Coreo skyfactory energy

function round(num, idp)
  local mult = 10^(idp or 0)
  return math.floor(num * mult + 0.5) / mult
end
cell = peripheral.wrap('left')
while true do
if round(cell.getEnergyStored()/80000000*100,2) <= 20 then
redstone.setOutput('right',true)
end
if round(cell.getEnergyStored()/80000000*100,2) >= 80 then
redstone.setOutput('right',false)
end
sleep(60)
end