Here is a guide @SneakyJoe made on replacing index batteries.
Pimax Sword are not bad but do have some design issues and of course still have not enabled Sense.
They are a nice vive wand redesign.
I have both Index and sword and use both.
Etee Controllers actually have 2 batteries. One in the main controller and one in the SteamVR tracker.
Is it 2025 that EU has mandated devices with batteries need to be consumer replaceable? A lot of new revisions redesigns will be needed.