@stuart, does the controller board needs external power supply?
Or just the USB for the Wemos?
No, the USB should be fine, as long as its 5V 2Amp rated - a lot of power supplies are only 1Amp.
Hey guys, i am really new to Building battery packs and Recycling old 18650 batteries. I have stumpeled Across this in search for an bms for my next year Outdoor project. I want to Build a very small pack just 7 in Series to get something like around 24V with 2200mAh.
The question i have is if i can Monitor this with just 1 pcb or do i Need 1 pcb for Every battery in Series?
You need one PCB module for every cell in series, and a single controller PCB.
The forum shop sells almost full assembled boards + parts for a reasonable price.
hi @stuart
This trermistor still good for monitoring cell temperature in board 4.21 ?
Thermistor, NTC, 10 kohm, B57891M Series, 3950 K, Through Hole, Radial Leaded
No it needs to be 47k NTC thermistor.
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Been lurking here for awhile and must say this is one nice project. Thank you Stuart for sharing your hard work. I found the diybms while searching for a suitable bms for LiFePO4 batteries. Once you released the jlc files I decided to give it a try.
I’ve run into a couple of problems I’ve been able to solve myself but I have one that has me stumped.
PCF8574 is NOT connected/fitted.
I’ve search the project log and have been unable to correct this. What I tried was changing the address in the main.cpp file per your response to someone else having the same issue. This did not help.
Soldering has been checked and all files compile correctly. I do have another main controller board I’ll try once the 8 pin headers come in. Maybe just a bad chip? Is there anything else I should look at to solve this problem?
Hey guys,
Has anyone else had trouble connecting the ESP8266 Wemos D1 Module to the wifi for their home computer. For some reason I can get the thing to light up, my computer can see it; but I cannot get internet to it.
Using the D1Mini (not pro) module.
Thx.
Hey Everyone,
So I have been running the DIYBMS on a 2P7S 1650 powerwall for the past 2-3months and I am still having some issues with the shunt trip being tripped randomly.
@stuart
- Is there a delay configured in the code before a trip is initiated, something to the effect that if the rule is met ( especially the voltage and temp rule ) that the rule has to be met for a min 5s before the relay is activated, My thinking is that maybe the BMS is getting random abnormal readings and tripping the shut.
- When the BMS looses wifi is it resetting or something, it would seem that these shunt trips are more prominent when we have wifi or internet issue.
- If it is a simple high to low on the PFC chip then can someone help me with a circuit or resistor of sorts that will require the 5v to the relay be active for at least 3s before the relay is tripled to try stop or eliminate these high low signals. Something that needs to build up and drains once on more current is applied.
I recently change from using the Powerwall a purely backup to now running my essential load off grid, and these trips are painful as it trip at random times and them all our essential load go off until someone goes to the Powershed and resets it.
hi @rolfbartels, are you using the latest GITHUB code with the changes to the relay code (if you look at the web interface it should have both Trigger value and Reset value in the Rules page).
The rules are calculated about every 4 or 5 seconds.
We’ve seen poor quality WEMOS clone boards rebooting when wifi goes missing - either an under spec’ed regulator on the WEMOS or a power supply not able to delivery 2A @5V.
Thanks I will take a look at that,
If the @stuarts advice does not help, then a simple delay is implemented through a capacitor and a high impedance resistor.
Hey Daemon, this is cool can you explain and maybe give me the 2 components needed, appreciate it thanks
Hi Stuart,
What do the Reset values do? Have applied this new code and it sorted my MQTT issues - thanks.
-Deon
If it is absolutely correct, then as in the complete circuit, but only 2 resistors and 1 capacitor are possible. ( 5k, 470u, 100 k)
They implement a high and low cut off values, which stops the relays clicking on and off quickly.