Vulcan's Favour
CrTe 29
R: Per , D: Sun , T: Ind
Pen +0 , Constant Effect
Constantly repairs the enchanted item , extending the item's life and returning it to usefulness.
The item always seems brand new.
(Base 15 , +2 Sun , +1 2/day , +3 environmental trigger: sunrise/sunset)
Just a variation on the above using Corpus.
Base would be the level of healing as per the Creo Corpus Guidelines on page 130.
Level 35: heal all wounds , to give CrCo 49.
I know this is not permanent healing and removing the item to get healed could be fatal.
Unless you allow that if a permanent healing ritual has enough penetration it will work.
Make you damn near unkillable in combat short of total incineration in one combat round.
I could see items like this being used on animated bodies , by necromancers.
For principes, it seems 100% ok to have a magical item maintening your life (unless you receive a fatal wound which nothing can cure). I have a Tremere magus who has his soul talisman containing a version of this spell, triggered when the item detects he is heavily wounded (InCo spell).
But 2 remarks:
the effect is constant. That means he doesn't activate during the day, and as such can't affect anything which wasn't there at the time of activating. If you take 3 heavy wounds at 14pm, you willl have to wait sunset to be cured. Once it's cured, it remains cured. To avoid it, you may want unlimited (or at least 1 more use) per day. Then if you do give multiple uses to prevent this event, you still need to be conscious to activate the item. What if you become unconscious due to incapacitating for example? I suggest a linked trigger to a InCo effect to detect if you are not in your best shape. And if you are inconscious, you won't be able to lower your parma for the item to allow the item to work. You may want to invest an arcane link to you in the item with a bit penetration or do it in your talisman (since your parma don't bother your talisman).
it could be a good thing to have 2 items working in parallel. Horcruxe like, if you see what I mean. In case one of them is destroyed.
Don't forget you'll need to extend the effect to Touch range, unless you put it into your talisman.
Also you need to clarify how you are using the Duration, because there are two possibilities: first, you can use it in a bind wound fashion: when the item activates, all the wounds you have are healed until the next Sunset/Sunrise, but new wounds are not healed until the next activation. The advantage is that when you take off the item, the effect stays until the next Sunset/Sunrise. Or you can use it in the Vulcan's favor way, with the item constantly healing you, but the moment you take it off all the wounds come back.
And as you say, taking off the item so you can get properly healed is problematic. Still, according to the rules, as long as you lie down, tale off the item and don't move while your allies cast a strong enough healing ritual, it should work.