Firstly, Welcome to my project thread, where I will be documenting my Long (And very slow) progress through to building a powerwall Incrementally in values up to around 10-20Kwh.
I am starting from literally no experience in this, apart from watching all 172 videos from Peeete
I have a lot of enthusiasm, not a lot of money, and a few skills I will be throwing in the mix as the project develops into what I hope to be a really good end product, using a data driven approach. The more data I collate the better. As a professional software developer, im sure my skills will be improved by using them in different ways as well.
Will soon be showing the projess in the form of pictures and screen shots, got my initial 50 cells here to work with and map and develop the software over christmas to ensure we get a good end product. once I have firm designs it is my intention to release all hardware designs/software on a free for non-commercial license.
So now onto the project goals.
1. Build a power generation/storage facility that can negate the power usage of my business ~10kwh per day.
2. Put in place systems to evaluate and monitor individual 18650 cells, providing discharge curves, ESR, Initial voltage when recovered, Voltage at each top up charge.
3. Ensure that batteries are always operated within there safe limits
4. Minimise the amount of labour required in testing cells/gathering cell data.
Onto Point 4, I have already built a arduino based charger/discharger which charges at 500mah via a tp4056 and then discharges a single cell using two resitors. Providing the data over the USB lead. This has severe limitiations in the fact that it will only work on a single cell, and the charge limit is very low due to the fact it is charged over USB. Therefore I am upgrading this design to utilise a ATX PSU, which can provide 49 Amps via the 5V/12V lines and convert them both to a single 5A line running 30 Amps, which will be used to charge 30 Cells at once.
Once charged, the system then switches to discharge mode and outputs the data over serial, currently into a terminal program, but this will be altered to use a C based program which will log it to a MySQL database, from where I can produce graphs, each cell will be checked for power consumption ever 1 second. giving a good scope of data of how the cell is operated.