Place the potatoes in a bowl of ice water for 20-30 minutes.
Heat the vegetable oil in a deep heavy skillet, or deep fryer to 330° F.
Drain the potatoes and dry them thoroughly with a kitchen towel.
Carefully, fry the potatoes, about 1 cup at a time, in the hot oil for about 2 minutes.
Remove with a slotted strainer and drain over paper towels.
Repeat until all potatoes have gone through the 1st frying cycle.
Increase the oil temperature to 370°F.
In a large bowl, stir together the flour, baking powder, salt, onion powder, and garlic powder. Next, add in the ice cold beer. Stir to mix.
Add a little more flour on the fish fillets and toss to coat.
Add the floured fillets to the batter and let the excess batter drip off.
Carefully add the fish to the 370°F oil.
Cook until the fish is golden, 2-3 minutes.
Drain over paper towels.
To finish the chips, fry the pre-cooked potatoes in the 370°F oil.
Fry until they are golden brown, and crisp, about 4 more minutes.
Drain over paper towels.