SO
How many did have more than 5% drops on reboots? I counted only
@Ah0ck from 79 to 67%
In the daily battery thread is has been pointed out, and it's probably true, that Apple waits for the battery to actually drop at least 5% before dropping 1% of the indicator, and then slowly reducing this gap to a 1-2% difference during the day. Maybe they noticed that people are happier to have this delusion of the battery holding the charge more right after charging the phone. Rebooting the phone makes it read the raw battery percentage value again (or it can be checked with Coconut on a Mac). This explains the up to 5% battery drops on reboots.
The more I read this thread and ponder about my experience the more I think this could be just expected behaviour. The batteries on these 13s are quite good, and it can take a while to see the percentage drop. This, coupled with Apple's algorithm, could give the impression of a stuck battery percentage indicator (at any percentage, apparently this algorithm kicks in after a long-ish recharge. Brief charges don't matter).
The only way to falsify this hypothesis is to get more than a 5% difference on reboots or when checking with Coconut. Who else had this? I tried it yesterday, but as I documented I couldn't get more than the usual 5% difference, it was actually 1-2% near the end of the day.
I don't know if I'm right though