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Help with Victron Multi Plus Firmware Settings using 3.2 V prismatic batteries

Greg55618688

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Mar 16, 2021
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13
Hello,

I’m a solar rookie and I’m almost ready to fire up my first system on my RV conversion project (fingers crossed).

I’m running 1260 watts of solar (six 210 watt panels), a 24 volt battery bank consisting of 16 LiFePo4 CATL 3.2 V 271 ah cells, Victron 150/60 MPPT, Victron 24/3000/70-50 Multi Plus, Orion 24/12 DC/DC converter, Electrodacus SBMS0 mainly to keep the cells balanced.

I have not hooked up the batteries yet or performed the initial Multi Plus firmware update and related firmware setting changes.

I came across a video that showed the Multi Plus firmware settings.
I reviewed the Victron Multi Plus Service Manual document and it does not provide the specific information related to each option that I expected would be necessary and important in order to make sure each setting is setup correctly for safe and successful functioning. Many of the settings I couldn't even come up with a reasonable guess as what to enter.

If anyone has ever setup a similar Victron Multi Plus and LiFePo4 prismatic battery system would you be kind enough to provide the Multi Plus settings which are working successfully for your system?

I know there are a lot of setup sections and I apologize for this HUGE ask, but since Victron components and these CATL, EVE, Lichen prismatic type batteries are so popular, I”m sure many others will also benefit from this information too.

Multi Plus Firmware:
General Tab Setting Options:
System Frequency
AC1 Input Current LImit
Current Limit Overruled by Remote
AC2 Input Current Limit
Overruled by Remote
Dynamic Current Monitor
Battery Capacity
State of Charge When Bulk Finished
Charge Efficiency

Grid Tab Setting Options:
Accept wide input frequency range
UPS Function
AC Low Voltage Disconnect
AC Low Voltage Connect
AC High Voltage Connect
AC High Voltage Disconnect
Country/Grid code standard

Inverter Tab Setting Options:
Inverter Output Voltage
Ground Relay
DC Input Low Shutdown
DC Input Low Restart
DC input low pre-alarm
Low SOC shut-down
AES
Start AES when load lower than
Stop AES when load higher than
AES type
Power Assist
Assist current boost factor

CHARGER tab settings options:
Enable Charger
Charge Current
Absorption Voltage
Float Voltage
Repeated absorption time
Absorption time
Charge Curve
Lithium Batteries
Storage Mode
Use equalization
Weak AC Input
Stop after excessive bulk

AC INPUT CONTROL tab settings options:
Conditional AC input connection
AC Input connection based on load
Connect when load is higher than
Delay before connection
Disconnect when load is lower than
Delay before disconnect
Battery Conditions:
Connect when SOC drops below
Connect when battery voltage drops below
Delay before connection
Disconnect AC input on
Disconnect when voltage is higher than
Delay before disconnection

Thanks, Greg
 
Pretty much only the Charger tab is dependent on your specific batteries. Using the LiFePO4 defaults is generally a good start. Turn on the "Lithium Batteries" option on the Charger tab. Set an appropriate "Charge Current" for your battery. The spec sheet on your cells should mention a recommended charge current.

Pretty much everything else on the other tabs is specific to your environment and other components.

Do you have a Victron Smart Shunt or BMV-7XX?

Are you in North America or elsewhere?
 
Hello RMADDY, thanks for your response. I really appreciate it.

I didn’t realize it mattered, but I also have the Victron BMV-712 device, and I am in the United States.

Thanks, Greg
 
It would be better if you showed your current settings. Otherwise, only folks with your exact system can help, and even then its a big ask for them to input all of their settings.
 
Section 5.1 in your manual lists the settings as the MultiPlus comes from the factory. Section 5.2 explains what each of those setting does. Battery chemistry is the main setting you need to change. Also, be aware that AC current limit is set at 50amps from the factory and should be changed to match whatever AC input wiring/breaker you have, for instance 15 amp if you are plugging into a typical house outlet.

Giving you a list of my settings would do you no good, especially the conditional settings, as my conditions and your conditions are not the same.
 
I also failed to mention, I bought the CATL batteries through Alibaba. I went back to them for the battery spec information and the attached document was provided. To me, this document along with Victron's documentation aren't clear enough to help me determine which firmware questions are mandatory and how they should be setup.

Thanks, Greg
 

Attachments

  • CATL 271.pdf
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Make sure the BMV is all setup first. Setup VE.Networking on the BMV too.

Multi Plus Firmware:

General Tab Setting Options:
- System Frequency: 60Hz for North America
- AC1 Input Current LImit: Set to 15, 20, 30, or 50A depending on your shore power connection or whatever is connected to the AC input
- Current Limit Overruled by Remote: Enable this if you have a digital multi control or some other way to control the current limit externally
- AC2 Input Current Limit: same note as AC1
- Overruled by Remote: same note as AC1
- Dynamic Current Monitor: That's up to you and your uses
- Battery Capacity: No need to enable battery monitor since you have the BMV. Just be sure to setup VE.Networking for all your Victron stuff
- State of Charge When Bulk Finished
- Charge Efficiency

Grid Tab Setting Options: The defaults are probably fine

Inverter Tab Setting Options:
- Inverter Output Voltage: 120V
- Ground Relay: Enable
- DC Input Low Shutdown: Pick a value to protect your battery or pick a value to leave some battery left to run other DC loads. Mine is set to 26V which is roughly 30% SOC. I wouldn't go lower than 24V.
- DC Input Low Restart: Needs to be higher than the low shutdown
- DC input low pre-alarm: Higher than low shutdown, a little lower than low restart
- Low SOC shut-down: If this is enabled, pick values based on the DC Input Low Shutdown using the same logic
- AES: Enable if your inverter use is infrequent. If your inverter use is constant then this gains you nothing.
- Start AES when load lower than: The default is a good start
- Stop AES when load higher than: The default is a good start
- AES type: Search mode
- Power Assist: Enable if you think you have the need. Depends on your own use of the inverter
- Assist current boost factor:

CHARGER tab settings options:
- Enable Charger: Enable
- Charge Current: 100A should work for those batteries
- Absorption Voltage: 29.2 is absolute max. 28.6 might be a better choice
- Float Voltage: 27.2V
- Repeated absorption interval: Default
- Repeated absorption time: Default
- Absorption time: Default
- Charge Curve: Fixed
- Lithium Batteries: Enable - do this before other settings
- Storage Mode: Disabled when Lithium enabled
- Use equalization: Disable
- Weak AC Input: Disable. Enable if your situation warrants it.
- Stop after excessive bulk: Disable

AC INPUT CONTROL tab settings options: You can setup this up if you have some need to do so.
 
Thanks, Mister Sandals and Q-Dog, my current setting are the default setting. I haven't even fired up the Multi Plus yet or performed the firmware upgrade I was told would probably be necessary. I'm just hoping to determine what settings I might need to change and to what once I get there. My service will be max 50A with a 50A breaker and 6 awg wire between Multi Plus and breaker. So I'm assuming the Charger tab Charge Current setting should be set to 50A.

Thanks, Greg
 
Hello RMADDY, the detailed information you provided is very very much appreciated. I'm still a novice and trying to learn, but I am a bit unsure what absolutely needed to be changed and what shouldn't be changed, and not 100% confident to what many of those settings needed to be. I really appreciate you taking the time and effort to respond so clearly to each of those TABed sections different setting options. This will definitely help me and I'm sure many others too.
Thank you!

Greg
 
You really should read the manual and get a better understanding of what the settings do before you start changing things. Just to make chasing down errors a little bit easier.

This reminds me. I recently added more battery capacity and should increase the battery charge current on my Multi, though it isn't super important since I hardly ever charge from the grid. I probably should reconsider low voltage and SOC shutdown parameters too.

I still don't have as much battery capacity as Greg. (y)
 
I have not hooked up the batteries yet or performed the initial Multi Plus firmware update and related firmware setting changes.
Connecting to the batteries should be a safe and simple thing to start with. When you connect with the app, it will probably ask you if you want to update the firmware (which is completely different than the settings you are asking about).
It will boot up in "auto voltage detect mode" so that it works out of the box without ever being powered up. You should first set the working voltage to 24V instead of auto detect.

Then you can set the battery type. After that, its probably good to go unless you have some particular use that requires customization or if you'd like to change charging to more conservative settings. My experience with a Victron 100/30 was that its charge profile was on the high end of the LiFePO4 voltage range. You should follow your battery manufacturers recommendations, unless you become certain that you know more than they do.
 
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