Setting up a REC BMS, a Cerbo and a Multiplus 2


  • Hi All I am in the process of setting up a lithium batter system on my boat, I have the various bits working. The Mutiplus will charge at 120A but when the Cerbo is connected it is cutting it back to 60A. I have looked through the Cerbo settings, more specifically the REC section in the Cerbo and found the \"Parameters\" section, and the Charge Current Limit is set to 60A and the Discharge Current Limit is set to 75A, but the settings in the REC are 200A for charging and 250A for discharging. What does this mean?? temperature fairly low at the moment?? could it be the Cerbo cutting back?? I have a temp warning at the moment..... or is there a setting that needs changing??? I cant seem to find it if there is........ I would appreciate any help anyone can offer...... Thanks.


  • Check under dvcc, max amp setting.  Post screenshots from this settings.

  • Hi Ben Screen shots as requested. Thanks for any help you can offer🤞🤞🤞👍

  • No \"limit current\" in dvcc, thats good. Other suggestion: check REC app. In settings: is \"amount charger devices\" set at 1? Under the same settings, what is set at total Ah?

  • Hi Ben It’s all set up as you say….. the total Ah is set in the total Ah box. Any other suggestions would be very much appreciated👍👍  

  • I have no other suggestion. If I change the \"max charge current\" I see seconds later in the Cerbo the CCL is changed to the new level. Maybe ask REC. If you solved the problem, please give feedback.

  • Hi Ben Thanks for this I have asked Tine @ REC but I haven’t had a reply yet, when I do I will update this post. Thanks again for your help.

  • Hi all Reply from Tine:- Check the Charge/Discharge algorithm in the Manual. It uses Maximum device charge current setting or capacity x charge coefficient whichever is lower. So I will look at this a when I can get aboard with a PC.  Attached is the section from the manual, hope it helps someone else.

  • How I see it. All settings from this part from the manual are correctly set, see screenshots above. Did you have send the same screenshot with all settings to Tine? Screen shots from REC and from Cerbo: REC/Parameters/cvl,ccc screen.

  • Hi Ben Having checked the E-Mail I had sent Tine, no I didn’t include the REC screenshot…… 😔😔 I have also followed the command instructions and it seems they are correct although it wasn’t quite the output I was expecting. Well done for spotting the figures on the BMS screenshot, I must confess I did think it strange that the BMS knew the battery capacity and that Tine was wanting me to enter it again……. Thanks for your help

    1. Which firmware you are using?
    Did you try another version? Do you use single main relay, or separate charge/load relays?

  • Hi Ben No I haven’t tried any other versions, which ones were you thinking??? I have asked Tine in an e-mail but I haven’t had a response from him yet. It’s a great product and it’s great that the BMS is communicating with the charging source, otherwise the charging source has no idea what is happening with the batteries. It would be nice if we could get it to work as it should……. Thanks again for your help.  

  • Hi Ben This is the reply from Tine:- CAPA is the String capacity and it multiplies the number of strings in case of Master/Slave
    You can set the number of devices with a SISN or STRN for ABMS and then MAXC and MAXD of the devices.”
    But to be honest this doesn’t mean a huge amount to me……
    I have asked him a few more questions.
    Best wishes to all

  • All settings Tine describe are in the screenshots you have posted above. In my view all set correctly.
    • What the commandos means is in the manual.
         

  • Hi all My charging issue has resolved itself, the last e-mail from Tine said that there was also a temperature feed into the charging rate and that the charging rate is reduced to a 1/3rd of the preset value. My charger is now pumping out 100% of its capacity without any issues. I am yet to work out if it’s a “warning” which triggers this or just an alarm due to low temperature, but I am quite happy that it is doing this and looking after my cells. Thanks for your input Ben Best wishes to you all….

  • I have to add to my post above that the default low charging temp is -10 C which seems a bit low as my battery supplier said to not charge below 0 I had changed mine to +5 C, but have since changed it to +3 C with a hysteresis of 2 C. What other temperature settings are other people using and what would be the reason for setting it at -10 C. Best wishes to all

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