The battery in the Spark is a 3.7v 405mAh pouch battery with 3 leads, red, white, and black. It is adhered to the top part of the enclosure with a double sided adhesive. The battery can be purchased online for less than $20. The connector is difficult to find online.

The touch bar is connected with a black wire. It is not necessary to remove or mess with this while replacing the battery.