Revised and re-done, fully working battery in Minecraft

It's quite compact, too. Works on 10 second intervals. It uses 2 tree saplings to smelt one oak wood block. There's a small chest full of the oak wood and a large chest full of saplings since two are needed to smelt one log. A comparator detects there's things in the furnace and sends power into a block and a spot of redstone dust next to it. Said dust goes into a repeater and the repeater powers a block with redstone dust on top. This redstone powers a hopper which goes into the top of the furnace, keeping things from going in and out of it and that redstone goes around to power a repeater which goes into a block next to that hopper. Beneath that block is another hopper going into the side furnace.
Also, below the block being powered by the comparator is redstone dust which powers a repeater which comes out of that block. This repeater has one spot of redstone coming out of it. The side of that block, going with the line of the redstone dust is a facing up sticky piston with a block on top. The redstone dust powers a repeater on two ticks delay which powers a block with a redstone torch on top. There is a block on top of that torch with a sticky piston on top of it. This piston extends and sticks to the block the repeater is powering to keep both hoppers inactive.
I've explained how it's set up, but to explain how it works is another story, so I'll give you a short explanation:
Since it takes two saplings to cook one oak log, this system allows two saplings and one oak log into the furnace. Once the oak log is turned into coal, there's a hopper coming from the bottom of the furnace into a double chest where your charcoal will be stored since that's what you get from smelting logs. Once cooked, the cycle starts again. This is to keep the furnace from flooding.
So, if it weren't for this, the furnace would be full 64 of logs and saplings. When you turn off the laptop, these things, which keep the laptop working, cook, so you'll lose battery life. This system moderated it by only allowing two saplings and one log into the furnace to cook at a time, so when you turn it off, the log and saplings in there will finish smelting but the hoppers will stay powered so you lose no more logs or saplings.
How the battery turns off the laptop:
There is a comparator coming out of the chest your charcoal will be stored in. This comparator will power a line of redstone and will give a stronger signal as the coal builds up. Once all the logs are turned to coal and in the chest, the signal will be strong enough to reach a block to invert a redstone torch which will invert another and this one will reset the t-flip-flop used to turn on and off the laptop. That second torch will remain on, so when you try and give the laptop power to turn it on, it will not work.
Funny thing is that this 'battery' does NOT power the laptop in ANY way-- it's just a 4.8 hour delay to turn it off xDD