| 12 | | Batteries can be made from a wide variety of chemical reactions. You can make a battery yourself using a [http://www.wikihow.com/Create-a-Potato-Battery potato] or a [https://www.scientificamerican.com/article/generate-electricity-with-a-lemon-battery/ lemon]. Common commercial batteries include carbon-zinc, alkaline, lithium, and lead-acid. Because they are chemical devices, batteries vary widely in size, capacity, and characteristics. In general, the larger the battery, the more chemicals it contains and the more electrical energy it can generate through the chemical reactions. |
| | 12 | Batteries can be made from a wide variety of chemical reactions. You can make a battery yourself using a [http://www.wikihow.com/Create-a-Potato-Battery potato] or a [https://www.scientificamerican.com/article/generate-electricity-with-a-lemon-battery/ lemon]. There are two main types of batteries: |
| | 13 | * Primary: disposable batteries that you throw away when their chemicals have fully reacted and can't make electrons flow anymore (battery is fully discharged) |
| | 14 | * Secondary: rechargeable batteries where if you force current to flow through the battery in the reverse direction after the battery is discharged, the chemical reactions reverse themselves (the battery is re-charged) so it can make electricity flow again. |
| | 15 | Common commercial batteries include different chemical compositions: carbon-zinc, alkaline, lithium, lead-acid, etc. and different sizes including: [https://en.wikipedia.org/wiki/AA_battery AA/penlight], [https://en.wikipedia.org/wiki/D_battery D/flashlight], [https://en.wikipedia.org/wiki/Nine-volt_battery 9V/radio], [https://en.wikipedia.org/wiki/Lantern_battery 6V/lantern], and a wide range of custom sizes. Batteries vary widely in size, capacity, and characteristics. In general, the larger the battery, the more chemicals it contains and the more electrical energy it can generate through the chemical reactions. The chemistry and construction determine whether the battery is disposable or rechargeable. |
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| | 17 | FRC competition robots use large re-chargeable [http://www.andymark.com/power-patrol-sla1116-12-volt-18ah-batteries-2-pack-p/am-3062.htm lead-acid batteries]. Team 2537 also uses [http://www.batterysharks.com/12-Volt-7-Amp-Sealed-Lead-Acid-Battery-p/12V-7AH_B12-7.htm smaller lead-acid batteries] to power lighter duty robots like peanut bots. All of these batteries are sealed so the acid/electrolyte doesn't get out and are called Sealed Lead Acid (or SLA) batteries; they also store a lot of energy and should be treated with respect. |
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