BMS Communication On Mecer 8kW Max II and Hubble AM2 batteries

[Janosh]

I have not yet linked the BMS communication of my inverter to the batteries CAN-bus and want to do so now, because I was advised to do so by Hubble. Unfortunately, the Mecer manual is very vague regarding instructions as to how this is done, therefore my request to the forum for assistance.

I have made up the custom made RJ45 cable with the following pin selections:

Inverter:

Pin 6 = CAN-H, Pin 7 = CAN-L and Pin 8 = Gnd

Hubble battery:

Pin 2, Gnd, Pin 4 = CAN-H, and Pin 5 = CAN-L

The pin selection pins on the batteries is set Battery 1 Master, Battery 2 Slave, as per Hubble manual.

How do I connect the cable, do I need to switch the inverter and batteries off, and then connect, or is it like a "plug-and-play" with the inverter and batteries on. Do I need to change any settings on the inverter?

If someone has the correct steps to follow, I would so much appreciate your assistance.

[Psy]

OK, so you can connect the BMS while powered up but its not recommended. I would recommend turning the system off (Especially the switch on the inverter), then connect the cables and apply power to the unit. Boot the unit in "Standby Mode" and change setting 5 to the battery type advised by Hubble:

[Janosh]

Thanks so much. I will give feedback once done. Are you happy with my RJ45 pin configuration?

Edited December 2, 2022 by Janosh

[Janosh]

Ok, so I have followed the instructions above, and are not sure what indication on the inverter tells me that the BMS is actually connected, as I cannot see any new icons indicating successful connection. There is a stable "BATT" icon however.

[BritishRacingGreen]

9 minutes ago, Janosh said:

Ok, so I have followed the instructions above, and are not sure what indication on the inverter tells me that the BMS is actually connected, as I cannot see any new icons indicating successful connection. There is a stable "BATT" icon however.

You will see error/warning 61 if no comms. 

Additionally, you can try to set the menu options to set e. g . battery bulk voltage manually. If it does not allow your attempt, it is  indicative of the fact that the bms is overriding these values. 

Also if you had previously set battery values manually in USE mode, you will see them changed automatically when you establish comms. 

Also your SOC on display will be updated accordingly, although its just a small bar graph  and very coarse. 

[Coulomb]

The battery icon (just above the "75" in the crude battery SoC bar graph) should flash when the BMS connects.

2 hours ago, BritishRacingGreen said:

Also your SOC on display will be updated accordingly, although its just a small bar graph  and very coarse. 

The Max II with all that screen real estate seems to have lost the ability to display the battery SOC as a percentage, which is a bit sad. Edit: unless I'm misreading, or it's not in the manual.

Edited December 3, 2022 by Coulomb

[Janosh]

Ok, so it is not flashing. Should I set the inverter program 5 to LIB and not USE, and then the voltages etc in 26-28 as per Hubble instructions.

Also, please confirm the correct pin layouts on the RJ45 cable please:

I have it as:

Inverter:

Pin 6 = CAN-H, Pin 7 = CAN-L and Pin 8 = Gnd

Hubble battery:

Pin 2, Gnd, Pin 4 = CAN-H, and Pin 5 = CAN-L

I wish they could make the instruction more clear....

 

[Coulomb]

16 hours ago, Janosh said:

Should I set the inverter program 5 to LIB and not USE, and then the voltages etc in 26-28 as per Hubble instructions.

If you change setting 05 to LiB and have the correct cable and all is working, then there is no need to change settings 26-28, as the Hubble BMS should do that for you. Any changes you make to those settings will be ignored.

 

17 hours ago, Janosh said:

Inverter:

Pin 6 = CAN-H, Pin 7 = CAN-L and Pin 8 = Gnd

At least pins 6 and 7 are correct. Sorry, I don't have what is on pin 8 handy.

[Janosh]

6 hours ago, Coulomb said:

If you change setting 05 to LiB and have the correct cable and all is working, then there is no need to change settings 26-28, as the Hubble BMS should do that for you. Any changes you make to those settings will be ignored.

 

At least pins 6 and 7 are correct. Sorry, I don't have what is on pin 8 handy.

Thanks for your feedback Mate.

[Janusvanrhyn]

On 2022/12/03 at 6:06 PM, Janosh said:

Ok, so it is not flashing. Should I set the inverter program 5 to LIB and not USE, and then the voltages etc in 26-28 as per Hubble instructions.

Also, please confirm the correct pin layouts on the RJ45 cable please:

I have it as:

Inverter:

Pin 6 = CAN-H, Pin 7 = CAN-L and Pin 8 = Gnd

Hubble battery:

Pin 2, Gnd, Pin 4 = CAN-H, and Pin 5 = CAN-L

I wish they could make the instruction more clear....

 

Hi I’m having similar issues, i also need to make a rj45 cable. What colours do i match to your description on each pin ?

[Janosh]

Hallo Janus

I am still unable to sort out my RJ45 cable. Info about this topic seems to be very wishy washy, and I would rather not have this function, than cause damage to my batteries.

[BTTB]

From my understanding Axpert/Voltronic Inverters can't communicate directly with Hubble Batteries without the use of the Hubble Cloudlink box and then it's the cloudlink information that you are looking at, not the inverter.

Set the battery option to USE (User) on the inverter and apply the voltages recommended by Hubble here for your AM2.

I have the Axpert 11KW Inverter, the electrician setup the voltages on the inverter by checking the label on the side of the battery.
Ask your electrician for help. Stuffing up the inverter or batteries with incorrect voltages might be a costly exercise. The AM2 batteries have a built in BMS which protects the batteries from overvoltage, just be careful anyway.

At first when I had my Axpert installed I was miffed about not being able to use the CAN port to communicate with my AM2 batteries. But a month later it doesn't bother me anymore.
Every now and then I'll check the lights on the batteries and at what voltage they are charging on the inverter, after loadshedding. 

In my case the AM2 battery lights flash until the Inverter says 54.1V, then they are full and the last green light goes solid, at which point the inverter fan also stops and then voltages on the inverter fluctuate up to 56V or thereabouts for about 10 minutes and then it drops to 53.5 or 53.6 and sits there until the next loadshedding. 

Edited March 13, 2023 by BTTB
Edited voltage in last line to 53.6, was reading 54.6V. Sorry.

[Coulomb]

On 2023/03/12 at 10:30 PM, BTTB said:

then voltages on the inverter fluctuate up to 56V or thereabouts for about 10 minutes and then it drops to 53.5 or 54.6

My guess is that the battery has disconnected at that point, with utility powering the loads and charging an imaginary battery that is taking remarkably little current. The ten minutes convinces the firmware that the battery really is full, it's not a glitch. At that point it switches to the float voltage (I presume 53.5 V), or something causes the BMS to reconnect before the 10 minutes is up and the inverter continues in the absorb stage at 54.6 V (also presumed).

I certainly hope that's the case, as 56 V is over 4.3 V per cell (presuming 13S NMC), and the cells' maximum recommended voltage is likely 4.20 V. 54.6/13 is in fact exactly 4.20 V per cell, on average. [ Edit: But this is a coincidence; see next post. ]

Edited March 14, 2023 by Coulomb

[BTTB]

5 hours ago, Coulomb said:

My guess is that the battery has disconnected at that point, with utility powering the loads and charging an imaginary battery that is taking remarkably little current. The ten minutes convinces the firmware that the battery really is full, it's not a glitch. At that point it switches to the float voltage (I presume 53.5 V), or something causes the BMS to reconnect before the 10 minutes is up and the inverter continues in the absorb stage at 54.6 V (also presumed).

I certainly hope that's the case, as 56 V is over 4.3 V per cell (presuming 13S NMC), and the cells' maximum recommended voltage is likely 4.20 V. 54.6/13 is in fact exactly 4.20 V per cell, on average.

I think you're right.
Also, watchpower sits at 95% for a while and then jumps to 100% with the higher voltage, then the voltages drop to 53.5V or 53.6V as you describe and stays there. Every now and then watchpower says the battery is charging at 1% thereafter, otherwise 0% mostly.
Looking at the lights of the AM2, all 6 are solid and not flashing when this happens, so they aren't taking in any amperage I'd assume, the BMS would ensure this. 

I edited my original post; the voltage settles at 53.5 or 53.6 (not 54.6). 

I'd have to check with the Electrician to answer you properly.

Thanks for your input, much appreciated. 

Edited March 13, 2023 by BTTB