Getting to know my Victron Cerbo GX

[fwunder]

Victron Multiplus II 5kVA x 2 split phase, Pytes V5 x 2, Cerbo GX. Currently setup as UPS backup until I convince wife to plant panels instead of asparagus.

Pretty basic questions, I'm sure.

DVCC forced on.

Every time I decide to play with MK3-USB-C and Victron Connect to mess with or review settings, unplug bus and plug back in, battery bank goes into charge cycle up to absorption @ ~56.7v or so and then drops back down to ~53.2 when the Cerbo GX continues to show Bulk. Never goes to float. Battery BMS seems to be in charge ( DVCC ) but inverters keep insisting otherwise. It's messing with me.

This is a brand new system, only a couple of days online and will be adding third battery tomorrow. Should I just give it some time to mellow out?

Thanks.

 

[Brucey]

Victron Multiplus II 5kVA x 2 split phase, Pytes V5 x 2, Cerbo GX. Currently setup as UPS backup until I convince wife to plant panels instead of asparagus.

Pretty basic questions, I'm sure.

DVCC forced on.

Every time I decide to play with MK3-USB-C and Victron Connect to mess with or review settings, unplug bus and plug back in, battery bank goes into charge cycle up to absorption @ ~56.7v or so and then drops back down to ~53.2 when the Cerbo GX continues to show Bulk. Never goes to float. Battery BMS seems to be in charge ( DVCC ) but inverters keep insisting otherwise. It's messing with me.

This is a brand new system, only a couple of days online and will be adding third battery tomorrow. Should I just give it some time to mellow out?

Thanks.

Can you leave your mk3 dongle plugged in to one of your cerbo ve bus ports? And then inverters daisy chained to the other port. Alternatively use voltage to charge and unplug comms while you are messing around.

You should be able to connect to your devices using Victron Connect on your phone to tunnel using the cerbo (versus bt), without having to unplug the ve bus.

 

[ricardocello]

Can you leave your mk3 dongle plugged in to one of your cerbo ve bus ports? And then inverters daisy chained to the other port.

You can do that??? I always pull the Cerbo connection when I use Victron Connect on the Mac or VEConfigure on Windows.

 

[Brucey]

Speculation on my part i don't have any ve bus stuff spent all my beans on sccs and panels and batteries lol

 

[ricardocello]

Every time I decide to play with MK3-USB-C and Victron Connect to mess with or review settings, unplug bus and plug back in, battery bank goes into charge cycle up to absorption @ ~56.7v or so and then drops back down to ~53.2 when the Cerbo GX continues to show Bulk. Never goes to float. Battery BMS seems to be in charge ( DVCC ) but inverters keep insisting otherwise. It's messing with me.

Ok, I assume you have CANbus closed loop control between the Pytes and the Cerbo.
If you pull the CANbus cable, the batteries won’t talk to the Cerbo, and the inverters should go into PassThru mode.
Please confirm. The inverters might shut down, I cannot rememeber.

Now you can connect the USB MK3 to the multipluses only (no Cerbo) and set whatever settings you want to.
Some of them will cause a reboot of the inverter, beware of the AC out going down for a few seconds.

Then unplug the MK3 and put the Cerbo back on the VE.bus.
Then reconnect the CANbus cable.
@sunshine_eggo may have better advice.

 

[Brucey]

I did find this part of the manual that talks about adding an additional inverter that isnt paired to the directly connected to cerbo inverters but yeah cant connect pc via cerbo.

 

[fwunder]

Ok, I assume you have CANbus closed loop control between the Pytes and the Cerbo.
If you pull the CANbus cable, the batteries won’t talk to the Cerbo, and the inverters should go into PassThru mode.
Please confirm. The inverters might shut down, I cannot rememeber.

Now you can connect the USB MK3 to the multipluses only (no Cerbo) and set whatever settings you want to.
Some of them will cause a reboot of the inverter, beware of the AC out going down for a few seconds.

Then unplug the MK3 and put the Cerbo back on the VE.bus.
Then reconnect the CANbus cable.
@sunshine_eggo may have better advice.

Yeah, closed loop. I will pull CANbus when batteries settle down.

Right now, what I find strange ( and may not be ) is Inverters are showing Absorption, but batteries are Idle.

Thanks.

 

[fwunder]

Sytem pic:

 

[ricardocello]

Yeah, closed loop. I will pull CANbus when batteries settle down.

Right now, what I find strange ( and may not be ) is Inverters are showing Absorption, but batteries are Idle.

Thanks.

What do you have the absorption voltage set to in the Multipluses?

 

[fwunder]

All values set according to:

https://www.victronenergy.com/live/_media/battery_compatibility:pytes_victron_ve_configure_setting_with_pytes_51.2v_batteries.pdf

56.8v

 

[ricardocello]

All values set according to:

https://www.victronenergy.com/live/_media/battery_compatibility:pytes_victron_ve_configure_setting_with_pytes_51.2v_batteries.pdf

56.8v

Well, hats off to Pytes for having decent documentation for Victron!

I would have my voltages way lower, however.
56.8v corresponds to 3.55v per cell.

But that’s not the issue, your battery is at 56.5 so it is in absorption mode.
All that means is that the charger is in constant voltage mode instead of constant current mode.
But your BMS has already said “No more!”, so that’s where it is stuck.

 

[fwunder]

I was wondering if I should lower voltages a bit just to make the lights go out. Nice graph:

 

[ricardocello]

I was wondering if I should lower voltages a bit just to make the lights go out. Nice graph:

Your battery cells are well balanced.

 

[fwunder]

Thanks. I think. Maybe I should just let the Pytes BMS do its thing and stop messing with things. Just bugs me that the Bulk light on the inverters is always on.

 

[ricardocello]

Lacking live Eggo at fhe moment, here’s what he has said in the past.

Post in thread 'After absorption, exporting power to grid?'

Oct 8, 2024

ABS to 55.2, time to 2 hr
Float to 54.

ESS was my next question. To answer your original question, do you have ESS configured to export to grid when battery fully charged (absorption ended, go to float)?

• sunshine_eggo

I use absorption 55.2V, 1 hour, and float 54.0V in the inverter settings.

 

[fwunder]

Thanks! I guess I can tweak some things without breaking anything.