They would need to have the battery in stock AND be advised by google to authorise replacement under the scheme. It's a Google scheme, not EE's responsibility, and only EE stores are approved for some reason. The only ones within a day trip pf me don't have the part in stock (I doubt any will - very unlikely for what is considered an old phone). The ones within an acceptable distance of me aren't in the scheme. Any of them, whether Google says 'walk in' or not, will most likely end up sending it back to the repair centre who DO have parts. I spoke to various EE stores, I spoke 'a bit grumpily' with Google, and Google couldn't provide any options which did in fact solve the problem nor have any way of identifying a store who would have the battery in stock and hence be 'walk in' in reality. So not exactly impressive. Overall cost and hassle of just buying a used Pixel 5 (same size, probably just enough 'better' than it won't feel a total waste) is probably less than trying to replace, and claim the derisory £40 ($50) 'appeasement' instead.
After a couple of days I'm finding the battery behaviour is improving. I think it's more to do with calibration than anything, so the chips or coding in just *some* batteries is going to be not playing well with the upgrade. Still reduced and still a bit oidd (no 'fast charging' happens, seems to randomly all night or an hour to fully charge, won't get to 100% without unplugging then plugging back in again...). But it's way better than post upgrade day 1 when it got to 0% in a few hours, and it lasting a bit over a day again.
