Bigger Reactor Control

sleep(2)
local reactor = peripheral.wrap("back")
local MIN_THRESHOLD = .4
local MAX_THRESHOLD = .8
local previousRodLevel = -1

reactor.setActive(true)
capacity = reactor.battery().capacity()

while true do
energystorage = reactor.battery().stored()
    ediff = (MAX_THRESHOLD - MIN_THRESHOLD)*capacity
    ediffper = ediff / 100

    if energystorage < MIN_THRESHOLD * capacity then
        if 0 ~= previousRodLevel then
            reactor.setAllControlRodLevels(0)
            previousRodLevel = 0
        end
    elseif energystorage > MIN_THRESHOLD*capacity then
        if energystorage >= MAX_THRESHOLD*capacity then
            if 100 ~= previousRodLevel then
                reactor.setAllControlRodLevels(100)
                previousRodLevel = 100
            end
        else
            optimalRodLevel = math.floor((energystorage - MIN_THRESHOLD*capacity)/(ediffper+1))
            if optimalRodLevel ~= previousRodLevel then
                reactor.setAllControlRodLevels(optimalRodLevel)
                previousRodLevel = optimalRodLevel
            end
        end
    end
    sleep(1)
end