Hi Maarten,
I’m getting my cells from Alibaba.
my last order I paid 73 USD for 280Ah new lifepo4 cell.
before that I paid 43 USD for 152AH
Transport to Thailand DDP (all cost, including tax pre-paid) about $ 3,- per kg, for a 280Ah, 5.5kg + packaging = 18 USD per cell
I received reply. from Digikey to pre- program the attiny841
for the first 10 you pay 50 USD
for the next 200 also 50 USD
Outside USA you need to do “CCATS process” During this process, you will go to the government site, upload your program file, and they will assign a ECCN number for your program.
If you choose to ship within the US, we will not need the ECCN number, but please note, if we ship in the US and later you choose to ship internationally, there is a good chance this product or IC will not make it past customs.
If one would need 200 , the price, 50 cents is not that bad.
if you need 8… $ 6.25 is quite high!
Does anyone have any extra assembled boards they would sell? Ive been trying to get an order set up with JLB but running into issues, and I do not have the time or dexterity to assemble myself.
I would be looking for 5-10 cell boards and 1-2 controller boards.
Hi, is there anyone who could show their grafana dashboard of this great diyBMS? Could you post your screenshot and also export your grafana dashboard? It will help me (I am sure that also lots of people) to desing a nice dashboard.
PLease, share your screenshoots and exports your dashboards, THANKS.
In Germany it is not a big issue to find cells and think it is also possible to arrange a delivery from Germany to Belgian. There are many offers on German ebay with laptop batteries, bike batteries and cells itself. I personally started my search there, and then found some dealers that provide me cells directly for 0.30-0.35 Euro for a cell including delivery (usually these are samsungs icr18650-26/28/30, lg lgabc21865, sanyo ur18650zt/zta). And also from a bicycle service center - they sell me e-bike batteries that were intended for recycling, sometimes really good cells could be found there because of bms failure or something similar.
So, since there are no customs for deliveries withing EU, try to find a supplier in other EU country (DE for example). I was sending once a package of tested cells (too low capacity for my project) to Spain, it was fine, the buyer was very happy.
Have a question about debug and wifi rst pins. After short wifi pin my module dont reset wifi settings. I try to flash firmware from release and from platform.io, but wifi settings no reset with this pin. After booting with debug shortened i have many errors in com port at 78k speed and no booting controller. Tell me that i do wrong. All cells modules work great, making good cables is very important
And how your power controller at real battery? From one cell?
The debug pins are a serial port don’t short it out!!
The WiFi reset should be shorted and the controller rebooted, should then go back to ask for WiFi configuration
This is a screenshot of a 3S13P pack i put together today. I have the cell voltages set to 4.12. As you can see both cell 1 and 2 are burning off load to balance the pack.
This is the first part of my 3s80p Battery, which was running the pump of a swimmingpool for the last year. Now I can see, that cell2 is degrading more than the other cells. Cell1 and cell3 are alternately try to ballance. Nice to see it working…
And I am still waiting for the external termperatur sensors from China.
Also I have set alerts to 4.1V for every cell. I get a message to my Telegram Messenger, everytime a cell is over 4.1V.
Anybody has the same problem?
Help! Killed my third cellmodule now!
I installed the BMS on a 3s80p battery with v4 Controller and ready assembled cell modules v4.2. It works fine. Data is sent to InfluxDB and MQTT.
But when I charge the battery with 5 or 10 amps it just takes 15 minutes till one of the cell modules stops sending data and stops blinking - all leds are off. It appears as a cell on the controller website but with 0V. And I cannot reactivate it anymore. I tried to reprogramm it again - no effect. These modules are gone… 
For charging I use the iCharger X6. Charging with 2 ampere has no effect.
thanks. for telegram do you use nodered ?
Only fill in the required data in Grafana.
Just follow these instructions. I think this should still work…
Thank you Stuart for the additional debugging suggestions. I have changed the Controller setting to have 4 banks. That did not seem to help. Elsewhere on this forum, you had suggested an Arduino sketch to erase the EEPROM. I successfully uploaded that to the ATtiny and then reflashed with the latest Hex. Still did not work. Each cell module still flashes green every 8 seconds until I plug it into the Controller.
BTW, I use the following AVRDUDE command to flash using an Arduino Uno:
avrdude.exe" -CC:\Users\trinhl\documents\avrdude.conf -v -pattiny841 -carduino -PCOM3 -b19200 -Uefuse:w:0b11111110:m -Uhfuse:w:0b11010110:m -Ulfuse:w:0b11100010:m -F -e -Uflash:w:“C:\users\trinhl\documents\ATTINY841_Module_Firmware.hex”:i
Just in case there was a problem with flashing using the Arduino, I also successfully flashed each cell module using a USBASP with this AVRDUDE command:
avrdude.exe -CC:\Users\trinhl\documents\avrdude.conf -v -pattiny841 -c usbasp -B16 -Uefuse:w:0b11111110:m -Uhfuse:w:0b11010110:m -Ulfuse:w:0b11100010:m -F -e -Uflash:w:“C:\users\trinhl\documents\ATTINY841_Module_Firmware.hex”:i
Do you see anything wrong with the fuse settings? Could anything be wrong w/ the Controller (WEMOS)? Any troubleshooting suggestion would be greatly appreciated.
Thank you!!
Have you checked the serial leads? Did you buy the JST connectors pre-made or make your own?
I had a similar issue where the JST connector looked fine but wasn’t making contact correctly.
Use platformio to program the latest code instead of using the precompiled one.
I suspect the modules EEPROM has ZERO’ed - if you can see the module from the controller, take a look at its configuration I bet the values are wrong/zeros which is why it reports a 0V reading. It doesn’t flash the LED’s anymore because it thinks its on the wrong bank.
If I short wifi rst pins and power controller it not boot
