appears on the Zeva Monitor with the settings i have selected.It will say 'Charger OK' but within seconds 'Comms Timeout' appears.

If i connect the Charge Sense wire, to ground, on the Zeva management unit (which is required to turn on the charger), the buzzer starts to sound and the following warning flashes 'BMS - Comms error'.

The Charger does turn on briefly, but then shortly stops.

If anyone has any insight in to how i can solve this issue, it would be much appreciated.
Thank you
 

·
Registered
Joined
·
21 Posts
Discussion Starter · #2 ·
So i have contacted ZEVA as well who has said if i change the BMS12 modules cell count to Zero, the charger should start correctly.
Which it has.
This is due to 'The BMS Comms Error when you enter charging mode is usually due to a mismatch between the EVMS’s settings and the physical BMS modules connected to its CAN bus.'

I am still waiting to hear about what this mismatch will be though.
 

·
Registered
Joined
·
21 Posts
Discussion Starter · #4 ·
Well the mismatch was if the setting on the EVMS are different to what the BMS12 modules are connected to, unfortunately they are definitely correct so it is not that.

Bitrate issue?
what do you think? some bad data knocking everything out? or messages being sent on the wrong CAN BUS format?
 

·
Registered
Joined
·
1,498 Posts
i think you must send a CANiBUSS message to the TCCH charger every few seconds or it will timeout. Info should be in the manual or some TCCH user could chime in to give you the details.
 

·
Registered
Joined
·
913 Posts
Well obviously won't work unless Zeva is specifically designed to match the Elcon CANbus protocol specs, I assumed they at least claim to do so.

These guys are suppose to:

Emus
Orion
Elithion
EPS
 

·
Registered
Joined
·
311 Posts
I recently had issues with a TC charger being 500 kbs while all other elements of the system were 250. Was a big job to pull all modules out and re-program them, and only with Ian's help.
 

·
Registered
Joined
·
392 Posts
CAN bus has to be properly terminated. Do you have a simple schematic with terminating resistors to share with the forum?
 

·
Registered
Joined
·
21 Posts
Discussion Starter · #13 ·
Just to Clarify EVMS is EV Management System Master unit.
https://www.zeva.com.au/index.php?product=131 (PDF of the user manual is on here)

I am then using 2 slave units called BMS 12's.

So to give a brief update on everything that i tried;
Changing all the BMS 12's cell counts to Zero successfully allowed the charger to start, the charger can be controlled by the EVMS and i am able to change settings.
The minute I change either BMS 12's cell count above Zero, if i turn on the charger, i get 'BMS - Comms Error'.

Both BMS 12's are sending information to the EVMS, i am getting all cell voltages, avg volt, temp, min volt and max volt.

I am also having another error with the 'Key In' function (this is your ignition line). When i connect ignition it will cause 'BMS - Comms Error' to appear.
If the BMS 12's cell count is reduced to zero, this changed to 'Precharge Failed' (I have a EVMS with LV precharger). At this point, by disabling the precharge function it actually allowed the unit to change to RUN mode.
Again if i increase the BMS 12's cell count above zero, it goes back to 'BMS - Comms Error'

I have an Arduino connected to the CAN system which is reading temperatures from all the cells and outputting it to the EVMS. I have tried the whole system with it removed from the network but no change (it is a CAN termination point usually, so a resistor was added when it was removed).

I have been in contact with Ian from Zeva and he is being really helpful, but unfortunately can't think of a solution.

I am going to 100% go through all the wiring again today and if i have no luck he has said to send them back to him for testing.

If anyone has any further insights it would be very much appreciated.

Well obviously won't work unless Zeva is specifically designed to match the Elcon CANbus protocol specs, I assumed they at least claim to do so.
Yes it says the ZEVA unit works with TC/Elcon Chargers. It seems to be working correctly, i believe it is

CAN bus has to be properly terminated. Do you have a simple schematic with terminating resistors to share with the forum?
Yes the CAN bus is properly terminated. There is a termination resistor in the monitor and one in the arduino. When i removed the arduino i added a new termination resistor. I get 60 ohms when it is powered down so correct.
The CAN network currently consists of Monitor -> EVMS (Spur to charger) ->Current Sensor -> BMS12 0 -> BMS12 1 -> Arduino CAN Board
 

·
Registered
Joined
·
392 Posts
Again, a schematic would be nice. What are you using to send CAN messages to the charger? This doesn't sound like a charger problem it sounds like an EVMS problem. The Manual you posted says it's not getting messages from the BMS.
 

·
Registered
Joined
·
21 Posts
Discussion Starter · #15 ·
So i sort of fixed the issue.

I had been supplied with a modified .hex file to allow me to read the temperatures with the arduino and send it to the EVMS.
The EVMS requires 4 data packets from the BMS 12 modules otherwise it throws up the error (3 voltage 1 temp). The modified file was meant to allow the temp data packet to be sent by the arduino.
The data is being sent by the arduino, as i am getting temperature readings when looking at the monitor.

But when i rolled back the firmware on the BMS12 to its base .hex file it is no longer showing a BMS - Comms Error.
I have contacted Zeva to see if they can look at the modified .hex file they supplied, as i think that was causing the problem.

Unfortunately i have also run into another problem with the BMS reading the wrong voltages now, which is less than ideal. That is a new topic though so will create a new post.
 
1 - 15 of 15 Posts
Top