Power UP! The Challenge

The Royal Society of Chemistry and the Higher Education institutions involved in this project are not liable for the actions or activities of any reader or anyone else who uses the information in these resource pages or the associated materials. We assume no liability with regard to injuries or damage to property that may occur as a result of using the information contained in these resources. A full risk assessment must be carried out before undertaking any of the practical investigations contained in this website and associated resources. We advise teachers to refer to either the CLEAPSS website or SSERC website for up to date health and safety information when planning practical activities for children.

All materials are ©Royal Society of Chemistry and the Higher Education institution responsible for setting the challenge and are freely available to share for educational purposes. Whilst educators are free to adapt the resources to suit their own needs, acknowledgement of copyright on all original materials must be included. Rights to original images included in the resource are for the use of the Royal Society of Chemistry and the Higher Education institution responsible for setting the challenge only – as such, these images may only be used as part of this resource and may not copied into or used in other materials.

 

For this challenge, and to aid you in completing a full risk assessment, you will need to be aware of the following:

1. Work in a well-ventilated room and only connect the circuit for short durations (less than 10 seconds at a time), which should be ample time to assess the brightness of the bulb or to take measurements on the multimeter. 

2. When testing the constructed battery, there is the potential for a short circuit to occur. Care should be taken to ensure the 'wires' are only connected through a component (e.g. bulb or multimeter).

3. When connecting the circuit, wires should be held using the insulation, or, in the case of the aluminium foil 'wires', by holding an insulated part of other components, e.g. the bulb, and using this to complete the circuit.

4. Where liquids are used to create a battery, there is the potential for spillage. Care should be taken to keep the wires and battery dry, except where specified. 

5. One option within the challenge is to cut up an aluminium can to create discs. The cut edges may be sharp and care must be taken when cutting and handling the can to avoid accidental skin damage. 

6. There is the potential for the bulb to overheat and break if you make a battery of higher voltage than the bulb (e.g. a 6 V battery for a 3 V bulb). Care should be taken to adapt the battery to an appropriate voltage for the bulb. If using purchased batteries, ensure the batteries are of the same voltage as the bulb (you can include additional batteries to achieve this, e.g. two 1.5 V batteries for a 3 V bulb). If purchasing batteries, we would advise using zinc chloride C-type 1.5 V batteries.

7. When using household items please read the safety information provided by the manufacturer.   

Part I - Making Batteries
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Please make sure you read our safety notice prior to starting any investigations. 

The first part of this challenge involves making a battery yourself. This is particularly difficult, and it can take a while to make these batteries work, so you may choose to skip this part and just buy batteries for the second part of the challenge!

If you choose to undertake this tricky part, we'd love to hear about how you've got on - check out how to contact us in the 'celebrate!' tab.  

When making your own battery, a multimeter, which can be bought online quite easily, is very useful to help find any problems with these DIY batteries and can be used to help test them even if the bulb isn’t glowing. 

There are two methods to choose from, outlined below: a coin battery, and an ice cube tray battery. Please choose either one depending on the materials you have available. The coin battery is quicker to set up in general but may give you a smaller voltage.  

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You will need: 

  • Up to 20 1p coins – make sure you clean them before using them by soaking in coke/vinegar for a few hours

  • Up to 20 pieces of aluminium foil folded into four layers and cut to the exact same size as the coins, or aluminium cut from a drinks can. Aluminium from a can may work better than foil if you are struggling to make the battery work. 

  • Sharp scissors if cutting an aluminium can

  • 20 pieces of paper, cardboard, or paper towel (cut to the exact size of the coins)

  • Small bulb – one from a torch works best. Try to find the lowest current rating you can (preferably below 0.5 A), and a voltage below 12 V. A 3 V LED is ideal. 

  • Vinegar 

  • Coke 

  • Salt 

  • Voltmeter/Multimeter (optional, yet recommended)

  • Tweezers (optional) 

  • Water  

  • Insulated electrical wire (optional), and a wire stripping tool (optional) 

  • Extra aluminium foil (if not using electrical wire) 

  • Insulating tape/electrical tape 

  • Cling film (optional) 

  • Sandpaper (optional) 

  1. First, clean your coins by soaking them in coke, checking them every 30 minutes to see if they are clean and shiny. Remove from the coke, rinse and wipe clean. If you do not have coke, you can use vinegar, or, alternatively, rub the surface with sandpaper until shiny.  

  1. If using aluminium from a drinks can, the outer coating must also be removed first with sandpaper. Take care when cutting up and sandpapering the can as the edges can be very sharp. 

  1. Then mix salt into approx. 100 mL vinegar until no more salt dissolves. You may need to stir for some time until it dissolves.  

  1. Soak a piece of cut paper towel in the vinegar and salt until it is completely wet. 

  1. With the tweezers, carefully place the paper towel on top of a penny coin so it covers the whole surface. 

  1. Place a piece of layered cut foil (four layers)/drinks can on top, in the centre of the paper.  

  1. Working quickly and carefully, continue stacking in the order penny, paper towel, foil, penny, paper towel, foil…. until all your coins and pieces have been used up. Make sure to end the stack with a piece of foil. Each layer should only touch the layer above and below. If the pieces of paper are too large, they may hang over the edge too much and touch the layers below the coin. If this is the case, they must be trimmed so they only touch the coin below.  Below is an example of a stack.  

 

 

  1. Wrap the stack in cling film to secure it (optional), making sure the penny at one end and the foil at the other end are uncovered, as these are where you will connect it to the circuit.  

  1. Using a stack of 12 cells (one cell is one penny, paper, foil layer), a voltage of around 4.9 V can be measured! Would you get a higher or lower voltage with more cells (more layers)? 

 

To test your battery, you need to attach it to a bulb! 

  1. If you have electrical wire, remove a small piece of insulation from each end with a wire stripping tool. You will need two wires like this.  

  1. If you don’t have electrical wire, prepare two pieces of foil ‘wire’ by taking a piece of aluminium foil approx. 12 cm wide by the length of the roll. Fold this foil in half along the short edge and then fold in half again along the long edge. Keep folding in half along the long edge until you cannot fold anymore. You should have a length of aluminium 'wire' that is half the length of the original aluminium tube. Carefully make the ends slightly wider by teasing out the foil so they can attach better to the battery and bulb. Why is this better?  

 

 

  1. Attach a piece of tape to each end to allow you to stick it to the battery or bulb. Then, using the tape, stick one piece of wire to one end of the coin stack (so the wire is touching only the penny) using the electrical/insulation tape, then stick the other piece of wire on the other end of the coin stack, again using electrical/insultation tape, so it touches only the foil.  

  2. The loose ends of wire can now be attached to a bulb. Only attach one wire to the bulb. The second should only be connected when you’re testing the circuit, making sure you only touch the plastic of the bulb or the insulated part of the wire when you connect the second wire.  

  1. If the bulb is a screw fitting, carefully wrap one loose end of wire around the threaded part (see photo below). When the bottom of the bulb touches the other piece of wire, it should light up. 

 

 

  1. If an LED with two pins is used, wrap wire around one of the ‘legs’. Then, when the other leg touches the other piece of the wire, the bulb should light up. If this doesn’t work, try swapping which leg is attached to which side of the battery.  

 

 

  1. If you get your bulb to light up, try reducing the size of your stack, using between 10 and 20 layers. How does this affect the brightness of the bulb? Why? 

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You will need: 

  • A plastic ice cube tray.  

  • Lemon juice, vinegar, or salt water.  

  • Screws, as many as there are ‘cells’ in the ice cube tray. Try to make sure they are all the same type of screw  

  • Copper wire, or aluminium foil ‘wire’ as discussed above for the coin battery, cut into as many pieces as you have cells in the ice cube tray 

  • Insulating tape/electrical tape 

  • Small bulb (e.g. a bulb from a torch). The lower the current, the better. This will be given in Amperes (A on the packaging). Less than 0.5 A and less than 12 V is recommended.  

  • Voltmeter (optional, but very useful) 

  • Blu-Tac, or similar (optional) 

  1. Fill the ice cube tray with lemon juice or vinegar or salt water*. Leave some space at the top so the water can’t cross from one ice cube mould to the next.  

      *If you are struggling to get a working battery, we recommend trying vinegar with dissolved table salt. 

  1. Wind copper or aluminium wire around the head of each screw 2/3 times, then form the rest of the wire into a ‘hook’ as in the picture below.  

 

 

  1. Place one screw into the first cell and hook the tail of the wire into the next cell along. This should also hold the screw into place. Blu-Tac can be used to secure the screws if needed. It doesn’t matter if the screw head touches the water, but make sure the copper wire going from one cell to another doesn’t touch the screw in the next cell. The wire should only touch the screw it is wrapped around.  

  1. Repeat with each cell, going around anticlockwise. 

  1. In the last cell, leave the wire hanging over the edge out of the ice cube tray. This will be your connection to this end of the battery.  Make sure the wires are as far into the liquid as possible.  

  1. In the first cell, add an additional piece of wire sticking into the water and dangling out of the ice cube tray. Your battery should look like similar to the picture below. 

 

To test the battery, you can use it to light a bulb! Only stick one wire to the bulb. The second should only be connected when you’re testing the circuit, making sure you only touch the plastic of the bulb or the insulated part of the wire when you connect the second wire. 

 

  1. If you have electrical wire, remove a small piece of insulation from each end with a wire stripping tool. You will need two wires like this.  

  1. If you don’t have electrical wire, prepare two pieces of foil ‘wire’ by tightly folding aluminium foil. Make the ends wider so they can attach better to the battery and bulb. Why is this better?  Attach a piece of tape to each end to allow you to stick it to the battery or bulb.  

  1. If using LED pin lights, connect one pin to one end of the battery, and the other pin to the other end. If it doesn’t light up, try changing which way round it’s connected. 

 

  1. If the bulb is a screw fitting, carefully wrap one loose end of wire around the outside part of metal below the bulb (staying away from the base of the bulb). When the bottom of the bulb touches the other piece of wire, it should light up.  

  1. How does changing the number of ice cube tray cells affect the brightness of the bulb? Does changing the metal of the screws or wire affect this? 

  1. If using a multimeter, you can check the current across each pair of cells to see if there is a problem with the circuit. No current, or a very low current means the connections are bad. Otherwise you may have to check all the screws are wrapped with enough wire, and make sure each is sufficiently pushed into the liquid. Additional problems may be from the liquid overflowing from one tray to the next one, the wires may be frayed and not touching enough of the screw, or the wire from one cell may be touching the screw from another cell.  

  1. If your current is very low, this may be why the bulb isn’t lighting. Try adding a bit more salt and warming the water to help it dissolve. Otherwise, clean the screws thoroughly, and keep wires as short as possible, and as close to the screw in the next cell along (without them touching!).  

  1. With a 12-cell tray, around 6 V was initially achieved. Does using more cells change the voltage? 

 

 

 

 

Part II - Testing Conductivity
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Please make sure you read our safety notice prior to starting any investigations. 

The second part of this challenge is designed to test the use of saltwater as a conductor of electricity. 

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You will need: 

  • One of the two DIY batteries from Part I of this challenge, or a bought battery. If using the latter, use the voltage specified on the bulb you have; do not exceed the voltage on the bulb. 

  • A small bulb, as used in Part I of this challenge. A bulb from a torch generally works well.

  • Aluminium foil 

  • Insulated copper wire and wire cutters, or aluminium foil ‘wire’.   

  • Insulating tape/electrical tape 

  • A glass or plastic beaker/jug 

  • Water and plenty of salt 

  1. If you have electrical wire, remove a small piece of insulation from each end with a wire stripping tool. You will need three wires prepared in this way. These are your connecting wires.   

  1. If you don’t have electrical wire, prepare three pieces of foil ‘wire’ by tightly folding aluminium foil. Have a look at Part 1A Method: Testing your Coin Battery for details on how to make aluminium wire. Make the ends wider so they can attach better to the battery and bulb. Why is this better?  Attach a piece of tape to each end to allow you to stick it to the battery or bulb.  

  1. Then, make two electrodes from the aluminium foil. Fold the foil into two, wide strips and form the top into a hook (so they hook over the edge of your glass). These are your electrodes.  An electrode is a conductor through which electricity enters or leaves an object, substance or region. Tape a piece of connecting wire to each one.

  1. Using the connecting wire, attach one electrode to one side of the bulb. If the bulb is a screw fitting, carefully wrap one loose end of wire around the threaded part (see how to connect bulbs in Part I of the challenge). If using LED pin lights, connect one pin to one of the electrodes.   

  1. Use a second piece of wire to connect the other electrode to one side of the battery. Generally, the connections will be better if you make the end of the wire flatter and wider. Why is this?  Using the tape, attach the connecting wire as tightly as you can to the battery.  

  1. Attach the third piece of wire to the other side of the battery. This will connect to the bulb when you are testing the circuit (see connecting bulbs in Part l of the challenge). Only attach one wire to the bulb. The second wire should only be connected when you’re testing the circuit in Step 8, making sure you only touch the plastic of the bulb or the insulated part of the wire when you connect the bulb. 

  1. Before proceeding you should check that the voltage of your bulb matches the voltage on your battery, as you may need more than one battery depending on the voltage of your bulb. For example, a 3V bulb would need to connect two 1.5V batteries. To do this, simply make an additional connecting wire and add this between the batteries, making sure you connect opposite sides (connect the + side of one battery to the – side of the other). 

  1. To test the circuit, connect the bulb to the battery and touch the two electrodes together. The bulb should light up. Ensure you have enough contact between your electrodes. If this circuit isn’t working, check all the wires are securely attached to bulb, battery and electrodes and try again. The set up should look like the picture below.  

  1. Next, fill the jug with tap water, and place the two electrodes on opposite sides of the jug, making sure they are not touching. Touch the bulb to the second piece of wire to complete the circuit. The circuit should look like the picture below. What happens to the bulb? 

 

  1. Remove the electrodes and dissolve a teaspoon of salt into the water. Now add the electrodes back. What happens to the bulb now? 

  1. Investigate what happens when you change the amount of salt added to the water. Why does this happen? If nothing changes, try moving the electrodes closer together or further apart in the liquid, making sure they don’t touch.  

  1. If using a multimeter, you can use this to measure the current across the circuit rather than checking the brightness of the bulb. If a DIY battery is used, the bulb may not light up at all, but you will see a current flowing as measuring using the ammeter.  

 

Part III - Modelling Particle Transfer
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Please make sure you read our safety notice prior to starting any investigations. 

This optional group exercise is designed to model the use of polymers in solid batteries, which are designed to be safer than the current liquid-based lithium-ion batteries commonly used.

In solid batteries with polymers (plastics) conducting the lithium ions (charged particles), the backbone of the polymer must be the correct size to easily hold onto and carry the lithium ion, shown here by the tweezers/tongs needing to match the size of the ball. If there are more polymers to transport the lithium, or they are closer together, the lithium ions are more easily transported in the battery, as shown by the distance between throwers/catchers. 

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You will need: 

  • A small ball (about the size of a ping pong ball)

  • A marble (optional)

  • A soft ball (e.g. a tennis ball or sponge ball)  

  • Large tweezers or chopsticks 

  • Barbecue tongs or similar (you could use two rulers instead) 

  1. Stand in a long line, spaced apart so that you can pass the small ball easily with your hands.  

  1. Try to pass the small ball from one end of the line to the other only using the tweezers.

  1. Repeat passing the small ball but this time using the tongs. Which one is more reliable? Did you drop the ball more often with one of the tools? Would this be the same with a different sized ball?  

  1. Now use the soft ball and throw the ball from one person to the next person until you reach the end of the line.
  1. Repeat passing the ball, but only allowing every other person to throw/catch (so one person in the middle is missed out).
  1. Repeat passing the ball, but only allowing every third person to throw/catch (so the ball is thrown over two people). Which way is more reliable? Did you drop the ball more often with one way?

 

Let's discuss!

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Here are some of the questions/further investigations you may like to explore:

In Part 1A...

1. Would adding more cells (more layers of coin, paper towel, foil) result in a higher or lower voltage? 

2. Why is it useful to splay/spread the wire when attaching it to the bulb or battery?

3. How does changing the numbers of layers affect the brightness of the bulb?

4. How does substituting paper or cardboard for paper towel affect the voltage? Is there a difference when using different thicknesses of cardboard? 

 

In Part 1B...

1. How does changing the number of ice cube tray cells affect the brightness of the bulb? 

2. What happens if you change the metal of the screws or the wires used? 

3. What happens if you mix the types of metal of the screws used? 

 

For both batteries...

1. If you are able to source an additional bulb, can you find a way to get both bulbs to light at the same time? What changes did you have to make? 

2. Can you find a way to light the bulbs alternately? What changes did you have to make? 

 

1. What happened to the bulb when you placed the electrodes on opposite sides of the jug filled with tap water? 

2. What happened to the bulb when you added a teaspoon of salt to the water? 

3. How did varying the amount of dissolved salt change the brightness of the bulb or the current you measured using the ammeter? 

4. What would happen if you first used boiled water? or filtered water? or boiled and filtered water? or water from different parts of the country/world (e.g. different bottled spring water)?

5. Does starting with vinegar make a difference? 

6. Are there other household liquids you could try? What about fruit juice? 

 

1. Which method, tongs or tweezers, was most reliable in passing the small ball (with which tool, tongs or tweezers, did you drop the small ball most often)?

2. Does your answer to 1. change when you use a different size ball, such as a marble or a tennis ball?

3. Which method of passing (next door, next door but one, next door but two) was the most reliable way of ensuring the soft ball reached the end of the line? 

4. Which method of passing (next door, next door but one, next door but two) was the fastest way of ensuring the soft ball reached the end of the line? 

5. Why is this activity a good model for particle transfer in batteries? Why is is a poor model? How could you improve it? 

 

We've posed lots of questions above and we'd love to hear your thoughts and findings. You can post your answers/ questions / comments below. You can add them at any time.  

 

We’ll be hosting three LIVE Q&A events where members of the Oxford Chemistry team behind the Power UP! resources will be answering your questions/comments. Check out our 'Welcome' page for dates and times. 

https://app.sli.do/event/sldrzti4

Celebrate!