gen = peripheral.wrap('left')
local nM = gen.getMaxEnergyStored('unknown')

function Inf()
    nE = gen.getEnergyStored('unknown')
    nP = math.floor((nE/nM)*100)
    energy = (nE.."/"..nM.." "..nP.."%")
    clock = textutils.formatTime(os.time(),false)
end

if nE == nil then nE = 0 end

while true do
    term.setCursorPos(1,1)
    local nEo = nE or 0
    Inf()
    if nEo < nE then
        print("Charging   ")
    elseif nEo > nE then
        print("Discharging")
    else
    print("No change  ")
    end

    print(clock.."  ")
    print(energy.."      ")

    sleep(1)

    if nE < 1 then
        redstone.setOutput('left',false)
    elseif nE >= nM then
        redstone.setOutput('left',true)
    end
end