The sentence
咲は電池{でんち}を時計{とけい}に入{はい}れました。
Translates as "Saki put the batteries in the watch" but would would 電池 take を in this case?
The sentence
咲は電池{でんち}を時計{とけい}に入{はい}れました。
Translates as "Saki put the batteries in the watch" but would would 電池 take を in this case?
咲【さき】は電池{でんち}を時計{とけい}に入{い}れました。
As noted in the comments, the verb in your sample sentence is 入【い】れます・入【い】れる, not 入【はい】ります・入【はい】る. The former with れ is the transitive form meaning "to put something into something else", whereas the latter with り or る is the intransitive form meaning "to enter into something". Since the verb in your sample sentence is transitive, it takes an object, and Japanese grammar requires that the object is marked with the を particle.