Pour the oil in a skillet so that it is half an inch deep and turn the heat to medium.
While waiting for the oil to heat up, combine the zucchini, onion, and eggs in a large bowl. Stir the mixture to combine. It may get a little frothy, but that's ok.
In another bowl combine the dry ingredients: flour, baking powder, 1/2 tsp of chili powder, salt, and pepper and stir to combine
To finish the batter, add the dry ingredients to the zucchini mixture and fold it all together.
Once your oil is hot (dip a spoon with some batter on it into the oil to test, if the oil starts bubbling in contact with the batter, it's readyou can drop the batter a tablespoon at a time into the oil, frying for 2-3 minutes per side. If you want a more substantial fritter, form the batter into loose 'patties' and fry in oil 3-4 minutes per side.
When the centers are firm, remove them from the oil and allow the to drain on a plate lined with a paper towel.
To make the dip, simply combine the prepared mayo, lime juice, and chili powder in a small mixing bowl and stir it all up.