Hi Jason,
Did you resolve the High Battery Voltage alarms? I got the same alarms after updating to v3.42 and still seeing them on v3.50 (Colour Control GX). With v3.50 the PV Inverters now appear in the device list and display on the dashboard and CCGX display.
Thanks
Hi @BC24 , I checked your system, and it has 47 high voltage alarms in the logs and first one dates back to April 27th 2024.
Definitively something you need to look into but I donāt think this is related to a GX firmware update.
That high battery voltage alarm is actually a high cell voltage alarm, sent by the BMS.
Most likely cause, first thing to check, is cell imbalance, which in itself is not a problem and normal to occur of the battery doesnāt have the option to sufficiently and often enough do the balancing. But it does need resolving to be able to have maximal usable capacity of your battery.
How to do that is documented in detail here: Victron & BYD [Victron Energy]
Hi Matthias
Thanks for checking and you response. I can enlarge on why I suspect a firmware issue. In April 24 I added additional panels, solar chargers and two additional BYD LVS modules. So it does make sense there could be a battery imbalance. However: At the time I had three existing solar chargers connected through a USB hub to the CCGX working well on firmware v2.51. The installer attempted to connect two additional solar chargers along with the existing three solar chargers (all Victron smart solar) through a new larger usb hub. It didnāt work and one of the changes we tried was a ccgx firmware update (donāt recall the version). I persisted with this firmware for a day (27 April) but it didnāt make any difference with the solar chargers and I lost PV inverter monitoring with it so went back to v2.51 on the ccgx. Solved the solar charger issue by reverting back to the original USB hub and connected the two new solar chargers using VE direct about two weeks later (you can see the solar charger error codes vanish on 14 May and no battery voltage alarms after 27 April). Got to October and the additional solar production started to exceed my grid feed in limit of 10kW so I updated the ccgx firmware to v3.42 at the time to utilise the grid feed in limit function. High battery voltage alarms appeared straightaway along with the loss of PV inverter monitoring as previously posted. I reverted back to v2.51 and the high battery voltage alarms disappeared but I went back to exceeding my grid feed in limit. Updated to v3.50 and PV inverter monitoring was restored but high battery voltage alarms returned. So there appears to be a link to ccgx firmware updates.
I will work through the information you supplied and see if that helps.
One other issue that I havenāt resolved is that none of the individual solar chargers show up in the device list on the VRM portal. On v2.51 the solar chargers show up with individual IDs 289, 290 etc but on v3.50 I just get one with ID of 65535. All solar chargers updated to latest firmware, power cycled and ccgx rebooted. Do you have any recommendations to try here.
Thanks
Ben
Hello all,
I have 2x BYD Premium LV battery (30kWh in total) and when SoC is close to 100% I also get high cell voltage warnings (not errors !).
The highest cell voltage can get up to 3.8V (if Iām not mistaken) but overall battery voltage stays within spec.
So Iām not sure if this is a Victron issue or a BYD issue.
I have the same issue, and I can see that other installation companies are experiencing it as well, at least here in the Czech Republic. The people Iāve spoken to have dozens of installations and are seeing the same problem, even on older systems. In our case, the batteries have been installed for almost six months, and Iām still getting High Cell Voltage alarms. The recommended temporary solution ā limiting the maximum voltage via DVCC ā has not resolved the problem so far.
In my opinion, this is a systemic issue. However, after one out of eight modules was replaced under warranty, BYD is now claiming that everything is fine and that this behavior is a feature, not a fault. I strongly disagree with that. The evaluation of the state of charge is performed by the batteryās BMS, not Victron. Furthermore, advanced diagnostics show that itās always a different cell in the system that has the lowest voltage. Itās as if the balance is thrown off after each cycle, and the integrated BMS is unable to fix it. And if I leave the voltage limit in place permanently ā which BYD recommends if I want to get rid of the alarms ā then the system will never reach 100% charge. Thatās just stupid.
If your low and high cell voltages from BMS reaches Cerbo, then it will be easy to implement an algorithm to dynamically reduce the charging voltage based on the high cell voltage to prevent cell overvoltage.
Then, slowly, during time, the battery will have time to balance.
A similar algorithm is implemented for Pylontech batteries, but because each type of battery BMS is reporting a different manufacturer ID, it will not work when a BYD battery is connected.
You must implement a similar correcting algorithm for BYD in the DVCC scripts.
With Charge Voltage limited to 57.6V, battery reaches 100% just fine (over here).
To put less stress on my batteries Iāve made a Node Red flow that limits the Charge Current to virtually zero when SoC reaches a specified level.
With this Iām limiting the SoC to 90%.
Every few months I let it charge all the way up to 100%.
Also Bartās solution to reduce charging current near the end of the charging process is a very good idea in the case of unbalanced batteries.
Iāve got good results when at the end of charge the current was reduced to about 1/10 of capacity (C10).
Thatās what Iāve put in my flow as well.
Basically it has 3 charge stages:
Last step is kept at 5A so Inverters still have some wiggle room to dump excess solar in the batteries when running off grid.
In my case thereās a secondary flow that limits the output of my Fronius inverters so thereās no need for frequency throttling.
Good ideas, but isnāt this the work of BYD? After all, the battery controls the charging itself, Victron listens to what the battery wants. Or am I wrong?
Anyway, I turned off the DVCC voltage limit and set the current limit to 10A. At that moment, the voltage on the battery jumped without the HCV alarm and the battery is at 100%. Very interesting.
It is, but it usually doesnāt hurt to help them a bit 
Also: Iāve installed a BMS software update on my BYD battery recently but havenāt tested if it actually changes anything in the charge process;
I have latest firmware via Be Connect app installed, but no change to charging behaviour.
Youāre right up to a point.
If the cells are imbalanced, then one cell (or more) can rocket-up and the others trail behind.
For example:
Suppose that the BMS is configured for disconnect/protect if the total battery voltage is above 58.4V (3.65V x 16) or if any of the cells exceed 3.65V.
You set the charging voltage to a conservative 56V, which, for a 16S battery, is 3.5V per cell.
At 56V, if only four cells are way ahead of the others, you can have those four cells at 3.65V or above, while the others are still behind at 3.45V.
E.g: 3.65V x 4cells + 3.45V x 12cells = a total of 56V.
This means that the battery will disconnect at the conservative 56V and refuse charging because of those over 3.65V cells, not to mention that the high cell alarm will be much sooner.
In reality much worse can happen. Only a few can trail behind. E.g: 3.65V x 10cells + 3.25V x 6cells = 56V. (6 are behind at 3.25V !!!).
In your case, it seems that BMS is configured to disconnect charging at 3.8V per cell, and you have 3 runaway cells.
The BMS has no choice but to allow charging up until one of the protect/disconnect conditions will be met.
Of course, an intelligent BMS will try to be proactive and reduce the requested voltage or at least the requested current, in order to back up a little the runaway cell(s).
This is why, like Bart said, you need to help them a bit and if they donāt reduce the limits, reduce them yourselfā¦ 
Are tou setting the BMU to on grid or offgrid set up?
They use both CVL and CCL to control charge
Has the rest been programmed and sized as recommended?
I find your complaints strange. I have the occasional high voltage alarm form different system, but they are not persistent. And have more than 60 byd units the field. The supplier has moved many units without terrible issues.
This is ongrid setup and BMU is configured as ongrid. There are 8 modules, lot of reserve for 16 kWp AC+DC coupled system.
Guys, do you have a way to control the overall charging current? The DVCC current limit only works for the MultiPlus, but not for the MPPTs. I made an algorithm that limits the charging current when finishing charging, as you suggested, but I found only the DVCC current settings in Node-RED.
