I have luckily never had a battery issue with any of the numerous Roku remotes I have, but I never use headphones or voice. There's plenty of Roku remote apps out there (some of which cost money), but just so you know, the official Roku app is free.
Roku Mobile App - Free for iOS® or Android™ | Roku
@renojim I don't have a phone, but (I'm using a fire tablet with the Roku app), but hypothetically, is it possible to use a non-activated burner android phone & your home WiFi?
On both of the items I have had with the WiFi Remotes the battery life issues had come & gone & reappeared, I'm assuming something with the software upgrades.
@Strega2 I never use the voice either (not sure if there is a headphone jack, but I never use it. I imagine that would be a drain on the battery.
I have been up to 12.5.5 now for a month or so, I've been through at least one set of batteries.
@Bismarck318, it should be. As long as the phone can connect to your network and you have the app on it, it should work.