I have a tendency to give promising tech a bit of a pass on...

I have a tendency to give promising tech a bit of a pass on problems; research and development - at all points - is a difficult job. There are going to be problems, there are going to be issues along the way, there are going to be attempts made that don't pan out for whatever reason. I like the idea of having non-lithium technology available for long duration energy storage; lithium will have its place in the mix, but there isn't enough of it out there to handle all the load, so having alternatives is definitely a good thing.

One of the fundamental problems I think I see with Redflow's performance to date is that they put the tech in the wrong space. With the benefit of hindsight, home storage was never a good fit for it. The round trip energy return that I was seeing was around 70%. Put in two batteries, and the issues of maintenance discharges and energy being lost are reduced - but not eliminated. If I had two batteries, one at 100% and the other at 0%, and the first goes into discharge, it might use that energy to charge the empty battery. Expected level of charge afterwards: around 70%. If that then goes the other way, you end up with around 49% - two discharge cycles and you've lost half the stored energy.

For that reason, you really want these batteries deployed in an environment where there's a reasonably consistent and high (relative to the battery's discharge capability) load: that way, when maintenance comes, the energy can be discharged to the load, and you only have that initial energy loss. That's not a home environment. I actually wrote some computer code (I work in IT) to turn on the electric vehicle charger when maintenance arrived so that the discharge could help top up the car rather than being pushed out to the grid - that's what led me to discover the discharge from the battery being far lower than it should have been capable of. Which is why I say that the new focus of the company is probably the right one: a grid storage setup is probably the best aligned to the battery's capabilities and requirements, given the need for periodic maintenance (and hence discharge).

But as I've already said, the feeling of the company not being completely forthright in its explanation of the warranty issues doesn't sit well with me. I'd be more comfortable if they said, "yeah, it was a huge screwup, this is what happened, this is why we've set aside so much for warranty provisions, and this is what we've done to fix the problems that we've identified" - yes, that would probably have the more risk averse running for the hills, but it would actually give me more confidence in the company's ability to execute on the projects we have on the plate now. Your comment about RFX being a very high risk investment is probably the most neutral way of putting it.

If I had my choice over again, I wouldn't go with a Redflow battery. I now have a couple of Pylontech modules installed (in a 45 RU cabinet - plenty of room for future expansion as funds allow), and they're working very smoothly, far more effectively than the Redflow did for me. Which basically reinforces my comment about the tech having been positioned in the wrong space at the start. It's not a particularly good fit for the home, even with multiple batteries installed, unless there's a consistent and reliable 1 kW (or more) load in the place - and that's not most homes. Grid storage is a better place for the tech, IMO.