VE.Bus SOC Issue on GX firmware 2.42

Question

question

ngillam asked Jan 20, '20

VE.Bus SOC Issue on GX firmware 2.42

Hello,

I have 3 identical standalone systems installed in the last 2 weeks that are not calculating the SOC correctly.
(NOTE. This has never been a problem with dozens of other installs over the last several years & I suspect a recent firmware update issue but please tell me I'm wrong).

As you will see in the VRM data below, the SOC is gradually reducing each day, however the MPPT is clearly reaching float.

In the past we would slightly reduce the VEconfig absorption voltage & Float Voltage to below the MPPT charge settings (& below what was being reported in VRM for the VEBUS DC Voltage). The Multi would then "Force" SOC to value set in VEConfig resulting in regular syncing and doing a very good job.

Equipment & Firmware:
Multiplus 2 48V 5kVa - firmware 467
MPPT 150/100 Smart Solar - firmware 1.47
CCGX - firmware 2.42
No BMV Battery Montitor
No External DC Loads
No AC Coupled PV Inverters
Lead Acid Batteries

CCGX Settings:
System has Multiplus 2 set as battery montior
Note. The option "improve VEBUS SOC with Solar" is no longer visable as of a recent CCGX update
DVCC turned off

VE Config Settings:

General Tab
-Battery Monitor Enabled
-SOC when Bulk finished - 95%
-Charge efficiency - 0.85

Charger Tab
- Absorption Voltage - set slightly below MPPT voltage & voltage reported in VRM for VEBUS DC Voltage
-Float Voltage - set slightly below MPPT voltage & voltage reported in VRM for VEBUS DC Voltage

Note. I have adjusted all of the VEconfig settings several times trying to get the system to work with no success.

VRM Data:

SOC

greg-cover-graphs.jpg (344.1 KiB)

cover-charger-tab.png (29.6 KiB)

2 |3000

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

Modifications Space

Node Red Space

Answer 1 · 2020-01-20T20:16:02Z

Edgar Graadt van Roggen answered · Jan 20, 2020 at 08:16 PM

Hi Ngillam,

I saw your issue, and it is the same as the one I am having on the system I installed. I have also tried several tweaks similar to yours, but no success so far. So unfortunately I am not writing to suggest a fix. I started a similar blog under "How to get SOC to 100%" and got a few suggestions which I am trying out. If a solution pops up, I will make sure I will pass it on to you.

2 |3000

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

Answer 2 · 2020-01-24T23:20:17Z

ngillam answered · Jan 24, 2020 at 11:20 PM

I've wound back ccgx firmware to v2.33 and fixed the problem.

fixed.png (103.2 KiB)

1

2 |3000

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

Guy Stewart (Victron Community Manager) ♦♦ commented · Jan 25, 2020 at 01:08 AM

Thanks for reporting back with the work around, I’ll ask the developers to have a look.

0 ·

Answer 3 · 2020-02-10T05:27:49Z

ngillam answered · Feb 10, 2020 at 05:27 AM

Upon further investigation, the firmware roll back did not fix the issue.
(Everytime i remote upload an updated VEconfig file the system appears to "sync" once and then not again.

I have set the charge efficiency in VEConfig to 1.0.
Everyday the battery SOC drops (slightly) lower & lower.

I would have thought with the charge efficiency set to 1.0, for every 1 amp that comes out of the batteries, the system only requires 1 amp to go back in to bring the S.O.C back to where it started.

Given that the MPPT will put more back in due to actual charge efficiency (and not what is set in VEConfig), im unsure why there is always a deficit? Is this due to stand by power of the inverter?

In any instance, how does the SOC ever get back up to where it began with out syncing?
(Which is the problem i was originally posted).

NOTE. ALL LOADS ARE AC DIRECTLY OFF THE INVERTER (NO EXTERNAL DC LOADS).

2 |3000

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

question