Yet another BMS
- Thread starter smartbms
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fpie
1 mW
zhivko said:
Hi,
No, this chip is not the right one to build a 24S BMS. You should prefer an ISL94212 but no protection neither current measurement on that kind of IC.
Linear is one of the first to develop that kind of 12S stackable ic : LT680x family. Plus, Linear never obsolete any IC, on the other hand, price is high.
I think Maxim IC and maybe some other manufacturers have also its own solution but with the same philosophy, stackable, but only monitoring and cell balancing, no protection and current counting.
What chemistry and capacity/current do you want to hold with your BMS ?
dmwahl
10 kW
DIY people are not really the target market for those chips. TI, LTC, Intersil, etc aren't going to worry too much about one-off designs as there's no real volume. Anything with enough volume for them to care about will be a fixed solution.circuit said:
fpie
1 mW
I agree with you. Hobbyist electronics with highly specialized ICs is quite hard, from purchasing to soldering...dmwahl said:
About ISL94203, it seems that someone have ordered ten of on Mouser website. As a consequence, a stock of 990 is forecast for the beginning of June.
fpie
1 mW
Somebody there contact me these days to share some experience with ISL94203 ic.
So, it make make me a comeback into this project and the idea that somebody else will suffer as i did into datasheets, code and so on make me want to help him (and probably help me to feel this project "alive").
To remain in peace with my mind, somebody else there contact me a year ago, i ask about thinks i never did. No time, i apologize for this.
So, the design is under eagle (not kicad, but next time for sure) and respect the usage of a no commercial design (less than 100x80mm board, one sheet of schematics). You can then download and run a fresh installation of eagle and go into design :
http://www.cadsoftusa.com/download-eagle/
View attachment 8S_SMART_BMS.zip
I'll also disclose the fw in some time, but i have to review and release it as a stable version and in a way that help collaborate (Github probably).
...
So, it make make me a comeback into this project and the idea that somebody else will suffer as i did into datasheets, code and so on make me want to help him (and probably help me to feel this project "alive").
To remain in peace with my mind, somebody else there contact me a year ago, i ask about thinks i never did. No time, i apologize for this.
So, the design is under eagle (not kicad, but next time for sure) and respect the usage of a no commercial design (less than 100x80mm board, one sheet of schematics). You can then download and run a fresh installation of eagle and go into design :
http://www.cadsoftusa.com/download-eagle/
View attachment 8S_SMART_BMS.zip
I'll also disclose the fw in some time, but i have to review and release it as a stable version and in a way that help collaborate (Github probably).
...
fpie
1 mW
Let say IDLE. I much more work on pollution sensors by now.
But if you need something, you can ask me.
But if you need something, you can ask me.
Hello Fpie,
I'm working on ISL94202/3 with stm32, just like you. But I had an issue about I2C side of sw. I try to find someone like tried and succeeded communication, and I encounter this topic.
Will you share your sw? Maybe not whole code but communication side of stm32 ?
I hope , you still read this topic
MCO
I'm working on ISL94202/3 with stm32, just like you. But I had an issue about I2C side of sw. I try to find someone like tried and succeeded communication, and I encounter this topic.
Will you share your sw? Maybe not whole code but communication side of stm32 ?
I hope , you still read this topic
MCO
Hello Casainho,
for this time being, my code is imported version of my previous BMS project which includes Bq76930. So, in the code, there is no more than I2C with DMA.
First thing first, I tried to get responce from ISL94202, but always I get that communication timeout.
what will be your help about topic? Pseudo code of comm. flow or sample code of stm32 or ?
MCO
for this time being, my code is imported version of my previous BMS project which includes Bq76930. So, in the code, there is no more than I2C with DMA.
First thing first, I tried to get responce from ISL94202, but always I get that communication timeout.
what will be your help about topic? Pseudo code of comm. flow or sample code of stm32 or ?
MCO
Hi,
I'm working on a project and i'm using a ISL94203. I've one board to test made by me but i can't get it to work properly.
I can read the register of ISL94203 through I2C as the temperature, cell voltage, VBATT voltage...
My problem is with charging the battery, I connect the charger on circuit and the ISL94203 not recognize him and she not turn on the charge FET. I'm using the single path and in both monitor pins (CHMON and LDMON) have voltage of the charger.
My circuit is very similar to yours, Can you help me?
I'm in doubt if the problem it's in hardware or in software. Can you say me what setting did you use?
I'm working on a project and i'm using a ISL94203. I've one board to test made by me but i can't get it to work properly.
I can read the register of ISL94203 through I2C as the temperature, cell voltage, VBATT voltage...
My problem is with charging the battery, I connect the charger on circuit and the ISL94203 not recognize him and she not turn on the charge FET. I'm using the single path and in both monitor pins (CHMON and LDMON) have voltage of the charger.
My circuit is very similar to yours, Can you help me?
I'm in doubt if the problem it's in hardware or in software. Can you say me what setting did you use?
fpie
1 mW
Hi,
It's hard for me to remember all the behaviour of the ISL94203. I do not work on this project since a long time. Do you have the hand on the firmware and your external MCU. One thing to do maybe to read out all registers on ISL94203 and analyse it
Let me know.
It's hard for me to remember all the behaviour of the ISL94203. I do not work on this project since a long time. Do you have the hand on the firmware and your external MCU. One thing to do maybe to read out all registers on ISL94203 and analyse it
Let me know.
This problem it's solve. I hasn't connect the pin FETSOFF to MCU.fpie said:
However I have problem writing to the EEPROM.
I can read RAM and ROM and the values it's correct also I can write in RAM.
Sometimes I can write in ROM but it's very random. I'm using STM32 and HAL library but I also tested with arduino and it's the same.
is it normal have disconnect the battery to save values in ROM?
dmwahl
10 kW
No, there's a process to write to ROM detailed in one of the app notes. I forget the details but as I recall it's basically the following steps with a wait between them to allow it to actually do the write.rprb said:
1) Enable EEPROM access
2) Write the byte to EEPROM twice
3) Disable EEPROM access
4) Compare RAM with EEPROM contents to verify that the write was sucessful
dmwahl said:
Yes I'm making this process but i go try write de byte to eeprom twice.
To read the EEPROM values am I make this same process? Because I can't read EEPROM values with enable EEPROM access.
In datasheet it say that EEPROM values are copied to RAM in power up, "When the device powers up, the ISL94203 transfers the contents
of the configuration EEPROM memory areas to RAM", so I ask if I've to disconnect the battery to save the values and I suppose that EEPROM values that I read are the ones saved in RAM.
Here is the code using STM32f401
https://github.com/rprb93/BMS94203.git
dmwahl
10 kW
Did you have to duplicate the read process? I haven't had any issues reading from the ROM with only a single write. I have a 1ms wait between sending the address byte to read and doing the actual read since the datasheet says it takes ~200us to read from ROM, but I didn't need to do the read twice. Either way it's not a big deal since you rarely need to read from ROM.
derekisastro
100 µW
- Joined
- Feb 28, 2019
- Messages
- 7
circuit said:
I know this is an old thread but I just 'discovered' the ISL94203 and 202 ... yet you say other chips make these obsolete ... what is the best current IC to begin with for a BMS ... 6s-14s as an example?
derekisastro
100 µW
- Joined
- Feb 28, 2019
- Messages
- 7
rprb said:it's working
I duplicated the read and write process and wait 30ms between operation and it's working.
thank
Hi,
How is your project going? I have just found this thread and am interested in how your DIY BMS is going?
I'm relatively new to electronics but I'm keen to learn and make a BMS. Do you have any open source files, etc?
Cheers.
LOL, I see I have answered without checking the content of this thread, as I also follow other topic with similar title.
Sorry, can't comment on this one. It looks dead like every other DIY/open BMS project out there. BMS is actually much more complex thing than it looks from first impression, reason why most don't survive the time.
Sorry, can't comment on this one. It looks dead like every other DIY/open BMS project out there. BMS is actually much more complex thing than it looks from first impression, reason why most don't survive the time.
@circuit.
Actually, I've been looking at the on you kinked to and it looks interesting and pretty well documented.
But ordering it is just so expensive (45€ for shipping to France) !
They have a precharge ability. Have you any idea why they don't use a "hot-swap controler". They could combine both, power MOSFET on the same Precharger Mosfet.
Do you know if they would have some kind of open version ? On what chip it is based ..... ?
It seems you have been quite involved in that TinyBMS. Would you share back some information ?
I can't find any user feedback here or somewhere else. Would you have some ?
I'm thinking to get one of these Chinese SmartBMS that look pretty configurable with BT app plus LCD screen available for about 1/3 the price of the tinyMBS s516.
Would you have any advices to be aware of for the choice ?
Actually, I've been looking at the on you kinked to and it looks interesting and pretty well documented.
But ordering it is just so expensive (45€ for shipping to France) !
They have a precharge ability. Have you any idea why they don't use a "hot-swap controler". They could combine both, power MOSFET on the same Precharger Mosfet.
Do you know if they would have some kind of open version ? On what chip it is based ..... ?
It seems you have been quite involved in that TinyBMS. Would you share back some information ?
I can't find any user feedback here or somewhere else. Would you have some ?
I'm thinking to get one of these Chinese SmartBMS that look pretty configurable with BT app plus LCD screen available for about 1/3 the price of the tinyMBS s516.
Would you have any advices to be aware of for the choice ?