Hello from Braunschweig, Germany

Hi all,

just a few words to introduce myself: My name is Oliver, I live somewhere in the middle of Germany and I'm working on my solar powered home for about 1 year now. What I have achieved so far:
+ ~3KWp with a mix of about 30 mono- and polycristalline modules
+ 940Ah battery capacity (8 lead-acid solar batteries)
+ 2 solar chargers, max. 50A
+ 3000W converter with automatic battery/grid switching
+ self-made data logging (arduino to mySQL database, web-interface, DIY mobile display with ESP8266)
+ reduced my power bill for about 500 compared to last year :mrgreen:
(will add some pics later)

Since a few weeks, I'm collecting laptop batteries, harvesting cells and watching videos ;-) Thanks a lot for yours, Pete, very interesting, I learned a lot And also a great idea to open this board So, I just started my diy powerwall project and hopefully will have time to share my experiences.

Have sun
Oliver

Welcome to the group. Im sure there are going to be some people interested in your DIY logging setup. So if your willing to inform, we shall listen.

I'm certainly interested in arduino. I am a complete newbi but the want to learn is there.

It's impossible for me to see all the projects here, but man do I miss some good ones.. your avatar interests me

care to share the arduino hardware and code?

hbpowerwall said:

It's impossible for me to see all the projects here, but man do I miss some good ones.. your avatar interests me

Click to expand...

this intro is quite old, after that, I was very busy, made some progress and added a new thread with pictures here. Just check it out

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JeremyChoy said:

care to share the arduino hardware and code?

Click to expand...

I blew up my data logger a few weeks ago and will completely re-design it... For now, I can give you a short closeup on what I did so far:

I hacked the display port of my charge controllers (EPSolar MPPT Tracers) and connected them to an arduino the get the values for battery voltage, charge currents, SOC and temperatures (of the chargers, not the batteries). the arduino also has a network module connected in order to (1) request the values of my smart meter from my provider (grid ) and (2) save all values in a database on a hosted server. this was done every 10 seconds until I blew it up on March, 27th. Since then, there're no new values saved.

On the server, I have two web pages, one showing a live view of all values, including PV voltage, PV current, battery voltage, charge current, SOC, production of day, current grid consumption and overall grid consumption for the day. The second page shows a graph with SOC, single charge current of both charge controllers, overall charging current and grid consumption.

Here're two pics of the web pages (sorry, everything in german, but you'll get the picture):






I also fiddled a small mobile device together (no, this is not the new iPhone 8 ), which shows me the live values and some sum-ups on a touchscreen whereever I go (works with an ESP-8266 and WiFi):










But as I said, I blew it up and since a few weeks, there're no new values saved anymore. And I made some changes to my solar system since then (added a new panel string and one more charge controller) and want to integrate some more data like currents at different points (charging, battery overall, lead-acid bank, 18650 bank, inverter), temperatures of my powerwall (working on a multiplexer board that will be able to control up to 70 temperature sensors) and series voltages of my 7s 18650 powerwall (no solution for this, yet). So, I won't be able to present a working solution very soon... and I also doubt if my solution will be easily adoptable by others.

But if you have any questions or need help, feel free to ask .

Have sun!
Oliver

Great solution. my plan is to create a completely separate system so your solution doesn't help me
ESP32 with DS18B20's, and reading 14s voltages. will send that data over wireless to a server which will parse the data to a dashboard/send warnings

JeremyChoy said:

Great solution. my plan is to create a completely separate system so your solution doesn't help me
ESP32 with DS18B20's, and reading 14s voltages. will send that data over wireless to a server which will parse the data to a dashboard/send warnings

Click to expand...

sounds interesting... do you already have an idea how to read 14s voltages?