After a battle to get the comms between a B4850 battery bank (master and slave) - my mate and I have had to select the USE mode to keep the inverter from shutting down prematurely which it does with PYL selected in menu 5. The inverter now seamlessly does changeovers from mains to battery but again in Use mode - the low DC cutoff will not adjust below 48V. The manual states this value is by default at 42V which is not the case. 
What are we doing wrong? 

Edited August 18, 20223 yr by VaughanT
Title incorrect

Hi there Vaughn

I have the Mecer MKS IV - with Dyness B51100 battery.

Also had initial problems getting the battery to comm with the inverter - I had another issue which I had to send the unit back to Mustek and upon return the BMS and inverter can now comms.  I believe the ciruit board that they changed may have a later firmware.

In terms of your BMS cable

Confirm that your cable has these pinouts or make one:

This is the cable for the Dyness B3 but I think your battery will be the same.

 

Also go check out SolarAssistant: https://www.solar-assistant.io

and MultiSibControl: http://www.multisibcontrol.net/

With both of those you can manage your inverter and battery bank.

EDIT: Use these values for USR settings:

Edited August 23, 20223 yr by Douw Gerber

Also try your jumpers as follows:

0100

1000

0010