Rigellian Batteries

 were a limited-time currency released on December 5, 2017, as part of Act 1 of The Invasion Before Christmas 2017 Event. It was used as the event's Act 1 Personal Prize currency.

How to Obtain
could have been obtained in the following ways:
 * Tapping Robo-Funzos yielded 12 per Robo-Funzo tapped.
 * Tapping Robo-Funzos in friends' Springfields yielded 1 Rigellian Battery per Robo-Funzo tapped; however only the first thirty friend actions yielded.
 * Playing the Re-Gifting Machine Minigame yielded which varied on the number of Robo-Funzos tapped and if it was a win or lose per game.
 * Completing daily challenges related to the event awarded 450 per qualifying challenge.
 * Completing part 3 of the main questline yielded 400.

Personal Prizes
The following table displays the prizes won upon collecting.

US$