Merge charge and charger into charging (largest of the three)
This seems like a straightforward merge, similar contents. Might even be worth merging into power unless charging is significantly different.
https://apple.stackexchange.com/questions/tagged/charger?tab=Newest shows that people use charger, charging and charge often together which is pretty useless.
Charge and charger has no user guidance either, which after creating one, despite its redundancy, would prove that they indeed are synonyms of charging.
Separating from power can be done on the basis of hardware of chargers vs battery, power supply etc.