I use OwnTracks on its most aggressive mode "significant change" and it doesn't even have 1% on iOS under "Battery usage".
This particular site's canonical location tag seems to be wrong:
<link rel="canonical" href="http://owntracks.org/features/location/" />I've been walking a lot today, so it has created around 100 pings around Copenhagen over the span of a few hours, and it still haven't used 1% battery on my iPhone 13 Mini.