Pylontech US3000C / Venus GX / MPPT 150/35 High voltage alarm at 49.14V

Question

question

technology asked Mar 3, '23

Pylontech US3000C / Venus GX / MPPT 150/35 High voltage alarm at 49.14V

Hi,

We have a new off grid solar install reporting Solar Charger [258] - Error code: #2 - Battery voltage too high, and is not charging battery, it is discharging and powering its load.

PylonTech US3000C

Venus GX, Firmware 2.93

MPPT 150/35, Firmware 1.47

I have read the info at: https://www.victronenergy.com/live/battery_compatibility:pylontech_phantom#high_voltage_warning_or_alarm_shown_on_battery_status

about this alarm being caused by imbalanced cells on newly installed batteries, but I don't think this is the case.

System reports Pylontech battery voltage 49.14V

Highest and lowest cell voltage reports 3.276, and battery gives OK accross the board.

Battery CVL auto set by pylontech to 53.2V

I have tried the advice linked above ("Note: The “Limit managed battery charge voltage” feature should be left OFF, unless you are experiencing “High Voltage” or “Internal Error” alarms. These alarms can indicate that there is an internal cell imbalance in the battery. It may be useful in this situation to enable this feature, and then adjust the voltage limit down so that the batteries are able to balance charge without reaching over voltage internally. ")

adjusting the Limit Managed Battery Charge Voltage all the way down to just above the voltage reported by the battery, and rebooting the Venus GX, but the high voltage alarm returns immediately after boot.

What is the next step to resolve this over voltage alarm and failure to charge?

Cheers

Pylontech

1677884982021.png (32.8 KiB)

1677885038837.png (41.3 KiB)

1677885120748.png (36.1 KiB)

1677885133054.png (34.7 KiB)

1677885189546.png (30.6 KiB)

1677885591010.png (41.5 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.

technology answered · Mar 06, 2023 at 01:09 AM

Got it.... victron connect was not even listing the MPPT charger, because VRM 2 way comms was not enabled on the Venus GX..... Ugh.

Enable VRM 2 way communication on Venus GX (Settings > VRM Online portal > VRM 2 - way communication)

Victron Connect > VRM > *the site* > Devices then lists the Charger, and clicking it prompts to update chargers firmware. Alarm goes away, pylontech battery charges....

1678064843621.png (69.9 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 · 2023-03-03T23:34:44Z

matt1309 answered · Mar 03, 2023 at 11:34 PM

Hi @Technology

I might be miles off here but what are the settings you've got within the charge controller itself. If the error is coming from the charge controller is there maybe a voltage setting in there that is incorrect.

I'm not too familiar with pylontech but just googled and can see they have 15cells in series. Many LiFePO4 battery packs use 16cells in series. If you've used default settings for LiFePO4 in MPPT you might have set absorption/float voltages too high for a 15cell battery pack, hence why voltage is peaking.

(Sorry if you already know this but this is the logic behind my guess):

It's worth noting that if cells are unbalanced they'd likely peak when charging and might drop down to a "normal voltage" when charge controller disconnects/stop charging (and balances kick in). However i don't think that's the case here as your cells seem a fair way under a high voltage. 53.2/15 = 3.55 per cell and yours are sitting at 3.27 per cell without being charged.

If they were 3.3-3.4v without charging then i'd maybe agree it was unbalanced cells and as soon as you added charging the 3.27 might peak to 3.55+ quickly, but 3.27 is a fair way off the steep part of the curve for LiFePO4 batteries in my opinion (i'd say 3.45 is the start of the steep part for most). So my guess is it's not due to unbalanced cells and instead maybe incorrect settings in MPPT.

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 · 2023-03-04T00:59:54Z

technology answered · Mar 04, 2023 at 12:59 AM

Hi Matt,

You might be onto something there. From the remote console in the VRM portal I can see the MPPT Charger via the Venus's Ethernet connection (which I would take to mean the VE.direct comms from Venus GX to the MPPT charger are good):

It looks like the charge voltage is being set correctly by the BMS:

I can not edit the values from this screen, and would normally expect to be able to from the Victron connect app, but the MPPT Charger is not listed as a device connected when I view this site:

Any ideas why The Venus GX would list the Charger, and its firmware, Serial number etc, but I would be unable to edit its settings via Victron Connect?

Thanks

1677891286178.png (36.2 KiB)

1677891480599.png (40.4 KiB)

1677895343406.png (39.2 KiB)

12

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.

JohnC ♦ commented · Mar 04, 2023 at 02:56 AM

@Technology

Try using the Remote method (VC-R). You select VRM rather than Local.. https://www.victronenergy.com/media/pg/VictronConnect_Manual/en/victronconnect-remote--vc-r----configuration-and-monitoring-via-vrm.html

0 ·

technology JohnC ♦ commented · Mar 04, 2023 at 03:00 AM

Hi John,

That gives the same result I'm afraid. VRM > *The site in question* > devices: No devices listed at all.

0 ·

JohnC ♦ technology commented · Mar 04, 2023 at 06:11 AM

@Technology

Do you get this screen?..

VRM is selected (the thin red line under the blue), and VRM is ticked Online. When that CCGX selection is clicked it will load a list of the available devices on that installation, whether it's local or remote. This is with a WinPC.

0 ·

1677909785170.png (21.4 KiB)

technology JohnC ♦ commented · Mar 04, 2023 at 09:44 AM

I do get that screen, once I select the site, there are no devices listed:

0 ·

1677923004108.png (35.6 KiB)

1677923054986.png (37.8 KiB)

klim8skeptic ♦ technology commented · Mar 04, 2023 at 09:53 AM

Perhaps you could update the firmware in your mppt above v1.47 ??

1 ·

technology klim8skeptic ♦ commented · Mar 04, 2023 at 08:55 PM

I am unable to communicate with in in a way that allows a firmware update. I would normally be able to do this through victron connect app I believe?

0 ·

matt1309 technology commented · Mar 04, 2023 at 09:28 PM

Does it work using local/bluetooth connection rather than via VRM?

Yes if MPPT is connected to venus/cerbogx it should appear within devices under that VRM device. When you click on the device a go to settings and you should see "update available" message.

0 ·

technology matt1309 commented · Mar 04, 2023 at 11:26 PM

Cheers for the response,

The only way I can see the Venus GX in the app as local is to connect to the venus GX's wifi. It then shows the Venus GX, but still zero devices listed.

Bluetooth does not detect any local devices, using both victrons instructions to search via the app on android / iphone bluetooth, and android / iphone bluetooth settings pair device.

Neither the MPPT or the Venus GX has a ve.direct bluetooth dongle connected, previously we had not required this to get these devices talking, nor do I have one on hand.

0 ·

matt1309 technology commented · Mar 05, 2023 at 12:58 AM

Nightmare, sorry that's where my knowledge falls down sorry, the devices I'm familiar with have Bluetooth built in so I've not ran into this issue before.

Out of curiosity how did you input the settings into MPPT to begin with (absorption/float voltages etc). Just checked the manuals and seems to say you need bluetooth dongle or VE Direct USB cable.

I imagine that is the solution to upgrading firmware and also checking the voltage parameters in the charge controller that might be causing your issue.

0 ·

technology matt1309 commented · Mar 05, 2023 at 06:00 AM

In this setup the Pylontech BMS is given control over charging paramaters by connecting it to the CAN port of the Venus GX.

The MPPT charger (viewed through the Venus GX) recognises that the charge paramaters are to be controlled by the battery:

0 ·

matt1309 technology commented · Mar 05, 2023 at 10:58 AM

That's me out of ideas then sorry. Maybe worth trying to see what highest cell voltage is when you turn off and turn on mppt (so you can see what happens before the error message appears).

That way you'll be able to confirm if there is a cell peaking in voltage and unbalanced pack is then confirmed to be your issue.

0 ·

matt1309 matt1309 commented · Mar 05, 2023 at 11:00 AM

If you can I would still try log into mppt to make sure its actually reading the settings from pylontech correctly as I still suspect that mppt settings might be part of the issue rather than unbalanced cells

0 ·

question