I do this since I carry my phone around pretty much all day and thought, "Hey, why not? Batteries can store more than one type of energy, right?" So here I am, incase anyone wants to draw inspiration from this. Also sorry about formatting I'm on mobile.

Passive charging

Just keeping it on your person and using it is embedding your energies already. I mean, you're already doing it if you read this post on mobile (and I'm doing so as I write this), but this experience is mundane and commonplace. I feel like very little energy is produced this way but that may be a good thing depending on your situation.

Something as simple as rubbing the case with intent or even taking the time to admire your phone may produce more energy, but this might be considered as actively charging your phone.

Active charging

Since ADHD is a thing, I often have atleast 2-3 songs on an endless mix (and honestly not even good transitions imo) constantly changing all the time. I figure I can put this to good use by having a little rhyme I sing in my head from time to time when I'm not using my phone if it's just in my pocket or if I'm carrying it in my hand as I sit/walk/whatever:

Charging my phone, I'm charging my phone/Not with a charger but with my soul!/Charging my phone, I'm charging my phone/I can use the juice when I get home!

To me, this is very catchy and often gets stuck in my head, even when I don't have my phone on my person. I'd imagine saying this over and over in your head will have the same, if not greater effect. It doesn't have to be this exact rhyme; you can use a simple mantra of "charge", or a more elaborate chant. Whatever works for you. Also while this plays, I imagine a shiny cord going from myself to my phone's charging port slowly transfering my energy to my phone's battery with each repetition of the rhyme.

If visualisation isn't your thing; maybe holding some thread or ribbon of any length that's halfway tucked into the phone's case or just sticking out but not easily removeable w/o taking off the case. (You can also use the phone charger itself plugged into the phone normally if you're comfortable with that). Being aware of the phone, your charging cord of choice, your hand or leg, and the connection between them will also have similar (and maybe a more potent) charging effect. If you'd like, you may find it helpful to imagine a one-way flow of energy as described prevoiusly.

Transferering stored energy

This whole post is really useful for me since I'm often just dead tired from the day's many challenges. Some days I'll practice writing in my book of shadows, some days I fall asleep right after I crawl into bed and won't wake up until well after sunrise.

When I want to transfer the personal energy from my phone I imagine detatching the cord from myself to wrap around my book of shadows or my gemstones or whatever else I feel might need some energy at the time. Sometimes I'll wrap the cord around my pencil when practicing my cypher to help with memorization.

For those who prefer using a physical cord (people who like visualization or find it easier can do these too) you can do the above as well as;

bookmark your favorite page of a book so you can have an aspect of it reflected whithin yourself (or to help a spell/hex/thing along),

make a sigil with the cord and see what happens (untested),

wrap the cord around your tarot deck if you tend to move around a lot at night and are afraid of damaging your cards unintentionally,

to be honest you can charge just about anything that needs charging with this spell(?)

Untested ways of charging your phone with other types of energies and other uses for stored energy

Placing phone under moonlight

Using energy for a protection ward

Dancing to your favorite music

Making your phone into a temporary black mirror

More things that I'll think of later