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The combination of Victron products with Pylontech lithium batteries has been tested and certified by the Victron and Pylontech R&D departments.
General information about the battery is found in Pylontech's documentation.
This manual is intended to be used in conjunction with the product manual supplied by Pylontech. It provides additional and specific information regarding integration with Victron systems.
The Pylontech includes a Battery Management System (BMS) with each battery module. This interfaces with the Victron GX device and can support multiple battery modules connected in parallel.
|Module capacity||2.55 kWh||2.4 kWh||3.5 kWh||3.55 kWh|
Victron + Pylontech can be used for the following system types:
It is essential to use the CAN-bus connection of the GX device (e.g. Cerbo GX or CCGX) with the batteries for the keep-alive signal, communication of charge and discharge limits, error codes and state of charge.
For new systems, the minimum required firmware version for the GX Device (e.g. Cerbo GX is v2.42. It is highly recommended to use the latest firmware version on all connected devices, including the GX device Inverter/Charger and MPPTs. There are regular updates to improve performance and reliability.
Legacy systems installed with v2.15 can continue to be used without upgrade as long as they do not present any issues.
As long as you are using the appropriate model for the nominal battery voltage, all VE.Bus inverters and inverter/chargers are compatible.
The minimum firmware version for new installations is 469. Though updating to the latest firmware is recommended where possible, and a necessary first step when troubleshooting issues.
These inverter/charger units must be connected to the GX device via the VE.Bus connection port.
Legacy systems installed with VE.Bus firmware 422 can continue to be used without upgrade as long as they do not present any issues.
For proper operation, the Pylontech battery needs to be able to control the charge current. Therefor it is recommended to use Victron 48V compatible MPPTs models with VE.Direct port for charging.
MPPTs with a VE.Direct port
The MPPT requires connection to the GX device to regulate charge currents as the batteries require (due to temperature, etc) To test operation, try disconnecting the GX device from the MPPT. After a time-out, the MPPT will stop charging and flash an error code on its LEDs. The error code is error #67: no BMS.
MPPTs with a VE.Can port
New Model (2019 and later) VE.Can MPPTs are also supported. Be aware that some GX devices (e.g. CCGX) only have a single CANBus interface, and that is required for the battery communications. So if you use a new VE.Can MPPT, it must also be with a GX device that has more than one CANbus interface, e.g. the Cerbo GX.
Old model VE.Can MPPTs (pre 2019) are not supported.
The charge and discharge rates are managed automatically by the Pylontech battery and GX device.
Using very large solar arrays with battery banks that are too small can exceed the limits of the batteries ability to charge and possibly lead to the BMS triggering over-current alarms.
You must have the minimum number of battery modules to supply the inverters startup inrush surge currents that charge the capacitors when the inverter is first connected, this occurs prior to any loads being connected. There is also the subsequent potential current demands of the loads connected to the inverter. It is much more desirable to have the inverter/charger overload than the battery, as the inverter will automatically recover, whereas the battery may require intervention once in a fault state.
Some suggested battery sizings for common Victron inverter/chargers are listed below. These are suggestions for reliable operation for single phase off grid and are not specified by Pylontech.
Using the above formula, an example of minimum system sizing based on the US2000B Plus battery module is below. Each battery module is approximately 50Ah at 48V, can provide 25A continuous charge and discharge and 100A peak for 1 minute.
|Inverter / Charger Model||Inv continuous watts @ 25 degrees||Inverter peak watts surge rating||Number of Pylontech modules||Battery continuous discharge watt rating||Battery peak discharge watt rating|
You can connect multiple battery modules together to form a single large battery by connecting the RJ-45 cable supplied by Pylontech using the link ports on the battery. This is shown in more detail in the example wiring diagram and Pylontech manual.
The communications for UP2500 can be paralleled up to 20 modules per string (and cannot use the LV-HUB). Other models can connect up to 8 battery modules (see Pylontech data sheets), in those models when using more than 8 parallel units, some limitations, additional configuration or equipment (e.g. Pylontech LV-Hub) may apply. See your Pylontech dealer, and Pylontech documentation for more details.
The batteries will automatically detect and link to each other, no adjustment of dip switches on the battery module are necessary.
The battery with the empty link port 0 is the master battery. You must use the VE.Can to CAN-bus BMS type B Cable, part number ASS030720018, you cannot use the cable supplied by Pylontech.
Plug the type B cable with the side which is labeled Battery BMS into the Pylontech CAN port of the master battery. Plug the side labeled Victron VE.Can into the GX device.
Then, plug a VE.Can terminator in the other VE.Can socket on the GX device. Two VE.Can terminators are included with the package of the GX device as an accessory, only one is used. Keep the other one as a spare.
More information about the cable can be found in its manual.
Without properly connecting this cable, the battery will not show up on the display of the GX device. The battery will also turn itself off.
It is important to ensure this connection and display of the battery on the GX device display before attempting firmware updates or settings changes on other devices if they depend on the power supply from the battery. Without this connection, the battery may turn off unexpectedly.
On the GX device,
After properly wiring and setting the correct CAN-bus speed, the Pylontech will be visible as a battery in the device list. If you have multiple batteries a single entry will show up, which represents all batteries:
When the battery is correctly connected this will also set the following values automatically:
|Venus Settings → System Setup Parameter||Value|
|Shared Voltage Sense||OFF|
|Shared Temperature Sense||OFF|
This parameters page is also a good place to check that all batteries are connected and working properly. In see the individual battery data sheet for the normal working conditions, e.g. the current limit per cell. For example, If each battery is rated to 25A charge current, and the menu shows a 75A charge current limit ( 75 / 25 = 3 ) means there are 3 Pylontech battery modules connected.
Note that 'details' menu of the battery (e.g. Lowest and Highest cell voltages etc) is not currently supported by Pylontech.
When using the latest firmware on all compatible connected devices, and once the battery module has been detected by the GX device, battery charging parameters (e.g. Maximum Charge Current, Target Battery Voltage, etc) are automatically configured by the Pylontech BMU, and communicated to the rest of the Victron components in the system via DVCC.
It is possible to override some of these automatic settings to provide additional limitations (e.g. reduce the total charge current that would be provided but the MultiPlus). The following information is provided for that purpose, though is not required for the safe operation of the system.
This section presumes familiarity with VEConfigure software.
Voltages shown are for the 48V model, and should be divided for the 24V model.
|Absorption voltage||52.0 V|
|Float voltage||51.0 V|
|Absorption time||1 Hr|
Note: make sure to double check the float voltage after completing Assistants, and if necessary set it back to 51.0 V.
Note For off-grid use: ignore the 'bms assistant required' warning.
In the Inverter tab of VEConfigure
|VEConfigure Inverter Parameter||Setting|
|DC input low shut-down||44V|
|DC input low restart||48V|
|DC input low pre-alarm*||48V|
* The pre-alarm setting is dependant on your preference and on site specific requirements. You may wish for this to be activated earlier in an off grid situation to allow time to start a backup generator.
The settings that are specific to the Pylontech battery in the VEConfigure ESS Assistant are below:
Select the externally managed Lithium battery option
|Dynamic cut-off values||set all values to 46V.|
|Restart offset:||1.2V (Default)|
Due to the reliability of the grid supply and the behaviour of the sustain voltage threshold in ESS; you may wish to suppress the low voltage pre-alarm warning so that it does not trigger every day on its regular deep cycle. See ESS FAQ Q5 - about suppressing the low-voltage alarm.
In normal operation, the charge parameter limits are set by the Pylontech battery and communicated through the system by the GX device to the inverter/charger and MPPT.
If operation is attempted outside the operating range, the battery will disconnect to protect itself.
In normal operation the MPPT charge characteristics are governed by the GX device via DVCC, with instructions from the connected Pylontech battery.
This section presumes familiarity with VictronConnect
The settings below can be set as a precautionary measure.
If the system is not operating correctly, go through these steps.
As a safety precaution, the inverter/charger will not switch on if the GX device is not on. If you are unable to start the system due to a total system blackout / battery shutdown due to low voltage, you may need to disconnect the VE.BUS connection cable between the inverter/charger and GX device.
You can then start the inverter/charger from an external charge source such as a generator or grid connection. Once the inverter/charger has started, it should supply power to the DC terminals and this should start the GX device and Pylontech battery again. You will need to then reconnect the VE.Bus Communications cable back to the inverter/charger and GX device.
If its not visible, check:
Check the Max Charge Voltage parameter. This voltage parameter is sent, together with the other three parameters, by the Pylontech system via the CAN-bus cable. They are visible on the GX device: Device List → Pylontech battery → Parameters menu.
The Pylontech manual contains additional diagnostic and troubleshooting information, specifically around decoding any indicator LEDs.
The maximum current is limited to keep the battery healthy and reach the 10 year guarantee. In off-grid, the inverter can draw more than the 25A limit to run the loads, make sure you have sufficient batteries installed to keep the load per battery around this limit.
This is caused by cell balancing inside the battery. This happens with new batteries and after a deep discharge.
Pylontech's BMS will restrict the Charge Current Limit of the battery in cold weather. The precise temperatures and limits are not published by Pylontech, but anecdotally from reports on Victron Community it would appear that batteries begin to be limited below 18 degree C, severely limited below 10 degrees C, and completely restricted from charging below 2 degrees C.
You can confirm if this is affecting your installation be entering the Pylontech Battery menu on your GX device, and then the Parameters Menu. This will report the Charge Current Limit (CCL) and Discharge Current Limit (DCL). This information is also logged in the advanced section of the VRM monitoring portal.
When DVCC is enabled, the battery (via the CAN-bms) is responsible for the charge voltage. The Pylontech battery requests a charge voltage of 53.2V. We have however found that in practice this is too high.
The Pylontech battery has 15 cells in series, so 53.2V equates to 3.55V per cell. This is very highly charged and makes the system prone to go overvoltage.
It should also be noted that a LiFePO4 cell stores very little additional energy above 3.45V.
For this reason we opted to override the BMS and cap the voltage at 52V. This sacrifices almost none of the capacity and greatly improves the stability of the system.
Also see the question above. The state of charge of the battery is estimated based on the overall voltage and on how well balanced the internal cells are. Because we cap the battery voltage at 52V, the state of charge will sometimes rise very slowly once it reaches the mid-90s. This is normal and usually resolves over time.
For information about where to buy or find suitably qualified installers, visit the Where to Buy Page.
Further community discussion about installing and using Pylontech and Victron can found at Victron Community, use the topic label 'Pylontech'.