rolf_w wrote:the 'bleeder' LEDs are very helpful. did you solder them manually? tricky job...
rolf_w wrote:ecitypower told me to remove CF13 to CF0 if cells are not connected and they did send me 0Ohm resistors as a replacement in case I would want to reuse these inputs again. i did ask for the reason but did not get an anwer yet. According to me this excercise could only make sense if the unused CFs are replaced with 0Ohm resistors in order to shorten/bridge the voltage sensing inputs of the unused cell positions...
rolf_w wrote:I also tried to figure out the current sensing circuit ; the 2 resistors are definitely not the shunt resistors ; i guess the circuit uses the Rdson of the power FET as a shunt to measure the current...
rolf_w wrote:what approach you have to build the i2c to usb interface? I will isolate the i2c bus of each board with an ADUM 1250 , link them all (currently only 2) to the same i2c bus connected to a PIC with integrated CANbus adapter...
...For me with the schematic it's clear: the unused inputs should not be unconnected. So CFx is a capacitor if the input is used and a shunt if unused.
...My boards are a little bit different from you: the CF0 and CF13 capacitors have been replaced by 0ohm resistors
...And I think I/we will have a problem with this: as no curent will pass via the BMS it will enter in idle or sleep mode... will it go to normal mode in case of under/over voltage ?
I think It's just because the wiring to the battery is a little bit simpler, there is no need to connect the unused inputs to the last cell.rolf_w wrote:So we are of the same opinion: if cell#x is not connected use CFx otherwise replace with 0R? Why not just short the unused input pins BCx?...For me with the schematic it's clear: the unused inputs should not be unconnected. So CFx is a capacitor if the input is used and a shunt if unused.
Yes !rolf_w wrote:Did I understand you correctly: you received a bms preconfigured for a 12s pack thus CF13 was shorted as well as CF0 with 0R?
OK nice !rolf_w wrote:I presume charge/discharge event means a certain minimum voltage across the current sens terminals (SRN and SRP). If this is missing the OZ890 goes to idle mode and returns to normal mode according to the above conditions. However, I don't see a problem yet to stack two or more of the bms ...
I will have to scratch my head for a long momentrolf_w wrote:Here is a sketch of a quick reverse engineering job of the current sensing circuit in the SmartBMS. I do neither know if I got the components correct nor if the circuit is right and above all I have not much of a clue what this circuit should do - anybody else can guess?
This parallel to I2C converter doesn't work...
I will try to use a PIC.
no bleeding, even with cells at 4.5V.
Sometimes, with cells at around 3.65v (the voltage I required), the bleeding is enabled.
The number of cells that bleed varies
Do the bleeding is based on the voltage difference between cells and not only the cell voltage ?
romelec wrote:Know I can read the operation registers (i've not yet tryed to write)
..., and it appears that the configuration already had the bleed in idle mode activated...
I've seen that the bleeding is deactivated in over voltage error, so if the over voltage value is set just a little bit higher than the bleeding voltage it can explain the behaviour I have: bleeding is only active for a very low voltage range, let's say between 3.6 and 3.65v.
rolf_w wrote:romelec wrote:Know I can read the operation registers (i've not yet tryed to write)
great! how did you do it? no chance to use the cowboy software? it is quite handy.
rolf_w wrote:I've seen that the bleeding is deactivated in over voltage error, so if the over voltage value is set just a little bit higher than the bleeding voltage it can explain the behaviour I have: bleeding is only active for a very low voltage range, let's say between 3.6 and 3.65v.
have you seen this in the DS or by experimenting? I wonder why bleeding should be disabled during OV
romelec wrote:Well, finally I decided to buy an Aardvark USB/ I2C converter...
gip_mad wrote:Here's the datasheet. Password is wizardofoz
Anyway I need your help, no way to found the OZ890 datasheet. When I download the attached file from grip_mad, the file seems corrup, of course using the password. Can anyone send me this datasheet (uncompressed)?.
you replaced the FET on the high side SmartBMS with resistors?us__007 wrote:I do cascading 2 SmartBMS. Charge and discharge switches allow you to turn it on 100V. I replaced two of the transistor in the circuit current shunt 100 volt.
please explain furtherus__007 wrote:Conclusion SCRL chip zener protected at 58B. in the chain of the legs of the resistor R31 replaced with a face value of 2k 30k.
you followed the AN#16 from O2Micro? 'EFETC-Out' on high side SmartBMS > optocoupler > 'EFETC-In' on the low side SmartBMS ?us__007 wrote:EFETC connected to the output optocoupler, the leg is configured to turn off the charge.
looks like an interresting and busy site - what about this 'monitoring configurator' program - is it made for the OZ?us__007 wrote:Thanks to a colleague Mevial http://electrotransport.ru site for the monitoring program, the configurator and advice.