| As of the date of this writing there were 19,300,000 | | | | - Nominal Voltage - is battery voltage range 3.7V, |
| results in a Google search for the keyword laptop | | | | 5.2V, 10.2V, 12V etc that says that a voltage range |
| battery. On the one hand that is great if you are in | | | | exists depending on the number of cells in the |
| need of one but at the same time overwhelming. | | | | battery. For example a 12 Volt battery is made of 6 |
| How do you know what to buy, from who to buy, | | | | cells and has a Float voltage of about 12V. |
| and what you even should be looking for when | | | | - Charge Voltage - The voltage of a battery while |
| buying a laptop battery? I have identified seven | | | | charging. |
| categories a person needs to be informed about | | | | - Discharge Voltage - The voltage of a battery while |
| when going out to make a purchase for a new | | | | discharging. Again, this voltage is determined by the |
| battery and they include: Part number, Make, and | | | | charge state and the current flowing in the battery. |
| Model; and Chemistry; and Capacity; and Voltage; and | | | | For laptop batteries the most common voltage |
| Watt Hours; and Number of Cells; and finally the | | | | measurements are: 7.2V, 9.6V, 10.8V, 11.1V, and |
| Retailer, Price and Warranty. | | | | 14.4V. Since you cannot choose the voltage |
| Part Number, Make, and Model | | | | measurement for your laptop go with whatever |
| Essential to the purchase of your new laptop battery | | | | measurement is closest to your original battery. |
| is the part number. A part number is a unique | | | | Remember nominal voltage allows for slight deviation |
| identifier that is assigned to a part to simplify | | | | from the original but you cannot use a 7.2V battery if |
| referencing and to unambiguously define a part within | | | | it requires 14.4V. The best example would be a 10.8V |
| a single manufacturer. The part number above all is | | | | battery could be used with an 11.1V battery. |
| what needs to be known before going to buy your | | | | Watt Hours |
| battery. Secondly the make and model are next | | | | Whr, Watts, Volts and Amperes are basic units of |
| most important part identifiers you must know. The | | | | measure for a DC (Direct current) power supply. A |
| make is the manufacturer (e.g. Sony, HP, Dell). The | | | | battery, for example, is a direct current power |
| model is a multi-component word that includes the | | | | supply and the combined measure Volts x Amps = |
| line and actually model number. For example the Sony | | | | Watts. Watts are important because watts |
| VAIO VGN-FZ90S is an example of a Sony made | | | | represent the electrical energy spent by a battery |
| laptop that is part of the VAIO series and which has | | | | (power generator) and used by an electrical device. |
| model number VGN-FZ90S. | | | | Watts in effect is the measure of the amount of |
| Most laptop's hold this information within your | | | | work done by a certain amperage (amount) of |
| computer's system info. To access this info go into | | | | electric current at a certain pressure or voltage. Watt |
| the properties of your computer and view the model | | | | hours are measured by multiplying volts and capacity |
| information. The battery's part number can be found | | | | together (and commonly rounding up). |
| on the battery itself. | | | | Number of Cells |
| Chemistry | | | | The number of cells is important since the more cells |
| Most laptops now require a lithium based battery | | | | contained in the battery the higher the capacity will |
| chemistry. You cannot choose your chemistry type | | | | be. To determine the number of cells in your laptop |
| for most batteries. It is still good however to know | | | | battery you need to have some general idea of |
| which chemistry type yur battery requires. | | | | what cells are being used in your battery. The most |
| Capacity | | | | common battery cell is the 18650 and is |
| Capacity also known as runtime Battery capacity | | | | manufactured by LG, Sony, Sanyo, Samsung, |
| quantifies the total amount of energy stored within a | | | | Panasonic and many others. The 18650 is a 3.6V |
| battery. More capacity equals a longer runtime | | | | cylindrical Li-Ion cell. 18650 has no memory effect |
| between battery charges. Battery capacity is | | | | (distinguish between digital memory effect) and |
| measured in amperes, which is the volume of | | | | longer storage life than NiMH battery cells. 18650 is |
| electrons passing through the batteries electrolyte | | | | light weight and has a high energy density. It is in |
| per second. A milliAmp hour (mAh) is the most | | | | effect perfect for building batteries for laptop and |
| commonly used notation system for consumer | | | | other portable power devices. |
| electronic batteries. Note that 1000 mAh is the same | | | | Specifically the 18650 battery cell has a nominal |
| as 1 Ah. | | | | voltage average of 3.7 V. It has a nominal capacity |
| When buying a battery knowing how much capacity | | | | of 2200 mAh. It has a maximum charge current of |
| you may need depends on: how much you want to | | | | 2.4 Ah and a max discharging current of 4.6 Ah. Its |
| spend, how often and how long you use your laptop | | | | dimensions (DxH) are 18.3 mm (Max 18.4) x 64.9 mm |
| on battery power, and what applications you my be | | | | (Max 65.1). It weighs 46.5 g (1.64 oz). It has cell cycle |
| running off the battery's power. The higher the | | | | performance of 80% of initial capacity at 300 cycles. |
| capacity the more money you will spend, so if you | | | | All in all the 18650 is a very good battery cell. |
| need the longer runtime's or you use applications that | | | | Using this common laptop battery cell as our base |
| require more battery juice then buy the higher | | | | you can determine the number of cells in your laptop |
| capacity. If the | | | | battery by doing the following. Divide the battery's |
| Voltage | | | | stated voltage by the 18650's nominal voltage to get |
| Volts - or V - is an electrical measurement of energy | | | | the number of cells in series and divide the battery's |
| potential. Mathematically voltage is commonly | | | | stated capacity by the 18650's nominal capacity to |
| measured by V= I x R; where V=Voltage, I=Current, | | | | get the number of cells in parallel. Then multiply the |
| R=Resistance. Voltage can also be defined as | | | | results of the series and the parallel to get the total |
| Electrical Potential difference - a quantity in physics | | | | number of cells in the battery. |
| related to the amount of energy that would be | | | | Retailer, Price and Warranty |
| required to move an object from one place to | | | | Once you have all the above information now it is |
| another against various types of force. In the fields | | | | time to pick and choose a retailer to buy from. When |
| of electronics the electrical potential difference is the | | | | choosing a retailer to buy a laptop battery from take |
| amount of work per charge needed to move electric | | | | into consideration the retailer's reputation, the price, |
| charge from the second point to the first, or | | | | the warranty, and the return policy. Be sure to chat |
| equivalently, the amount of work that unit charge | | | | or speak with one of their representatives if you |
| flowing from the first point to the second can | | | | have questions. Be smart about where you buy from |
| perform. A battery contains four unique types of | | | | and only buy from a reputable retailer. With batteries |
| voltage measurements. Each voltage measurement | | | | you never want used and you always want to be |
| type residing in a battery effects battery life. | | | | sure that is a problem arises the retailer will be there |
| - Float Voltage - is battery voltage at zero current | | | | to make it right. |
| (with battery disconnected). | | | | |