Avatto TRV07 vs. Sonoff TRVZB

Hi all.
I need at least ten TRVs for my home, so I’m trying to find a modest Zigbee2mqtt-controllable TRV for the lowest possible price.
For starters, I bought the Avatto TRV07 and the Sonoff TRVZB.
Both are working, but Avatto requires an external converter. It’s no big issue, but worrying is battery consumption.
Installed at the same time, let’s say two weeks ago, and operating under similar conditions, Sonoff is still at 100% battery while Avatto dropped to 90%.
Does anybody have more experience with this?
Thanks in advance.