Battery optimization is more than just maximizing performance—it’s about making every system work smarter and more efficiently. At EMSYS Design https://emsys.com/battery-testing , we harness the latest technologies to modernize battery service, with hardware built to simplify installations and software designed to reduce the time users spend analyzing data and compiling compliance reports. By combining smart hardware and intuitive software, we help users get the most out of their batteries with less effort and hassle.

We have recently released some improvements to our Android and iOS apps. That mean that when you’re out and about and using a mobile (cellular) connection, your phone will wake up less when its supposed to be idle, thus conserving battery power while Proton VPN works in the background to protect your privacy. https://protonvpn.com/blog/may-2025-update

No matter how many time we wait for this issue, it seems not being taken seriously by Proton so, I suggest using Wireguard app (if you use wireguard connection). The app is free, FOSS, and made by Wireguard.org. I have been using it during 6 months or so on GrapheneOS and performance and battery have improved by a lot on my pixel 8a.
It may seem a bit hard to configure at the beginning but it is the same than configuring an OpenWRT router!
Sincerely I think all that battery draining is caused by the fancy UI and some checks related with "auto" configurations. That's why I prefer a basic app that just "work"

This idea is planned to implement by Proton's Team, I hope the team bringing this optimisation as soon as possible.

I really like Proton's ecosystem and team!!!!

This optimization is pretty much needed on mobile devices particularly.

The battery with ProtonVPN is really terrible, it's true that most other providers work better and consume less, at least on iPhone.

I think Proton's NetShield blocks websites by using directing NDS lookups for blocked domains to the IP address 127.0.0.1. This address is used to connect to the same device the user is using.
This means that instead of connecting to a blocked site, traffic will be sent and received by the user's device. No traffic will leave the device but the device will process the traffic.

Instead, Proton should use the IP address 0.0.0.0 for blocked sites. This address indicates an invalid, unknown, or inapplicable address. It's a "no particular address" placeholder. This means that instead of connecting to a blocked site, the device will stop the connection. No traffic will leave the device and the device will not process the traffic by sending or receiving it.

The extra processing by using 127.0.0.1 instead of 0.0.0.0 uses some battery. Not much, but still some.

This is probably a lot to do with the operating systems more than the apps, but I'm sure there's a little room for improvement.

Yeah it's a neccesary feature.