These Roku remotes are a bad design plain and simple. The only Roku remotes that work properly are the simple IR remotes that you don't pair to your Roku and never had private listening. With those remotes you can use two AAA batteries for pretty much an entire year before having to replace them and since they don't get paired to your Roku the battery indicator never pops up on the screen, because the Roku doesn't know the battery level.
It's the enhanced voice remotes that are the problem, they drain batteries way to fast and then you get spamming of your TV screen with battery level warnings that you can't disable. The best thing you can do is use one of the standard IR remotes or get a universal streaming player remote that works with Roku to control TV volume and power. This way you'll get the most out of your batteries and you'll never get any messages popping up onscreen about your battery level. Unfortunately that option won't work if you have a streaming stick because it goes behind your TV and there is no line of sight to your remote, but if you have a Roku player on your TV stand IR remotes are the better option.
In my opinion Roku needs to completely redesign these voice remotes because there is a terrible design flaw somewhere in the hardware, killing your batteries too quickly and then the pop up annoyances on your screen constantly telling you your battery level when you don't want to see it. Roku won't even update the remote settings so you can turn the battery notification off, Roku just doesn't care. Their solution is always to ask for your serial number, ask you to factory reset your Roku, unpair and repair your remote or sometimes send you a new remote which also doesn't work properly.
The moderators on here who monitor all of these remote issues just seem to be going down the same troubleshooting script of steps that don't work and if they do actually report the issues to the people responsible for designing the remotes they don't seem to care. It's such a shame because Roku is a great product but the remotes are completely flawed, after many years nothing has changed, not very encouraging for a company to still have these issues after so many complaints and no real solutions have been implemented.
