2 Victron LFP smart Batteries 25,6V 200A with integrated BMS
1 CCGX
1 BMV
ESS activated
The lithium batteries are only charged by the MPPT.
I read that to garanty lithium life time batteries, it is necessary to balance the Cells at least once a month. In my case, leaving in Portugal, it is automatically done by the MPPT once a day as can be seen on the graph below.
If you have the Victron Lithium Smart batteries then exactly which external BMS do you have connected to the batteries.
The Lithium Smart batteries do not have an integrated built in BMS. Victron did sell some batteries with inbuilt BMS that have no comms link to the GX device.
This will affect how the system is integrated and what controls you can adjust. If you are not sure then post a photo.
Inside the battery, there is a BMS which i can access through blue tooth with my phone.
My system is equiped with a BMV and CCGX. I do not know which device is controling the battery. I did not find any place where I modified th 56,8 V except in VE config. I believe that If I do so, the battery will never balance the cells correctly anymore.
The Lithium Smart batteries have a Bluetooth board inside which measures cell voltage, cell temperature and balances the cells BUT it is not a BMS, it does not have any safety shut down systems. These batteries have a pair of 8mm communications cables that should connect to an external BMS that is then connected to the CCGX.
The only Victron BMS giving full control of the chargers is the Lynx BMS, the other ones do not control charging. If you had a Lynx you could set your charging to less frequent bit the other ones leave the MPPTs to do a daily absorption.
You could connect to your MPPTs with VictronConnect and change absorption to fixed rather than adaptive and to 15 minutes. This will then give the approx 8 hours absorption per month recommended in the manual for daily absorption.
I am still worried that you may not have a properly configured system, confirm what battery type you have (battery code or photo).
My battery model is LFP Smart 25,6V x 200A. Effectively, you can see on the photo that there are little black wires which are connected to a small black box with a blue led. This box is also connected to the BMV.
I was told that they battery has inside BMS with protection built in.
I am sending you a summary of the parameters logged into the various equipment. VICTRON with ESS Fallback Tunings.docx (19,6 Ko)
Looking at your document, I have a VE Bus BMS which is installed with the small blue box connected with RJ45 located inside the master inverter.
To access the parameter, I need to open one inverter to connect a MKII box and a PC to run VE config.
You posted your photos while I was writing my reply so I did not see them before hand.
You have the VE Bus BMS, it is the VE Bus BMS that has the safety system built in which shuts down chargers and inverters if there is a battery problem, so you have a complete system.
The VE Bus BMS does not control the MPPT charging though, the MPPT settings control the MPPT charging, so you need to modify those with VctronConnect on your phone using Bluetooth connection. There is no way to go to weekly balancing, the MPPT starts a new charge cycle each day. As I wrote above, the way to minimise time at absorption voltage is to change the MPPT to fixed absorption time and set that to 15 minutes.
Thanks for the feed-back.
Can you confirm where I can find the MPPT “fixed absorption time parameter” I have to modify?
Can I do it in VE config or elsewhere?
Thanks
Use VictronConnect on your phone to connect using Bluetooth. Then go to settings (the cog wheel top right), then choose battery settings, then choose expert mode, in there change absorption duration to fixed and the maximum absorption time to 15 mins.
This is all explained in the manual Section5, here is the English version. If you go to VictronEnergy.com and choose your country you should be able to find it in other languages.
Good morning,
thanks a lot for the detailed explanation.
The MPPT installed in my system are about 10 years old and they do not provide access to the parameters as described into the MPPT doc refered in your message. For example the rotary switch to select the battery type is a physical switch hidden behind the MPPT.
Revisiting the ESS option, I found that in the DVCC part, I have the option “Limit Battery Charge Voltage” . I have been selecting this option and putting 56 Volts. I will see soon wether this parameter will effectively avoid dayly balancing or not.
I will let you know.
Best regards and many thanks
JM
Unfortunately, this parameter with setup at 56 volts does’nt limit the MPPT voltage.
I will cross check the BMV parameters directly on the console.
Have a nice week end.
JM
Hi,
In DVCC, I have logged 55 Volts as the maximum voltage the MPPT can deliver.
here under the graph showing that it has some effect on the balancing, but it does’nt not really block the MPPT voltage and cell balancing is done in multiple steps!
Any idea to resolve this issue?.
That DVCC voltage limit only applies to managed batteries sending CVL to the system. If you don’t have a battery that does that, it is unlikely to help.
Thanks for the comment. This confirms what I have experimented. I have deselected the parameter into DVCC.
Any proposal to avoid balancing the cells every day for 45 mn at 56,6Volts?
