Another Helpful Dad Product Review… Percy the Engine from Thomas and Friends gets a boost now that he is battery-operated. This die cast Battery-Powered Percy Engine includes powerful 4-wheel drive rubber-lined tires, an improved start button for ease of operation, auto-shutdown feature, a working light, and great realistic detail. Battery-Powered Percy from Thomas and Friends will add a new dimension of play to any Thomas track. Requires 1-AA battery, not included. BOTTOM LINE: has issues with staying on track, only buy this AFTER you buy 3-axel trains like the Thomas engine.