As a chemist who loves electro-chemistry, battery technology has always seemed incredibly interesting, especially since it’s within the group of potential topics that could be researched with some degree of success at home. This is because batteries can be made within a very wide array of chemistries, some of which use very easy-to-find materials and the equipment necessary to research batteries at a small scale should not be hard to build.
However, after looking at a lot of people sharing their DIY batteries at their own houses on the internet, it seems clear that most of them don’t do any proper characterization of their batteries at all and those who do – who appear to be very few – seem to use relatively expensive pieces of equipment to do so, probably the lower end of what would be used within a regular university research environment.
The options available to minimally characterize batteries, which means at least measuring their charge/discharge curves seem to all be expensive and there is no commercial option I could find that would allow you to perform these tests for less than 1000 USD.
However, I did find a very interesting publication (here) where the researchers share the PCB, software, firmware and bill of materials for a cheap galvanostat/potentiostat that can be used for the characterization of small batteries. Given its limited current +/25mA, it cannot be used for the characterization of any larger batteries, but it should allow for some very interesting and well-done research of small batteries at home.
I added this PCB to OshaPark (you can order it here) and I have ordered the materials from Digikey using the bill of materials provided by the author within the paper (you can use this file to upload to dikigey directly) . The microcontroller used within this project also requires to be programmed using a PicKit3, so you will need to get one here. Note that due to COVID related supply constraints I had to order the MCP3550-50E/SN microchip from microchipdirect.com instead of digikey and I also changed the mini-USB port for a micro-USB port (609-4053-1-ND).
As backup plan I have also ordered a fully assembled PCB board from pcbway.com, which charged me a total of 154 USD for the entire production of the PCB and mounting all the surface components. This is all done in China and the exported to the US, so it will take around a month for the entire process to go through. I want to compare the quality of my own assembly with the product I obtain from China.
In this process I also got quotes for several different US manufacturers for the production of these boards, but came to the conclusion that it is not economical unless I wanted to get at least 10-20 manufactured. This is because the price is often in the 1200-1500 USD range, independently of whether I get 1 or 10-12 boards done.
I still haven’t received everything I need from oshpark and digikey to assemble the board but once I do I will update you on my progress building/programming/testing this open source galvanostat/potentiostat.