My xiaomi portable fast charger clearly charges my girlfriend’s iPhone faster than my high end android device. Doesn’t matter which port, which cable or which android phone. It starts by charging fast but as soon as I link her phone the fast charging speeds go straight to hers and mine just chargers very very slowly.
I’ve got the impression that this may be on purpose or at least has some clear explanation.
Any thoughts?
I think you nailed it in here. Typically, iPhone batteries are smaller. iPhone 15 is 3349 mAh while a Samsung Galaxy S23 is 3900 mAh. The iPhone can get by with a smaller battery due to the OS being developed for specific hardware which allows for better battery life on smaller batteries.