Flow Battery Research Collective

How did you know the system needed rebalancing? Was there a BMS that informed you or did you realize it yourself? And what procedure did you follow for rebalancing?

(started a new thread here for @azavatone : https://fbrc.nodebb.com/topic/73/azavatone-s-rfb-discussion)

Starting a new thread away from the new member thread!

@AZavatone welcome ! very interested in real field experience with RFBs, you're welcome to share as much as you like! the manufacturer/supplier of the RFB did not include a system/service plan for rebalancing?

Hi all,

Been working on some upgrades to the dev kit for a bit, the draft documentation is out---rough around the edges but all the files are there for fabrication. The cell can now close with a simple C-clamp which is much more ergonomic and resistant to leaks. Most of the parts are forward-compatible.

https://codeberg.org/FBRC/RFB-dev-kit

https://fbrc.codeberg.page/rfb-dev-kit/

Time-stamping the electrolyte formulation for Zn-I, I am making the documentation to build the dev kit chemistry agnostic (so I am taking these weights out of the docs for now)

zinc chloride - 1.36 grams
potassium iodide - 3.32 grams
ammonium chloride - 1.07 grams
deionized water - 8.50 grams
triethylene glycol - 0.55 grams

This usually ends up preparing around 11 mL of solution which we split evenly between the two reservoirs.

welcome @martinr and @jpengineering ! Iron hybrid RFBs are very appealing but managing hydrogen evolution is the real challenge---we've been working on some promising approaches here, Daniel has done some tests on a non-conventional iron electrolyte here: https://fbrc.nodebb.com/topic/44/only-fe-system.

I haven't seen Nighthawk's carbon felt video, but @rowow came through the forum already talking about his membranes! I'd like to get my hands on some to try (don't have the time right now to go into DIY membranes---we are using porous separators for the moment since they don't give us issues and we are mostly focused on cell/electrolyte R&D).

There is a now a Windows build, and fewer crashes related to file picker UI on Linux.

Downloads and source here: https://codeberg.org/FBRC/mystat/releases/tag/v1.2.2

@Vorg it's always hard to say with those videos because there is no accompanying data

from this paper, seems like nanomaterial synthesis needed: https://www.nature.com/articles/s41560-026-02091-w#Sec25

also they use triflate salts --- that's likely more expensive than the Zn (and, fluorine-containing, with all that entails)

Welcome @stevenhickey , great to have someone with as much experience as yourself here! I doubt you remember me but I think we crossed paths at IFBF in Brussels when I was doing my PhD a few years ago. I was/still am a big fan of Redflow systems, I think a lot of us were sorry to see the news about Redflow a while ago.

Great to hear that you've set up a home lab and are still pushing! Are you focused mostly on Zn-Br still?

Welcome @oliver.schlueter and @nadia_avva ! We are definitely indeed all about the ownership of energy and energy technologies here you are in the right place! We'd love to connect our batteries to a small wind turbine (Piggott-style, probably) as soon as they are large enough... your and Oliver/OSE's wind experience could be very helpful!

Made a longer-form video explaining our open-source battery project and diving into the details of the kit and chemistries we're working with!

It would really help our project out a lot if you could share this with interested folks.

YouTube link (feed the algorithm): https://www.youtube.com/watch?v=xhWBX1eLDr8

And of course, PeerTube: https://spectra.video/w/4wTobcS16Ww5UAZVMWrC9E

Please let me know what you think, comments, criticisms, suggestions---first time I've made a video like this and I have a lot to learn.

Made some Linux AppImages of improved MYSTAT software for anyone who uses it! Also runs on Windows ofc, it's just Python.

https://codeberg.org/FBRC/mystat/releases

Filmed myself building a cell so you can see the whole process start-to-finish! Still working on updating the documentation for the clampable-cell branch. It works pretty darn well without any bolts.

PeerTube: https://spectra.video/w/dxjsd8AR2uAvnA6UMnnb8G

YouTube: https://www.youtube.com/watch?v=hT_5Bde2IVY

It's the same electrolyte formulation as currently in the docs

Link: https://dualpower.supply/posts/lab-notebook-9/

Doing some tests now on this to get my wet lab back in action, here are the conditions and results so far on my blog

A great demo of all the transport phenomena at play in electrochemical systems!

Also, this reminds me of the OpenAFPM project - they also use FreeCAD and provide a dashboard for people to input custom parameters for a small wind turbine generator, there is some FEM, and then design files are output. There is a video demo here: https://www.openafpm.net/cad-visualization

I know a few of the folks behind that project, I'm sure they'd be happy to give input on how to accomplish a similar goal but for flow batteries.