Best of the New Year to All,
I have a 3p4s 12v setup on my boat that I thought I had working correctly but something is not right. No fancy Blue stuff here, all old but working just the same. All my charging sources are on the charge bus fed by a Tyco relay and all my load sources on the load bus fed from another Tyco relay. BMSA 2.92-0 and HW 2.1 with WiFi module HW 2.0 SW 1.6.2 and Precharge module 2. What I really need is a hand hold into setting up the relays to provide HVC and LVC. A schematic and programing using tasks or whatever I need. I have wired up using the two relay with precharge schematic but the wrong relay trips so maybe just need some setup. Any help appreciated.
Cheers
The setup you describe is "separated charge and load bus"
You need to install the correct firmware.
download: https://rec-bms-na.com/product-manuals/#7-8-wpfd-rec-active-bms
from the readme file:
2.9.2-1 (one main relay/contactor)
2.9.2-2 (two relay/contactors, with separate OV UV trip functions) For split bus systems only
Suggested settings for relay 1, under task. (Charge bus)
highest cell
negative with off...
value 3.6V
hysteresis 0.1V
suggested other settings:
balance END V 3.52
balance START V 3.45
MAX allowed cell V difference 0.25
END of Charging V 3.52
END off charging V hysteresis 0.17
MAX allowed cell V 3.65
MAX allowed cell V hysteresis 0.25
MIN allowed cell V 2.8
MIN allowed cell V hysteresis 0.1
MIN cell V discharge (inverter CAN) 2.9
Charge float voltage Coefficient 1
SOCH end off charge hysteresis (0,05=5%) 0.05
All settings are personal choice, like how to charge your batteries.
@Ben Thanks for getting back to me. I do have 2.9.2-2 loaded. Tried to edit my earlier post but couldn't get it. I'll try your settings and look at that manual for a start. Should everything be wired like the diagram on pg7? Also it shows contactor 2 so how do I program that one?
Cheers
@Ronald There are different manuals, I don't know what your pag 7 shows.
About the settings from previous post.
Under task the settings are for charge relay, use cable marked with CH. Under task named relay1.
The other settings I mention is for the other relay.
@Ben Page 7 of the manual you linked above. For the other relay, is that the opto in tasks?
@Ronald the opto are other outputs, see manual.
@BenOkay, wired per this diagram and settings as per your task-relay1 (charge relay), when I test for LVC the charge relay trips open instead of what I thought should be the load relay. Not sure if technically correct but the way I tested was to raise the min cell voltage in settings just above the current value to trigger a shut down. 
@Ronald For me is not clear which minimum voltage you change in your test.
If you did this in Task under relay1, then you are programming relay1, as a "low voltage" shut down.
Not what you want, I expect.
With the suggested settings, you can test the behaviour from relay ChargeBus, relay 1 under task.
Program a settings that is below the current cell voltage, the relay will go off.
In the setting tab(not under task) you can make a fake setting, "MIN allowed cell voltage" that is higher as the actual cell voltage.
Your load contactor will switch off.
Hi Ben,
When I go into tasks to relay 1 set to highest cell - negative to off, and put a lower voltage in than present, it does trip the charge relay and leave the load relay connected. Good! When I go into settings and change the lowest cell voltage to a value above the current cell value, it trips the charge relay too and the load relay remains latched. Not good!
Your thoughts?
I did a test.
Installed a fresh downloaded firmware.
Made the suggested settings.
All worked. (I use a test setup, with 4 LED to monitor all outputs)
Advise, double check firmware version.
After press update, the file is loaded. You get a first messages, do nothing, wait at least a few minutes, another message will come, ask you to switch off and on the BMS. Wait again a few minutes, BMS restart and start working again.
And double check your wiring.
I wonder if there is an issue with the module 2 precharge unit. The 6 pin descriptions are different than the newer 10 pin and possibly (probably) miswired in some way. In particular mine says BMS input + and the newer module 3 is BMS -. Of note, when I shut the BMS down via the little switch, it unlatches the charge relay but the liad remains connected. When I went into settings and increased the voltage setting for min voltage above current cell coltage, the BMS red light and alarm would sound but no load relay disconnect.
