Battery discharge even when phone is turned off.
I bought two iphone 7 as second hand and i find the following trouble: quick battery discharge (half a day autonomy). I thought that both batteries were dead but the result with battery life was a 75% capacity score.
Of course , complete restore as new phone as been done with last ios and battery drain is still present. But what is the most surprising is that the battery discharge occurs also when the phones are switch off. And not a few percent drop around 40% drop for twelve around with the phone completely off. A test with apple staff mentioned that battery was quite good.
And this with 2 different phones (seems ok inside, water indicators are clean) and no physical damage except some scratch on screen. Any help ?
By the way i have tested ios 11.3 to get the new tools related to battery but i didn’t find it...
Is this a good question?