energy

redstoneSide   = "right" -- Where to output redstone signal
redstoneState  = true -- What state to put the redstone in when the chosen limit hits
energyPercent  = 10 -- what percentage to react on
reCheckTimer   = 5 -- How many seconds to wait before it checks again
EnergyCellSide = "left" -- Which side of the computer the energy cell is on

enCell = peripheral.wrap(EnergyCellSide)
mon = peripheral.wrap("top")

function getEnergy()
  return enCell.getEnergyStored("unknown")
end

function getMaxEnergy()
  return enCell.getMaxEnergyStored("unknown")
end

function getEnergyPercent()
  return math.floor(getEnergy()/getMaxEnergy()*100)
end

while true do
  power = getEnergyPercent()
  mon.clear()
  mon.setCursorPos(1,1)
  mon.write(power)

  if power < energyPercent then
    rs.setOutput(redstoneSide, redstoneState)
    mon.setCursorPos(1,2)
    mon.write("ON")
  else
    rs.setOutput(redstoneSide, not redstoneState)
    mon.setCursorPos(1,2)
    mon.write("OFF")
  end
  sleep(reCheckTimer)
end