I think there are two parts to what is going on: the electrode stack, and the rest of the battery.
The electrode stack is the heart of the battery, and is the one component that currently has a full 10 year warranty (..unfortunately..). Manufacture of the electrode stack was only outsourced to Flex last last year iirc. It seems likely that this is the component that RFX need to make sure is absolutely right (and by implication some issues may have arisen with early flex-manufactured units??).
Manufacture of the rest of the battery (plastic containers, pumps, and electronics) was outsourced to Flex previously. None of this is technologically complex, so no reason to assume there are/were quality issues here. On the other hand, this part of the battery was designed to be manufactured and assembled in a Brisbane factory - bit of a cottage industry. It would not have been designed to be manufactured in large volumes in a highly automated manufacturing facility. This part is the key to the cost reductions: as Simon said, the ZBM-next is the same battery. He means that it will have the same electrode stack and control electronics, so will be functionally identical. What will be different in the ZBM2 is that the rest of the battery will be redesigned to facilitate automated manufacture/assembly. It will have fewer parts, be simpler to put together, and may be more compact (and I can't see how it could be uglier ). But it will store the same amount of fluid as the ZBM2, and will still have a couple of pumps and the same control electronics. And hopefully it will be a lot cheaper to make.
). But it will store the same amount of fluid as the ZBM2, and will still have a couple of pumps and the same control electronics. And hopefully it will be a lot cheaper to make.
(20min delay)