How to caculate your Dell battery run time

Take care of your Dell Laptop Battery and ensure that it will be ready to work properly when you need it most. Some general tips for laptop care include: avoid extreme temperatures, don't leave a laptop outside in cold weather or leave it in a hot car. Cold laptop battery can't create very much power and hot laptop batteries will discharge very quickly. Use electrical power when available to keep Dell battery charged. Don't let your laptop go for long periods of time without using the Dell laptop battery.
You may also want to know how to caculate your Dell battery run time. Laptop batteries have two main ratings on them: Volts and Amperes. Because size and weight of laptop batteries is limited when compared to larger batteries such as car batteries, most companies show their ratings with Volts and Milliamperes. One thousand Milliamperes equals 1 Ampere. When buying a laptop battery, select batteries with the most Milliamperes (or mAh). Batteries are also rated by Watt-Hours, perhaps the simplest rating of all. This is found by multiplying the Volts and the Amperes together. For example:
14.4 Volts, 4000mAh (Note: 4000mAh is equal to 4.0 Amperes).
14.4 x 4.0 = 57.60 Watt-Hours
Watt-Hours signifies the energy needed to power one watt for one hour. This laptop battery can power 57.60 watts for one hour. If your laptop runs at 20.50 watts, as an example, this Dell Laptop Battery could power your laptop for 2.8 hours.
Laptop batteries have finite life spans. Whether you use the power cord and remove the battery it will lengthen the life of the Dell battery. Li-Ion laptop battery lifespan is approximately 1000 charge cycles, or 2-4 years under normal operating conditions.
Keeping the Dell battery in a cool place can prolong its life but not in a period of extended storage. The Li-ion battery should be stored at 40 percent rather than full-charge state.
The battery ages even if not used. For best results, keep the Dell battery cool. In addition, store the battery at a 40 percent charge level. Never fully charge or discharge the Dell laptop battery before storage. The 40 percent charge assures a stable condition even if self-discharge robs some of the battery's energy. If you are looking for other laptop accessories information, you can visit here: Compaq F4812A battery(14.8V )
Sony Vaio PCG-6C1N battery
Dell Latitude D620 Battery(4400mAh)
Dell D5318 Battery(Li-ion, 9 cells )
Dell Inspiron E1705 Battery(Li-ion, 9 cells )

What to do when over charge Dell battery

It may happened to you that you forget to turn off your laptop charger, when you charge your Dell battery, then you may want to know what to do when over charge your laptop battery.
First it's important to understand what overcharging is:
Over-charging occurs when the charger keeps the Dell battery at a temperature that is warm to touch (body temperature) while in ready condition.
Li-Ion laptop batteries have built-in controller chips which prevent it from overcharging, as they can explode if overcharged. Overcharging does not affect the life span other than potentially destroying the Dell Laptop Battery.
A lithium-based battery should never be allowed to get warm in a charger. If you have this happen, the laptop battery is no good or the charger is not working properly. Don't continue to use the battery or charger if this happens.
A Lithium-ion battery may be damaged by extensive overcharging (continuously on a charger for more than 24 hours). Damage to the Dell battery from overcharging would only occur in the very unlikely event of a malfunction of the charging system.
If your laptop battery life still isn't enough and you don't mind carrying the extra weight, bite the bullet and buy a spare. The fact that buying a new Dell battery isn't easy or cheap -- and that most people don't buy a laptop thinking they're going to have replace the battery after a year or two -- is to me evidence that batteries are the laptop industry's dirty little secret that they don't want us to think about too much. If you want to buy a new Dell battery, or other laptop accessories, here are some good choice: Dell D5318 Battery(Li-ion, 9 cells )
Dell Inspiron E1705 battery(Li-ion, 9 cells )
Sony Vaio PCG-6C1N battery(Li-ion )
Dell 312-0340 Battery(Li-ion, 9 cells )
Dell GD775 Battery(Li-ion )
Dell Latitude D620 Battery(4400mAh)