Vharging the Magsafe battery with an old charger?
A power supply of min. 20W is recommended. Can you charge the Magsafe battery with an old 5 W or 10 W charger (If you have the time)?
iPhone 12 mini, iOS 14
While the Related Article you came here with says to use a 20w adapter, the following line is present.'
Using an adapter that isn't 20W or higher will result in a slower charge.
I would think that if you are charging it overnight, a lower wattage adapter should get it fully charged. If not, then you will need to invest in a 20w adapter.