There's the Soul Siphon perk in the enchanting tree which basically re-charges your weapon as you keep fighting. It's not exactly what you want, but close. There is also Azura's Star. When you get the quest (same name), you may want to do it. Lastly, you can have soul trap on a weapon, which would automatically fill empty gems as you play, so there should rarely be a shortage of "batteries" (this ties in with Aura's Star).