What exactly do you mean by a "dimmer"? Everything I have in my home that dims lights is mains-powered, so battery isn't a concern.
I have 45 Zigbee devices in my home, 33 of which are battery-powered. Those are door contact sensors, PIR motion sensors, climate sensors, and a few button remotes to control lighting. They're mostly from Sonoff and Aqara, with a few unbranded Aliexpress devices that identify themselves as TUYATEC, and a couple from Third Reality. In almost every case, the battery life has been extraordinarily good -- well over a year. The only exception is the Sonoff SNZB-04 contact sensor, which seems to need battery changes about every six months. Probably not coincidentally, it's the only sensor that uses CR2032 batteries, rather than AA or AAA. I would happily replace with a slightly larger sensor to get both longer battery life and less e-waste through the ability to use a standard rechargeable AA/AAA battery.
I have a few SmartThings motion sensors that are at 2-3 years battery life, though they use big lithium cells so that isn't surprising. A few sonoff temp/humidity sensors on coin cells seem to be heading for at least a year battery life as well. So far it's only the Ikea buttons that have issues.
Understood. This won't help you much, but I don't think I've ever had to change a remote's battery in the three years since I switched over to Zigbee. I assume their radios wake up only when the button is pressed, which is at most a few times a day, so the battery drain should be minimal. I use Home Assistant with a Sonoff Zigbee-USB coordinator, just as you do.
Those Ikea buttons look pretty ordinary, so I can't think of why they'd have such poor battery life. But they seem to be the only difference between our respective systems.
I do use a few SmartThings branded zigbee sensors but not the hub. I'm using homeassistant with the sonoff efr32mg21 dongle.
I'm well aware of how terrible SmartThings the company is. I'd suffered through their inadequacies until April 2023 when they deleted my account during a failed backup purge. After 3 months of waiting on their support to unlock my hub I gave up and went to homeassistant.
I have 45 Zigbee devices in my home, 33 of which are battery-powered. Those are door contact sensors, PIR motion sensors, climate sensors, and a few button remotes to control lighting. They're mostly from Sonoff and Aqara, with a few unbranded Aliexpress devices that identify themselves as TUYATEC, and a couple from Third Reality. In almost every case, the battery life has been extraordinarily good -- well over a year. The only exception is the Sonoff SNZB-04 contact sensor, which seems to need battery changes about every six months. Probably not coincidentally, it's the only sensor that uses CR2032 batteries, rather than AA or AAA. I would happily replace with a slightly larger sensor to get both longer battery life and less e-waste through the ability to use a standard rechargeable AA/AAA battery.