question

Wayne avatar image

OCTO GX - 4 BlueSolar MPPT - system voltage issue

Hi there

I have 2000W solar through 4 BlueSolar MPPT's 3x30 1x60amp with VE Direct cables to my Octo GX, also connected is my 12/3000/120 Multi.

Batteries are 2x RB300Ah Relion lithiums.

I have a BMV712 smart also connected to the Octo via VE Direct.

I am having the same issue as many with the MPPT battery voltage being different to the BMV voltage, I can see my controllers going to float as low as 70%SoC.

I have been told if I instal a Bluetooth sensor to the battery bank and network it to the BMV712 that this will become the default voltage for the entire system, has anyone done this with an Octo or can confirm it is correct.

TIA

Wayne

battery system voltagesystem integration
2 |3000 characters needed characters left characters exceeded

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

3 Answers
JohnC avatar image
JohnC answered ·

Hi @Wayne

I can't answer your specific query re networking in a BT V-sensor, but it shouldn't really be necessary to do that.

The Octo has DVCC, designed for sharing such data with all VE.Direct devices. https://www.victronenergy.com/media/pg/2556-GX_Device_Manual_Cerbo_GX/en/dvcc---distributed-voltage-and-current-control.html

The BMV's V is likely the default source, and all mppt's should get that supplied to them. Without BT.

How this works in with your battery's BMS might need checking, but you haven't mentioned a bms..

That's the SVS option, the STS you shouldn't need with Li's, and SCS may also be useful for Absorb/Float switching.


2 |3000 characters needed characters left characters exceeded

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

seb71 avatar image
seb71 answered ·

"I am having the same issue as many with the MPPT battery voltage being different to the BMV voltage, I can see my controllers going to float as low as 70%SoC."


The conditions for the MPPTs to switch to float have nothing to do with the BMV SOC displayed value.

2 |3000 characters needed characters left characters exceeded

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

Wayne avatar image
Wayne answered ·

JohnC you were on the money.

Thanks so much, I have been able to use DVCC to point the Multi temp sensor as the default for the system and the same with the Voltage from the BMV as the default for the system.

Did a reboot of the Octo and all the MPPT V's have come into line with the BMV and all have gone to bulk and working as they should.

Thanks again!!

2 |3000 characters needed characters left characters exceeded

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.