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REC BMS on default settings and Lifepo4 Batteries

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Jakub95

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Hello. I am building a 16x 3.3V 280Ah Lifepo battery bank with REC-BMS connected to Victron Easysolar and GX. Everything is wired up, except I can't connect to the BMS since the wifi module is not detecting the BMS. However the display is working. I asked REC for help and we are figuring out how to make it work.

My question is. Can I leave the system on with the default BMS settings until we sort the connection problem? I believe that the default Chemistry is set to Li-ion instead of Lifepo. Will it damage the system?

Thanks a lot.
 
Jakub95 said:
Hello. I am building a 16x 3.3V 280Ah Lifepo battery bank with REC-BMS connected to Victron Easysolar and GX. Everything is wired up, except I can't connect to the BMS since the wifi module is not detecting the BMS. However the display is working. I asked REC for help and we are figuring out how to make it work.

My question is. Can I leave the system on with the default BMS settings until we sort the connection problem? I believe that the default Chemistry is set to Li-ion instead of Lifepo. Will it damage the system?
Click to expand...

Li-ion BMS typically permits voltages up to 4.2V. Though they are tolerant to that level, it is stressful to the cells, and it's not recommended for LFP.
 
Thank you for your reply @snoobler . Actually I was mistaken, looked into the wrong sheets. The chemistry is LifePo, however the default BMS settings are for 200Ah. Mine are 280Ah cels.

Do you think I can leave them on?

1619188282675.png
 
I have run it for 2 days and noticed that it is not discharging more than 10-11A. I'm going to keep it on and see where it leads. I trust that with the support of REC i will solve the settings issue.
 
Pyrofx said:
Your settings are ok. Mine has been up for 2 months now and flawless
Click to expand...
I left the system on today. We have intermittent weather here in Slovakia. At first BMS reported warning that some cells are out of balance, it was strugling to balance it. Then the whole system went over 60V, red lights on victron and I believe GX lost connection to BMS and started beeping. I have shut down the system, left Victron on OFF and restarted BMS.

This is what the cells look like at the moment:

1619262584250.png

Resistance is now the same for all, until now it was always different for every cell, let's say between 0.4 and 1,2 mOhm.

1619262678447.png

I wonder what have I done wrong, or what component is failing :oops:
 
That resistance is a default. It will always show 2.0 until it loads or charges.
Have you email Time at rec ? He is the head development guy.
It looks like it is not talking to the victron. Mine was also sent with wrong firmware setting . It's charge algorithm was off.
 
Hello @Pyrofx .

Before my resistance was something like this, that's why I am so worried:

1619269318057.png

I am talking to REC but so far I was not able to make the wifi module work with the BMS. The FW update of both Wifi and BMS has not been successful. Unfortunately I do not have the PC Master SW, in order to play with the BMS settings or do an upgrade.

Is it possible to download the PC software from a public URL? I think I've got the RS-485 cable somewhere in my "cable box"
 
By looking at those numbers , I suggest sanding each contact area and putting some dielectric grease on them. Mine also looked lime that until I cleaned the oxidation off the batteries.
I don't know of a public source for software. Since there are such issues , ask Maja to send it to you.
They tout the system as awesome and tell you there are hundreds out there flawless. I don't believe it.

I welded a contractor with my manual overcharge that used same values as theirs. The basicly called me an idiot. I bought 4 of their units , installed them with new contractors. It welded after 3 cycles, no load. Then said can't be our unit , we have lots of them working
 
Thanks for your advice @Pyrofx .

I expect that this is a DIY system and once I saw all the components I already got anxious which one is going to fail first :) On the other hand I am a rookie and my only source of knowledge is youtube and this forum. Since the company that installed my victron and SLA batteries 3 years ago knows about Lifepo4 as much as me 2 months ago :D

I also used U shaped terminals (aliexpress ones) for the BMS to battery + , so perhaps I should look into this as well. I should probably put my old setup back together and wait for REC to resolve my firmware and settings issues.
 
Jakub95 said:
I left the system on today. We have intermittent weather here in Slovakia. At first BMS reported warning that some cells are out of balance, it was strugling to balance it. Then the whole system went over 60V, red lights on victron and I believe GX lost connection to BMS and started beeping. I have shut down the system, left Victron on OFF and restarted BMS.

This is what the cells look like at the moment:

View attachment 46470

Resistance is now the same for all, until now it was always different for every cell, let's say between 0.4 and 1,2 mOhm.

View attachment 46471

I wonder what have I done wrong, or what component is failing :oops:
Click to expand...
if your batteries went over 60 (3.75 per cell)
that is bad
that's is a charging issue not bms (besides it didn't disconnect the charger)
 
Hello @GSXR1000 . I think one or more batteries went over 3,75V and that triggered an alert. I believe that the red flashing overload light on victron meant, that it finally stopped charging. It was the first cycle so the BMS was strugling to balance the battery bank. It was overheating. The REC also says int he manual that that might happen and that in that case you need to restart the BMS.

Anyway since then I disconnected the battery bank. the BMS is not set properly so I want to be 100% it is not because of the battery capacity setting or some other parameter I don't know about.

I am still not able to access the REC BMS settings. REC guys still have not figured out how solve my issue with wifi module and bms not talking to each other. Since I did not order a PC software and was relying on the wifi module only, my system is still off. It is quite frustrating, I've been waiting for the 3rd week now. :-(
 
the BMS doesn't charge the batteries... what is supplying the charge current?
 
I got Victron MultiPlus 48/3000/35-50 and Venus GX, which is connected to Rec BMS and should control the charging.
 
First i know nothing about the rec BMS... I would assume that your victron has charging setting that needs to be set to match your batteries. It sounds like you are saying that the REC should tell the victron to start and stop charging?
 
are you sure you're not suppose to set charge voltage on your victron?
 
That is my understanding. I am quoting REC manual:

Battery Pack’s Charging Algorithm:
The communication between the REC BMS and the Victron CCGX is established through the CAN bus. All the parameters that control the charging/discharging behavior are calculated by the BMS and transmitted to the CCGX unit in every measurement cycle.
The charging current is controlled by the Maximum charging current parameter. It’s calculated as Charge Coefficient CHAC x Battery capacity CAPA. The parameter has an upper limit which is defined as Maximum Charging current per device MAXC x number of inverter devices SISN.
 
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