I left my phone switched on and in the car when it was being MOT repaired (over three days) and it killed the battery. Replacement. £expensive.
My son gave me my Pierre Cardin (wedding) watch back when he came back from Oxford - he couldn't work there wearing a £5 plastic digital Casio job. It had a dead battery shortly after being handed back. The new one has lasted a few weeks. More £s.
The car was getting sluggish starts - two years of ultra short hops to the supermarket, doctor's etc had done for it. I had hoped the run to Brum on Tuesday would have helped, but no. New one today - you do not want to know how many £s.
Thankfully I have a water wheel for everything else.