question

Chethan Bandi avatar image
Chethan Bandi asked

Pylontech High Voltage Alarm US3000

Hi,

We have just replaced batteries with Pylontech US3000 x 2 on an existing off grid solar system. We are getting a high voltage warning with the SOC at 81%. We have updated all the firmware to the lastest release as directed on the victron and pylontech page.


Here are the details of the system


Victron easy solar with 48V, 3KVA Multiplus, 150/70 blue solar MPPT, 2 x US3000 Pylontech Batteries.


Firmware Versions

CCGX - V2.63

MultiPlus 3KVA - V2620459

MPPT 150/70 - V1.54

VRM Portal ID - 508cb1e4251b


Please Help

Pylontechoffgrid
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3 comments
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seb71 avatar image seb71 commented ·

At what battery voltage you get that alarm?

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Chethan Bandi avatar image Chethan Bandi seb71 commented ·

@seb71 I am getting an alarm between voltage range 50 and 52

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seb71 avatar image seb71 Chethan Bandi commented ·

Your Absorption voltage might be too high.

Charge Voltage Limit should be 52.4V, not 53.2V (unless the Pylontech always reports 53.2V, even with the voltage override).


PS

Did you added those images later or I missed them?

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3 Answers
Guy Stewart (Victron Community Manager) avatar image
Guy Stewart (Victron Community Manager) answered ·

Hi @Chethan Bandi,

This alarm is usually caused by an internal cell imbalance within the lithium battery.

There are several things you can do, depending on what is available to you.

The first thing I would do is safely isolate the batteries, so they are individually connected at a time, and then charge them both to 100% one by one.

You may find that this immediately identifies one of the modules as being more 'out of balance' than the other.

If both batteries are able to be charged to 100% individually without alarms, then reconnect them (while both are fully charged to 100%) together in parallel and see if that resolves the issue.

If one, or both batteries do not reach the 100% charge state without alarms, then they will need to be balanced. The cell balancing occurs at the top end of the charge cycle. So bring the batteries up to the point where there is alarm, and then restrict the current to a slow trickle, only a few amps. You can do this by setting a manual charge current limit in the DVCC menu of the GX device. This should allow the battery to balance charge without triggering further alarms.

Depending how imbalanced the battery is, this could take a long time.

We are working on tools from our end to help improve this process, but for now I believe this the best way.

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Brandon avatar image Brandon commented ·
Hi @Guy Stewart (Victron Community Manager),

Wondering if any tools been developed yet to help with this cell balancing? One of my new UP2500 is taking a very long time and proving to be tricky.

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CristiMV avatar image
CristiMV answered ·

As already mentioned, and also personally experienced, this is normal with new commissioned batteries. Be patient, in 2-4 days this should go off, as cells will be balanced. You can also check this using the Pylontech software BatteryView (you will need a console cable for this).

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raymiller avatar image raymiller commented ·

Thanks for this info, I had the same problem with a Pylontech UP2500 24V 2.8kWh battery. It would seem if the battery does not get charged from the time of production to install, (the time in my case was >14 months) the cells can become unbalanced, which shows up on the first full charge and gives a battery alarm of "high cell voltage" well below the recommended charge voltage of 28.4V.

I also needed the BatteyView software and rs232 cable into the console socket on the battery to find out all the cell voltages. To successfully equalise the battery I needed a constant current power supply set to 100-200mA (very much a very low current for a 111AH battery) and the voltage set to the charge voltage (in my case 28.4V). The current settings for your battery may need to be more or less adjust by observing the rate of increase of the highest cell voltage reported from the BatteyView software.

From the downloaded data from the battery, it would seem the charge current needs to be just enough to prevent cell/s with the highest voltage to maintain just under 3.60Volts. Very gradually (can confirm days) the other cells increase in voltage and the SOC increases also. Of note is the cell/s with the high voltage suddenly decrease as the remaining cells reach full charge. The end of successful 100% charge seems to be <100mA and 28.4V, with the top battery LED flashing slowly indicating an idle state.

I hope this additional information is helpful.

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ewalderasmus avatar image
ewalderasmus answered ·

@Chethan Bandi


Is the alarm continuously there and you cannot clear it? or does it clear when the inverter is on? and reoccur every 3 days?

regards Ewald

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Chethan Bandi avatar image Chethan Bandi commented ·

@ewalderasmus

Yes the alarm is continuously there

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