BYD Image


SOC drops slightly every 7 hours



I recently install 3 x 4kw new BYD LVLs to an existing system on grid that had 3 x 4kw BYD LVLs so a total of 6 (two towers of 3) with a Victron Quattro 48/10000/140. I since I installed the 3 extra batteries my system as been slightly dropping SOC to 99.5% every 7 hours without any change in load or mains loss. What settings can I check to see why this is happening all of a sudden? Let me know if you need further screen shots of any parameters.

Update: I have fully bypassed the inverter so there are no loads and it still dropped SOC slightly on the 7 hour mark and went into bulk charge.

Update 2: did a discharge test all worked ok, went down to 20% SOC, charged back up to 100% and it went back to every 7Hrs issue again. At a loss.

sdc88 asked
sdc88 commented ·

5 Answers

AC current limit

Does reducing the AC current limit effect the ability for AC connected solar on the system output to push back to the grid? Is it bi directional whereby causing over charge issues?

paul-ham asked
sharpener answered ·

1 Answer

BYD Premium LVL 15.4 - weird approaching to 100% SOC while charging2

This has already been posted once, and I am seeing the same behaviour, triggered by the BYD BMU (2x, 30 kW). Reaching 100% SOC, there is a discharge spike of about 250 A (13 kW).


This results in a brief grid export of 13 kW. I am limited to 4 kW. Any idea how to make this stop?

luupus asked
anthony answered ·

1 Answer

AC Coupled ESS minimum battery size


We are installing a AC Coupled 3 Phase ESS (Grid Connected) system with 15kW 3P Fronius connected on Output of 3 x 5kVa MultiPlus II. Were planning on installing approx 30kWh of BYD lithium, however i noticed on the Victron AC Coupling & Factor 1.0 rule page there is also a minimum battery size required. (in this instance it is 48kWh)

Can anyone explain this?

30kWh of BYD will deliver 30kW of power & accept up to 20kW of charge.
If the PV inverter was on the Input of the Multi the minimum battery size 3 x 2.5kWh modules acording to the Victron/BYD guide.



Nick Gillam asked
leighandchris1 answered ·

5 Answers

Error code: #67 - No BMS since 6 months

Since 6 Month i have the problem, that my plant get the Error code: #67 - No BMS.

This only happens when the Batteries getting full (100 %). After this Error the Charger turns the PV Panels complete away and i have no more charge.

The plant is running but without the pv panels. The only thing i can do is to reboot the plant and after the reboot everything ist ok.

MultiPlus-II GX – v 2.73

MultiPlus-II 48/5000/70-48 – v 481

SmartSolar Charger MPPT 250/60 – v 1.59

BYD Premium LV battery – v 1.20


When it's working:


After the Error:


Maybe someone can help me with my problem, cause my plant is a pv off-grid photovoltaic system and iam not constant there.

Thank You and greetings


karlmelichar asked
mmb answered ·

6 Answers

Why connect the Negative DC battery terminal or busbar to Ground?


What is the reason why negative busbar and grounding busbar are common? How can we protect the system against impacts from the soil in this case?


cagataysahinoglu asked
T F answered ·

2 Answers

CCGX doesnt detect all BYD Battery modules

Hello everyone

I recently upgraded a perfect running system with 1-phase multiplus and 1 BYD Box Pro 4x 2.5kWh battery,

with a second BYD Box Pro with 4x 2.5kw battery.

I have addressed and connected all the batteries correctly.

However, it works when I connect the BMU to CCGX, the limit charge and discharge current is 140A, it only seems to recognize a maximum of 4 batteries)

No matter how I combine the batteries, new and/or old. (of course always correctly addressed)

Only 4 are recognized. The remaining 4 batteries showing a scrolling LED light. (dip switches are ok configured, also COM cables ok)
BMU from first BYD box mit BMU from second BYD Box changed = same effect

Thanks Michael

guru2431 asked
guru2431 commented ·

1 Answer

CCGX not detecting all the connected BYD battery modules

Hi, Every one

I recently setup a system with 3 Phase Quattro configuration and 16 of BYD Box L 2.5 kWh batteries.

I addressed all the batteries and connect to a BYD Box pro 10 BMU.

( I bought 1 BYD Box pro 10 panel with 4 batteries and 12 single batteries).

It works, however, when I connect the BMU to CCGX, the limit charge and discharge current is 140A, it seems only know 4 batteries, and the max voltage is 56.5 and min is 43.)

I just wonder whether I have to buy another BMU to manage total 16 batteries?


john2019 asked
nickdb commented ·

3 Answers

Smart Solar MPPT doesn't resume charging after full charge is met.


I have a problem. When the batteries reach 100% the Smartsolar's stop working and the batteries start draining. This happens everyday.

We have 4 x BYD LVL modules, 3 x 250/70 and 3 x 15kva inverters setup as a 3 phase off grid system.

DVCC is forced on and cannot be changed. The MPPTS are ex control.

When the smartsolars stop working, the parameters on the batteries still show a charge limit of 900A so I feel it's not an issue with the BMU for the LVL's.

We are abit stumpted, any idea welcome


max-branson asked

0 Answers

Adding Victron to existing grid-tied Gen24 + BYD HVS system

I have an existing grid-tied system with a 7kW of panels to a Primo 6kWh Gen24 with 7.7kW of BYD HVS hooked up.

I would like to add a 48V Victron to the system and add batteries, probably Pylontech, and I will be adding a wind turbine to this system, but not initially. What would be the best setup to not mess with my current setup too much, but such that I can fill the Pylontech batteries from both the grid and the panels?

travellinground asked
Frank commented ·

1 Answer

Quattro shuts down without any warning/alarms

Hello everyone.

Here's my setup: Quattro 8kva with a Fronius 8.2kw on AC OUT and 2 MPPT150/45, and a BYD LVS 32kWh (8 modules).

I have forever had an issue with high voltage alarms (reference topic and this never changed after 1 year. I have tried keeping the grid/generator for 2 days, set the charging voltage to 55 in DVCC (works until it is removed), and none solved the issue.

That's not my problem however, it's fine, a warning I can live with. Last week, I finally got approved for net metering and our grid company installed the meter so I can start feed-in. All was well and good until the system starting shutting down. Nothing in the alarm log or events, except for the usual high voltage alarm.

Here's what happened:


1. batteries full, grid offline

2. at some point grid came online, feed in started, max cell kept going up

3. first shutdown

4. second shutdown, after that I disconnected the grid

I am making the assumption that this shutdown is from the BYD BMU because of the high cell voltage situation, plus the Quattro doesn't register any other alarms/warnings/events.

My first question is, why at point 2, the high cell voltage kept rising? Batteries are full at this stage and I am feeding the excess back to the grid (only AC excess, not DC).

I have for now set DVCC charge voltage limit to 55V and waiting for the grid to come back online and test this.

Does any fellow Victron user have other thoughts or experience with this?

micmak asked
micmak commented ·

0 Answers

BYD LVS - Strange increase of "min/max voltage" difference after 100% charge

Hello everybody,

I have an offgrid system, running for 1 year, made of a 8kWh BYD LVS battery, a MPPT RS450-100, and a Multiplus II 5000 VA.
Everyday, after the battery reaches 100%, I observe a strange increase of the max cell voltage, during hours :


Is it normal ? Does anyone have an idea of what happens ? The BMS should be balancing the cell's voltage instead, no ?

Thank you very much for your help

bluefab asked
micmak answered ·

3 Answers

BYD / Victron set up. 150/70 MPPT + 250/60 MPPT - How to prioritise ?

Have a client with a BYD / Victron set up. Has a 150/70 controller for solar. 250/60 controller for hydro. The 250/60 is set up with using relay to divert load when BYD doesn't need anymore power. Diversion is done by a 230V relay from the power system to electric underfloor heating.

Problem: When diversion is active and it's sunny the system clips the 250/60 and uses the 150/70 to power the diverted load which I need to keep the 250/60 with load to stop over spin of the hydro.

Question: How do you prioritise one MPPT over another MPPT when EXT controlled by BYD/GX?

electrical-revolution asked
electrical-revolution answered ·

2 Answers

Battery voltage limit

We have a couple of Multiplus v2 5k, a 5k AC coupled Fronius, 4 BYD b-box LV 48v batteries and a Cerbo to tie it all together.

Now I want to limit the charging voltage on the BYD batteries from 58.4 volt to 56.4 volt. According to Will Prowse this will greatly increase battery lifetime. Please correct me if I'm wrong.

I have no idea how to do this. In Venus OS, the CVL option under the BYD parameters is not changeable. Do I need to do this in the BYD software somehow?

Thanks in advance,


yagu asked
nickdb commented ·

3 Answers

Error 17 master failure when Grid fails aka Loadshedding.

We have a Few Installations that have 2 or more multiplus II's where we have the system work perfectly until the grid fails, at this point we get error 17 master failure.

We Have victrons rj45 cables cables between the Multipluses and colour control. They have been checked.

The wiring is all the same length.

We have updated the firmware to latest.

The fuses are fine.

The colour control has been replaced at one site, but it still happened.

Is there any other advise?

This has happened at multiple sites now with multipluses in parallel.


dylan asked
stingerb answered ·

6 Answers

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