[NTLK] OT: iPhone Battery connection - or?

[Berthe Marie Willumsen]

OK, I’ll bite on an OT:
My 5s iPhone exhibits weird and unpleasant behavior and I ask for advice:
It suddenly dies - black screen.
If I try to wake it very soon after, by pressing home screen, I may get a pic of a battery drawing with a tiny red stripe at its bottom.Or not.
But the iPhone at the time of ‘death’ may have told me anything from battery levels in the 70’ies to levels in the 20’ies.
Only charging will revive it, and always, it reacts the same way:
It sometimes briefly shows the empty battery (red stripe)
The apple logo lights up
the vibration sound comes on after - is it 7 sec?
the lock screen comes on - another 7 sec? Maybe the absolute timings are different from what I state here, but always the same.
I can then log in, activate sim - and the battery level shows what it did before it died - 70’ies or 20’ies or whatever.
If I unplug it soon after revival it tends to die again soon, with the same rigmarole.

So far, it always revives when plugged in. Been going on for about a month or more, because I’m chicken to give it to some shop to fix.
It may tend to die when I ask it to do ‘heavy?’ things: update apps as I look for travel assistance or search - don’t know….

Anyway, knowledgeable and always on and thinking techs:
Is the battery dying?
Is the connection to the battery dying?
Is something else going on?

What should I get fixed at the shop (provided I find one I trust)?

Berthe

MP2100, still alive, but sleeping pt…..