Higher wattage motor allows for sucking in heavier bloons such as lead bloons
Heavy Duty Suction is the second upgrade on the first path for the Bloonchipper. It allows the Bloonchipper to pop Lead Bloons. Although any Bloonchipper can suck up Ceramic Bloons in most games, the Heavy Duty Suction upgrade is required for sucking up Ceramic Bloons in BTD Battles Mobile.
The icon for Heavy Duty Suction has been altered in Bloons TD Battles Mobile after the update 3.4 nerf, it now shows both Leads and Ceramics getting sucked in. In addition, the description is also changed to include Ceramics.