iomagico said:
I am looking for a smart and programmable cell monitoring system to activate external relais when over or under cell voltage occur.
No need any balancing system inside the system, just driving cut off for external contactors.
Any suggest?
My SBMS0 should do everything that you want.
It has individual cell monitoring 3s up to 8s it even has build in cell balancing but if you want you can disable that from user menu (not sure why you want to do that but it is an option).
It is fully programmable trough is build in interface so you can set high, low limits for any type of cells along with 30 other battery related parameters.
There are separate outputs for undevoltage and overvoltage but you will not normally use contactors for that.
In case of inverters you just connect that signal to the inverter remote ON/OFF that is typically just two wires in parallel with the mechanical ON/OFF switch and that is switching just battery voltage level and no more tan 10 to 20mA that will be driven directly by the optoisolator integrated in SBMS0.
So inverter will be default on off position and then the EXT IO3 from SBMS0(set as type 2 meaning it will be close circuit if all is OK and all cells above minimum voltage and open circuit is any of the cells are below that limit) will be connected to the inverter remote port.
So not only nothing like a contactor is needed but it will also work. A contactor, SSR or any sort of switch and not be connected between a highly capacitiveload as the inverter is and a battery that provides almost infinite current as switch will get damaged.
The SBMS0 will be available in May currently I run a Kickstarter and will cost 159CAD that is about 120USD
On top of the BMS it also has an advanced energy monitor that calculates the SOC and measures and calculates energy displayed in a graphical format. It will also store internally the last year of data (2 minutes interval) and can be downloaded over serial to a computer. The serial port can also be used to monitor all the data available including SOC, all cell voltages, battery current and battery temperature if you wan to use a battery temperature sensor.
SBMS0 is fully open source and source for this model will be available in May the SBMS40 and SBMS120 source can be found on the last page of the user manualhttp://electrodacus.com/SBMS120/manual/SBMSmanual.pdf
So how is this working out?