Navarro,+N.

Natalie Navarro

November 11, 2011

Period 4

__4 Page Science Project Report__

A battery is one or more electrochemical cells that make stored chemical energy into electrical energy. Zinc- air batteries are electro-chemical batteries and are powered by oxidizing zinc with oxygen. Zinc- carbon batteries are packaged in zinc can that serves as both a container and negative terminal. The first battery had zinc metal as the anode and copper metal as the cathode. Other batteries that incorporate zinc include: zinc-mercury oxide batteries, commonly used in hearing aids, and the silver-zinc batteries, usually reserved for aeronautical applications.

All batteries have three same components: the anode, the cathode, and an electrolyte. The anode supplies electrons to the cathode and results in imbalance of electrodes which is corrected by the electrolyte by allowing negative particles to flow to the anode and positive particles to flow to the cathode.

Every single process that happens in a battery is a chemical reaction. Primary and secondary are types of batteries. Wet, dry, molten, and reserve are all types of battery cells. A battery’s capacity is all the electric charge it can hold. The more electrolyte and electrode, the more capacity.

Explosions, leakage, environmental concerns, and ingestion all are dangerous if occur with batteries. Explosions can occur by the misuse or malfunction of the battery. When a battery is recharged at an unusual rate, an explosive gas of hydrogen and oxygen is produced faster than it can escape through the walls of the battery, which makes pressure build-up and the possibility of explosion. Many chemicals in batteries are explosive, corrosive, or both. If there is a leakage, these chemicals can be dangerous. An environmental concern is the widespread use of batteries which can lead to toxic metal pollution. Ingestion is that small button/disk batteries can be swallowed if swallowed it leads to many health problems and rarely but sometimes causes death.

Primary batteries are batteries that cannot be used more than once. Secondary batteries are rechargeable. The chemical reactions in a primary battery are not easily reversible therefore reject to recharge primary cells. Secondary batteries can be recharged because when you apply an electric current, it reverses the chemical reactions during its use.

Battery recycling is an activity that is meant to reduce the number of batteries being disposed as solid waste. Batteries contain lots of chemicals and metals, their dumping may lead to water pollution and soil contamination.

An AA battery is the regular size of a battery. Batteries that are this size are usually used in electronic devices. An AA battery contains a single electrochemical cell. The capacity depends on the cell chemistry.

Battery life can be extended by keeping the battery in low temperatures such as a refrigerator or freezer. It slows the chemical reactions in the battery. The charge of secondary batteries can be extended form several days to a few months.

Batteries are be made of several things. Some of these include: magnesium dioxide, graphite, electrolytes, and zinc oxide.

A battery management system [BMS] is any electronic system, it manages many details including: monitoring its state, calculating secondary data, reporting that data, protecting the battery, controlling its environment, and/or balancing it.

A BMS monitors the state with many different contents: voltage, temperature, state of charge or depth of discharge, state of health, coolant flow, and current. It calculates value based on: maximum charge limit as a charge current limit [CCL], maximum discharge current limit as discharge current limit [DCL], energy since last charge or charge cycle, total energy delivered since first use, and total operating time since first use. A BMS protects its battery by preventing it from operating outside of a safe operating area such as: over-current, over-voltage [during charging], under voltage [during discharge], over temperature, under temperature, and over pressure.

The cell balancing principle states that battery pack cells are balanced when all cells in the battery pack meet two conditions: 1. If all cells have the same capacity, then they are balanced when they have the same State of Charge [SOC]. 2. If the cells have different capacities, they are also considered balanced with the same SOC.

Zinc- air batteries have some properties of fuel cells as well as batteries: the zinc is the fuel, the reaction rate can be controlled by varying the air flow, and oxidized zinc/electrolyte can be replaced with fresh paste.

Chemical reactions inside the battery are driven by either voltage or temperature. The hotter the battery the faster the chemical reactions occur.

Batteries consist of voltaic cells; each voltaic cell has two-half cells. One half-cell has an electromotive force determined by its ability to drive electric current to the outside of the wall.

A wet cell battery has a liquid electrolyte. A dry cell has the electrolyte immobilized as paste. A molten salt battery has molten salt as its electrolyte. Lastly, a reserve battery can be stored for a long period of time and is activated when its internal parts are assembled.

A battery’s characteristics can vary over load cycle, over charge cycle, and over lifetime due to various factors that include: internal chemistry, current drain, and temperature.

Electrochemical cells are a device capable of either obtaining electrical energy from chemical reactions, or make easier chemical reactions through the introduction of electrical energy.

Some types of primary cells are: Alkaline, Aluminum, Atomic, Bunsen, Chromic acid, Clark, Daniell, Dry, and many more.

Some types of secondary cells are: Flow, Fuel, Lead-acid, Deep cycle, Lithium air, and many more too.

Alessandro Volta created the first battery in Italy, 1800. The battery made by Volta was considered the first electrochemical cell. It consists of two electrodes: one made of zinc and the other was made of copper.

__Science Project__- __**Project 1: **__ __Problem statement:__ Which battery, Energizer, Duracell, or Rayovac, lasts the longest? __Hypothsis:__ If Energizer, Duracell, and Rayovac are being tested to see which lasts the longest, then Duracell will last the longest. __Independent Varible:__ Brand of battery __Dependent Variable:__ Amount of time battery lasted __Controlled Variables:__ device batteries used in, size of battery, type of battery, amount of batteries device holds, and battery power started with __ Data: __ __Results:__ In trial 1, the Energizer battery took 8 hours and 56 minutes. The Duracell battery took 8 hours and the Rayovac battery lasted 9 hours and 4 minutes. In trial 2, the Energizer battery lasted 9 hours. The Duracell battery lasted 7 hours and 46 minutes and the Rayovac battery lasted5 hours nand 5 minutes. In trial 3, the Energizer battery lasted 9 hours and 4 minutes. The Duracell battery lasted 7 hours and 51 minutes and the Rayovac battery lasted 5 hours and 9 minutes. The averages were 9 hours and 2 minutes for Energizer, 7 hours and 58 minutes for Duracell, and 5 hours and 1 minute for Rayovac. __Conclusions:__ My hypothesis was incorrect, I thought Duracell would last the longest and Energizer did. Energizer did best, Duracell got second, and Rayovac did worst. Each battery was about 1 hour or/and a half away from each other.
 * >  || Trial 1 ||> Trial 2 ||> Trial 3 || Average ||
 * > Energizer ||> 8 hrs 56 m ||> 9 hrs ||> 9 hrs 4 m || 9 hrs 2 m ||
 * > Duracell ||> 8 hrs ||> 7 hrs 46 m ||> 7 hrs 51 m || 7 hrs 58 m ||
 * Rayovac || 4 hrs 57 m || 5 hrs 5 m || 5 hrs 9 m || 5 hrs 1 m ||



__ Problem statement: __ Which type of battery, rechargeable or non-rechargeable, lasts longer? __ Hypothesis: __ If rechargeable and non-rechargeable batteries are being tested to see which lasts longer, then rechargeable batteries will last longer. __ Independent Varible: __ type of battery (rechargeable or non-rechargeable) __ Dependent Variable: __ Amount of time battery lasted __Controlled Varibles:__ device, size of battery, amount of batteries, brand of battery, and type of battery (zinc or copper) __ Data: __ __ Results: __ In trial 1, the rechargeable battery lasted 6 hours and 16 minutes and the non-rechargeable battery lasted 6 hours and 12 minutes. In trial 2, the rechargeable battery lasted 6 hours and 14 minutes and the non-rechargeable battery lasted 6 hours. In trial 3, the rechargeable battery lasted 6 hours and 7 minutes and the non-rechargeable battery lasted 6 hours and 15 minutes. The averages were 6 hours and 12 minutes for the rechargeable battery and 6 hours and 9 minutes for the non-rechargeable battery.
 * __ Project 2: __**
 * || Trial 1 || Trial 2 || Trial 3 || Average ||
 * Rechargeable || 6 hrs 16 m || 6 hrs 14 m || 6 hrs 7 m || 6 hrs 12 m ||
 * Non-rechargeable || 6 hrs 12 m || 6 hrs || 6 hrs 15 m || 6 hrs 9 m ||

__ Conclusions: __ My hypothesis was correct. I gathered two rechargeable Energizer batteries (without recharging them) and two non-rechargeable Energizer batteriesand the rechargeable batteries lasted longer but onlyy by a few minutes.



Problem statement: Does temperature affect how long a battery lasts? Hypothesis: If batteries at different temperatures are being tested to see which lasts longest, then the coldest battery will lasts the longest. Independent Variable: Temperature of battery Dependent Variable: Amount of time battery lasted Controlled Variables: device, type of battery, brand of battery, amount of batteries, and size of battery Data:
 * __ Project 3: __**

22m || 2hrs 11m || 2hrs 16m || 2hrs 19m || 19m || 2hrs 31m || 2hrs 26m || 39m || 1hr 35m || 1hr 41m || 1hr 38m || Results: In trial 1, the 25F battery lasted 2 hours and 22 minutes, the 75F battery lasted 2 hours and 28 minutes, and the 85F battery lasted 1 hour and 39 minutes. In trial 2, the 25F battery lasted 2 hours and 11 minutes, the 75F battery lasted 2 hours and 19 minutes, and the 85F battery lasted 1 hour and 35 minutes. In trial 3, the 25F battery lasted 2 hours and 16 minutes, the 75F battery lasted 2 hours and 31 minutes, and the 85F battery lasted 1 hour and 38 minutes. The average for the 25F was 2 hours and 19 minutes, for the 75F battery it was 2 hours and 26 minutes, and for the 85F battery it was 1 hour and 38 minutes.
 * || Trial 1 || Trial 2 || Trial 3 || Average ||
 * 25 F || 2hrs
 * 75 F || 2hrs 28m || 2hrs
 * 85 F || 1hr

Conclusions: My hypothesis was incorrect, I thought the 25F battery would last the longest. It didn't, the 75F battery did. The 25F battery was in second place and the 85F battery did the worst.



Home work assignment

 Lesson 1 is mostly about the Scientific Method. It talks about all the Processes of Science. In the Processes of Science the steps are observing, inferring, predicting, classifying, making models, evaluating, and conducting scientific investigations. These steps help you understand a scientific investigation better. When observing, your observations can either be qualitative or quantitative. Inferring and predicting are similar. Only that predictions are comments or claims about the future, while inferring has to do with something that happened or is happening. Classifying is the grouping together of items that are alike in some ways. Making models can help you to better understand or share the information. Evaluating involves comparing observations and data to reach a conclusion about them. A scientific investigation is the way in which scientists study the real world. Lesson 1 teaches us that while conducting a scientific investigation, there are many things we must do. Scientists gather information and explore the natural world while using different science processes. Science is basically a continuous cycle of asking questions. Scientists are always investigating and like in lesson 1 they have to use all or most processes to come to a conclusion. When observing, inferring, predicting, classifying, making models evaluating, and conducting scientific investigations you must be careful to record your data correctly, because if recorded wrong then your whole conclusion would be wrong then you would have to conduct the whole investigation again. Lesson 1 helps us better understand the Scientific Method too. The Processes of Science teaches how to conduct a scientific investigation correctly.

== I LOVE soccer, the Hunger Games [by Suzzane Collins], Busch Gardens, the color blue, and my friends and family. My favorite subjects are science and geography beacause they are interesting. My least favorite subject is math because I think it is boring!!! In science I like learning about weather, space, and the human body. I dislike simple machines and rocks. ==