spellcasting class dedication preparing a staff

[x x 342]

Use case: fighter takes cleric dedication, does NOT take spellcasting, and buys a staff of healing. The character has NO spell slots.

Can the character add charges to the staff during daily preparations? If so, how many? Are the answers to these questions documented in the rules somewhere?

[Bluemagetim]

None. When charging a staff "that staff gains a number of charges equal to the rank of your highest spell slot." pg 278 GM core

[NorrKnekten]

You are sadly not going to get any usage of the staff that way.

Staff Rules

GM Core pg. 278 Casting Spells from a Staff wrote:

A staff gains charges when someone prepares it for the day. The person who prepared a staff can expend the charges to cast spells from it. You can Cast a Spell from a staff only if you have that spell on your spell list, are able to cast spells of the appropriate rank or higher, and expend a number of charges from the staff equal to the spell's rank. Casting a Spell from a staff requires holding the staff (typically in one hand) and Activating the staff by Casting the Spell, which takes the spell's normal number of actions.

It also gains charges equal to the highest rank spell you can cast, So not only does it not gain charges, you cant cast the spells to begin with. Can still use the cantrips in it though.