The used cellphone I acquired a few days ago as payment for setting up an AirPrint printer for a friend was a tad sick in the battery department, dying after 4.5 days on standby. They should go for at least twice that time.
There are two competing battery companies in this town, BatteryZone & BatteryWorld, I visited the latter as it's a new store & I'd not been there before. I enquired how long it would take to get a suitable battery in stock, the phone is six years old now.
The man behind the counter made no reply, just pivoted & took the right battery from a hook behind him.
I rather think he might get more business from me.