One of my passions is leading an Awana club each Wednesday night. Awana is a Bible-based kids club that in our case is geared toward preschool through 6th grade students. We want to instill godly character in our kids through the gospel of Christ, Scripture memory, and Biblical lessons, all in a fun and exciting environment. Our core mission is to get as much of God’s Word as we can, as deep as we can, into the hearts of as many children as we can. One of the ways I make it fun is by injecting science experiments into the lessons I teach. Occasionally I document some of those lessons on my blog.Most kids (adults too) have a variety of electronic devices. Cell phones, iPods, tablets, game systems, calculators, watches – all rely on battery power. Forget to charge the battery, and the device will not work. With many of these devices you may get a day or two out of them, but that’s about the limit. Once the battery dies, until it is recharged, the device is useful only as a paperweight!
People are the same way. We need to recharge our batteries regularly. We work, play, serve others, raise our families, all of which requires energy. What sort of ways can we recharge our batteries? Eating right and getting enough rest are two ways. Jesus demonstrated a third type of recharge in Mark 1:35. Early in the morning, He went off by Himself to spend time in prayer, recharging His spiritual battery. He spent His days teaching, preaching, healing, and when necessary, rebuking, but even He – God with skin on – needed to recharge. Prayer was the way He tapped into the ultimate power source.
Now for the object lesson. A bowl full of lemons (other citrus works, as will potatoes) doesn’t look like much of a power source, but with a little effort it becomes a battery. Start with three or four lemons. Roll them around in your hand to loosen the juice inside – the acidic juice acts as the electrolyte that enables the chemical reaction to work. Cut two small slits in each lemon; insert one copper and one zinc electrode into each fruit. Radio Shack has ready-made electrodes, but old pennies will work for the copper, and zinc-plated (aka galvanized) nails or washers from the hardware store can serve as the zinc electrode. The electrodes should be pushed well into the fruit, but must not touch – that will short-circuit the reaction.
Each lemon is now a small battery cell, likely generating in the neighborhood of 1 volt. In order to do anything useful, you will need to connect a few cells in serial. Connect the copper electrode from one fruit to the zinc electrode in the next, leaving one copper electrode free at one end, and one zinc free at the other. Insulated wire with alligator clips at the ends is a convenient way to connect the electrodes together. Electricity works such that when cells are connected in serial, the voltage potential of each is added together; the result is a multi-cell battery that should produce several volts. You can test the voltage using a multimeter.
Then comes the fun part: connect the remaining electrodes to opposite ends of a LED. Make sure the LED you use specifies a voltage lower than what your battery produces – you want to be sure your battery creates enough voltage to light the bulb. With a little luck, the bulb will light up.
How does this work? A battery converts chemical energy into electrical energy. In our case, the zinc electrode slowly dissolves into the acidic juice. When it does so, it leaves some electrons behind; these electrons flow through the wire to the copper electrode. The moving electrons are what we call electricity. *
Just as the lemons don't give us any power until we connect things together properly, we can't enjoy the power of prayer unless we actuallly spend time in prayer. The power is right there available to us, but it's up to us to tap into it.
* Yes, I know this is an extremely over-simplified description, but keep in mind I am teaching young elementary students! Wikipedia has a much more thorough explanation of the process if you are interested, but for younger kids this is enough.