It should not be something you notice, and here is the honest version rather than the marketing one.
It runs on Bluetooth Low Energy — the same radio your watch and your earbuds sit on all day — and it works in short bursts instead of holding a connection open. That is dramatically lighter than wifi or a phone hunting for a cell signal it is never going to find, which is what actually flattens phones at sea.
What we are not going to do is print a percentage. We have not measured it across a real sailing with a realistic number of phones aboard, and a made-up number is worse than no number.
So if you run it for a week and it costs more battery than you expected, say so here with your phone model. That is the measurement we actually want, and when we have enough of it we will publish the real figure.
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