E-Eco Tad Electric Assist Tadpole. The E-Eco Tad Electric Assist Tadpole is engineered to incorporate a power system that boasts a 350-watt pedal-assist rear-drive motor along with a 36 volt / 10.4 Ah Li-ion battery pack for speeds up to 15 mph. This is our most affordable pedal-assist tadpole trike, but just because it's affordable doesn't mean that it's not full of features. It has a fully adjustable mesh-back saddle with a padded bottom that keeps you cool and comfortable on long outings. Plus, there are spare bottle mounts on the seat frame to let you carry plenty of hydration for the long hauls.