mon = nil

for _,pName in pairs(peripheral.getNames()) do
	if peripheral.getType(pName) == "monitor" then
		mon = peripheral.wrap(pName)
	end
end

function getCenter(f, varP)
	if not varP then
		varP = ""
	end
	if (f - string.len(varP) % 2) == 0 then
		return math.floor((f - string.len(varP))/2)
	end

	return math.floor((f - string.len(varP))/2)+1

end

while true do
	local amountOfCells = 0
	local totalEnergy = 0
	local totalMaxEnergy = 0

	for _,pName in pairs(peripheral.getNames()) do
		if peripheral.getType(pName) == "cofh_themalexpansion_energycell" then
			energycell = peripheral.wrap(pName)

			totalEnergy = totalEnergy + energycell.getEnergyStored("a")
			totalMaxEnergy = totalMaxEnergy + energycell.getMaxEnergyStored("a")

			amountOfCells = amountOfCells + 1
		end
	end

	local batteryP = totalEnergy*100/totalMaxEnergy

	mon.setBackgroundColor(colors.white)
	mon.clear()

	mon.setBackgroundColor(colors.green)

	if batteryP < 70 then
		mon.setBackgroundColor(colors.red)
	end

	local max_x, max_y = mon.getSize()
	for x=1, math.floor(max_x*batteryP/100), 1 do
		for y=1, max_y, 1 do
			mon.setCursorPos(x,y)
			mon.write(" ")
		end
	end

	mon.setCursorPos(getCenter(max_x, "Battery: " .. math.floor(batteryP*100)/100 .. "%"),getCenter(max_y))
end