The buffs from Sol will be active upon entering all the floors in the Ascent, but it will not activate the effect of XIX - The Sun.
In Home, the buffs from Sol will activate after sleeping in Mom's bed or defeating Dogma's first phase.
On floors with multiple bosses (The Void, XL floors, the Red Redemption challenge), one random boss room is shown.
In The Void, only the randomly selected Boss room will grant Sol's effect.
Does not activate with bosses killed during Boss Rush.
Despite being on a different floor, Sol's effect persists for ??? and thus contributes to the Hush fight.
Upon defeating a multi-segment boss where all pieces die at the end (Chub, C.H.A.D, Carrion Queen, etc.), the effect activates once per segment, leading to an effective +3 luck and +9 damage until leaving the room, after which, the extra bonuses will be removed.
If Sol is obtained in Greed Mode, through Spindown Dice or as a starting item for Eden, the effects will activate when entering the main room for the first time. In addition, it will activate each time a boss wave is completed.
Sol will not activate during the final stage in the mini-boss fight before Ultra Greed.
The Battery: Provides an extra level of charge if the item was fully charged when the boss was defeated.