i have an amulet with protection spell in a little jar, do i have to charge it or will it work for like forever
It depends on how you put it together initially and what you intended it to do. If you set it up and instructed the spell to work in perpetuity when you made it, then that's what it will do, barring some kind of accident or overload. If you set it up to work for an unspecified while or as a charging station for an object, it will probably need to be recharged at some point.
In my experience (and in the preparations that I use), recharging can be anything from leaving the jar out to catch the light of the full moon, adding it to a containment figure with other objects that are getting a boost, or a full-on replacement of operative contents (i.e. swapping out old herbs for fresher ones, removing degraded components, etc).
So it really sort of depends on how you put the spell together, and also how often the spell is getting "pinged," so to speak, by whatever the magic is protecting you from. For example, if you made a charm to protect you from floods, it's probably going to work harder when heavy rains come as opposed to a long dry summer. I've found that the harder and more frequently a spell like this has to work, the faster it tends to wear out.
I'd start by refreshing it in some fashion on a monthly basis, if you're looking to keep it working longterm, and see how things go.
Hope this helps!
