In order to complete some electricity-battery experiments that I wanted to do with our study of Benjamin Franklin, I needed some supplies such as zinc and copper plates, a LCD watch, sound chip and a light bulb set-up. I priced the individual components and it was beginning to get more pricey than I wanted it to be. I then stumbled upon this Enviro-Battery science kit by Green Science. I normally don't purchase kits because I have found that they often provide little for their high price tags, but this kit seemed to have everything I wanted in it, and the price was reasonable (around $11, which was considerably less than the components cost if bought separately.)
Before starting in on the experiments, I reviewed with the boys from Real Science-4-Kids' Physics book how the electrons move and why copper and zinc plates are used in the demonstrations.
My original plan was to make a lemon battery, but the kit featured potatoes instead (although it says in their booklet that you can use lemons or apples.) The boys were more interested in using potatoes, and since we had them on hand, that is what we used. The instructions in the booklet were easy to follow and pretty fool-proof.
The end of the negative (black) wire attached to the LCD watch is threaded through the hole in one of the zinc plates and the end of the positive (red) wire attached to the LCD watch is threaded through the hole in one of the copper plates. Each plate is then inserted into a different potato. A second set of copper and zinc plates are connected to a separate wire, forming a "connection pair." These plates are then inserted into the potatoes, the zinc plate side going into the potato that has the copper plate in it from the watch, and the copper plate going into the potato that has the zinc plate in it from the watch.
Once these are inserted, the potatoes power the watch.
We initially had a little trouble getting the bulb to light. but then we remembered that water batteries do not work with distilled water because the battery needs the minerals in the water. We remedied the problem by adding about a tablespoon of vinegar to each of the bottles, which is suggested in the booklet as a way to experiment further with the kit. ("Try adding some vinegar to the solution. Does this make the LED brighter?") I must tell you, however, that the lamp provided in the kit is so small that it is hard to tell at first that the bulb is lit, one of the less-than-perfect aspects of the kit.
We also made a lemon battery to power a sound chip that came with the kit. The sound chip cannot be heard, however, unless it is put against your ear. This may be a plus for those not too wild about electronic sounds, however. The sound could be amplified with the aid of a paper cup (included in the kit), which was a great introduction to a sound unit.
For James' "final exam" to see if he understood how to put a battery together, had to construct one out of an apple, and he was able to do so without any help from me.
The kit's booklet also suggests making batteries from mud, and using paper clips and forks as electrodes, and the booklet suggests experimentation by mixing the different concepts.
All-in-all, I was very pleased with the kit and feel that the components will last quite a while for electricity experimentation for the boys. Alex also received the Weather Station from Green Science for Christmas and from what I can see, it looks to be as good as the Enviro-battery kit, but we are waiting for spring to crack it open as it has a "greenhouse effect" demonstration terrarium as the base for the weather station. If you are looking for low-cost materials for science experimentation, these kits might just be what you are looking for.
Disclaimer: I did not receive any compensation for this review. All opinions expressed are mine. I just liked this product and thought I would share it with you. I am disclosing this in accordance with the FTC regulations.
and you have a switch...
and sometimes it takes it when we don't want it to. 
but they use up the battery twice as fast. This is called a parallel circuit. 
How many paperclips will the magnet hold? 
Magnetize a paperclip... Does the paperclip thus treated pick up metal objects? Why?
Does a magnet pick up as many iron filings at its middle or at its ends? What does this show? 
Place iron filings on stiff paper. Pass a magnet underneath; what forms do the filings assume? Do they make a picture of the direction of the lines of force which come from the magnet? 
