Skywampa (Etsy) [affiliate link], offers multiple designs of ‘power cell’ style battery decals for both 18650 Lithium Ion batteries and AA batteries, two battery types commonly used in lightsabers. Many of the ever popular Star Wars: The Black Series Force FX lightsabers use AA batteries. Many custom sabers are equipped with a 18650 Lithium Ion battery.
Skywampa Etsy store https://www.etsy.com/shop/Skywampa affiliate link
The battery decal designs pair muted, metallic colors like chrome and gold with other design flourishes like mesh imagery and some aurebesh text.
These ‘power cell’ battery details are uncommon, if not unique. I have not seen any other custom saber companies offering ‘power cell’ battery decals like these. Since lightsaber enthusiasts are often pretty detail oriented about lightsaber appearance, adding a ‘power cell’ decal would be an easy and relatively inexpensive way to give the inside of a lightsaber a more authentic, ‘in universe’ appearance.
Skywampa Etsy store [AFFILIATE LINK]:
Skywampa is a United Kindom based custom lightsaber parts and accessories company. In addition to making battery decals, Skywampa also offers: clamp cards, crystal chambers, stands, and other lightsaber parts.
COVER IMAGE CREDIT Skywampa
Image depicts Skywampa battery decals