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Potentially yes

14A (0.05C) for one 280Ah is just fine. Lower cutoff current can end up in overcharging, pls read (not only valid in marine settings): https://nordkyndesign.com/charging-marine-lithium-battery-banks/

The SI does what the internal CCCV algorithm of SI is telling the SI to do. The BMS is just telling the upper limit to the SI AND you still do not know what the limit is because SI is not telling you what it receives as limit from the BMS (that what you have to look for). Regarding device, it...

Are you sure. Just repeat myself over and over, you can not be sure if the BMS is tapering the current or your chargers without knowing the actual current limit your chargers are using. That information is still missing using SI. Regarding number of devices, thats the parameter SISN within your...

REC, at least with firmware 2.7 and 2.8 and in Victron Systems sends a 0,1V higher charge voltage limit as the requiered end of charge voltage. If this is also true for the MurphyGuy is unknown because missing SMA monitoring capabilities. An external shunt is mandatory part of a REC Setup.

You have to ask other SMA users or read the SMA manuals how to do that.

Again, if you do not check which charge voltage and charge current limits are sent from the REC-BMS to the SI, it is still just a wild guess if the BMS is defect or not. Eg the charge voltage limit should be a little bit higher as the cell end of charge multiplied by the number of cells, so the...

The BMS can not control the charger, no BMS can do that. BMS is just sending the limits, within the charger works on its own. You have to check which limit the BMS is sending to the charger and when (and you have to know how to do that in a SMA system because you are operating it). For the...

Yes, the BMS tells the SI only the allowed maximum. But at the end of the charge curve the SI switches from constant current ( 120amps in your case) to constant voltage, and the SI is ramping down the charge current and not the BMS (the BMS is just sending/updating the maximum charge current)...

I do not think that the BMS is ramping down anything (or the SI is reacting on that), pls see the quoted section and the linked document. Pls check the charging setting in your SI. It is not a BMS issue.

I found the following section in this document https://us.v-cdn.net/6034073/uploads/CCWTW0ZAVBMU/sma-can-protocol.pdf Battery charging current limitation: This is solely the limit for the charging current sent to Sunny Island. It is not to be understood as a set-point as the available charging...

Just to be sure, have you established the CAN communication between the REC-BMS any our SMA?

I am using REC-BMS together with Victron DVCC and can definitly confirm that it only starts to ramp down the charge current when the first cell hits the end of charge voltage. Are you sure that the BMS tells the chargers to reduce the charge current and there is no internal charge control of...

Set balance voltage end to the same value als end of charging. Balance voltage end is missleading, because the rec is "balancing" any cell regardless of the charge current above this value. So you are blocking your cells from reaching the end of charge voltage. Balancing Voltage END(BALV): If...

Hi all, i am using four rec q bms 16s with a master unit for my 16s4p LFP battery. Since the installation, the cell impedance measurement is not working, showing the same value for each an every cell (0,750mOhm). Therefore the balance algorithm is not working well, as it handles every cell...