I just placed an order for the controller board on jlcpcb that I made. It should be totally compatible with the ESPController, but has:
1 TLC2944, which I will have to solder myself (UGH!). I did not find any > 20v charge counter that was through hole. This will be used for the main state of charge. It will be connected to a shunt and can handle 48v systems.
1 INA226A, which is available in through hole. I would have used another TLC2944, but it has a hard coded i2c address and I figured it wasn’t worth taking additional wemos pins. The INA226 will monitor the PV current and I will need to make a timer to poll this current in order to sum it over time in the wemos. It is not a very critical number, so there isn’t a need for another counter like the 2944. However, this cannot handle more than 36v.
4 opto relays. They are able to handle 400mA of and a bunch of volts. These are 2 in each 8 pin DIP, so easy to solder.
I figure I should be able to modify the software so that it detects the 2 amp chips and takes advantage of them or not. I am a software developer, so that doesn’t worry me too much. I’ve never made a circuit before, so this should be interesting.
I have 3 ESPController boards and some spare “danger hot” boards (not sure what the proper name is). These have the attiny soldered in already from jclpcb.
First off a big thanks for the latest video, not only for having it setup to get them pre-built but also for how to do that process with them.
Everything did look to work properly but they did come back with a question about polarity and I responded with use the polarity in the picture. Heres another big thanks, the gerber files and csv files generate an excellent picture so I was comfortable with my response.
Does it make any sense to silkscreen polarity ? Just looking at the png files from github Im inclined to say no (there just doesnt look to be room), but thought it was worth asking.
Anyone have any thoughts on using one of these to power the controller?
I currently have a 3S15P test pack and I decided to wire one of these direct to the pack to power the controller. I now seem to get a lot of communication errors.
Start with anything you have! Probably 47uF or similar, just make sure the voltage rating is okay (5V+) and ensure you get the polarity correct if its an electrolytic cap. It may be worth also including a low value cap as well - like 100nF.
[Smoothing and Filter Capacitor Calculator - ElectronicBase]
@John_Taves THANK YOU. Tonight I solder! Already have two small 7s packs ready for testing. And @stuart thank you as well for this incredible project. I look forward to the revisions offering more current and more capability.
Hello to all! Those who are experiencing problems in the work of DIY BMS. V3, cross charts and reboot esp. Impact of interference. On the esp, pull up the ‘RST’ and ‘EN’ pins to +3.3V with a 2.2kΩ resistor. On pins 3.3v and ‘EN’ , hang ceramic capacitors at 0.1mF relative to gnd. For fast real-time balancing, change the last line in the esp code from 20,000 to 500 - 1000
//Update Influxdb/emoncms every 20 seconds
next_submit = millis() + 500;
}
Hi @stuart, I would like to know if you want to collaborate with me and make an affordable commercial version that i can sell in South Africa. I have a small startup that lets people do DIY and I’m looking to make it more affordable to get a salable system for People. Let me know if you are instereste.
I should have looked at the cost difference for 30 but didn’t want to hog them all. I’ll have enough for three 7s banks (10 circuits on hand already) which is all I need to get rolling.