Consider the volts & amps in terms of water tap (valve).
When a tap (valve) is opened on half way, the water that flows from the pipe produces a certain amount of pressure. When you opened the tap (valve) fully, at that time the water produces more pressure in the pipe. This pressure, or power, is same as like to the volts a battery utilizes. If a laptop is running not more memory consumption programs, less power is needed to discharge energy into a laptop. Though, if a laptop is running a .vob files (i.e.) the dvd film files or other large energy consumption applications, additional power will be needed to discharge the essential amount of energy to run the dvd film.

You may also note that increasing the size of the pipe which is coming to the tap and as a result the tap (valve) will not produce a different result, when you opened the tap you seen the same result of water flow from the tap. This is an illustration of the quantity of resistance in the flow of energy. Calculating this resistance is calculated in terms of amps. In terms of a battery, the sum of resistance is dependent relative on the size of the battery & the sum of energy inside.

• A Few Things to think over in Battery Life:

Have in mind that technology continuously changing in the modern era. Your old battery may be ranking in a lower run time than a newer one for the reason that technological advancements that have created longer lasting batteries. In addition, your laptop battery's run time depends on the programs you utilize. Some of the programs need more energy to run than the other ones.
Few Examples are here: the screen (in particular the brightness setting is high), hard disk drives, CD & DVD drives, & wireless network cards. Unluckily, there is no specific answer to the question, how long accurately will my laptop battery last long? The important factor is how & what you make use of your laptop for. There is one way for preserving power is to go to your Power Management settings icon in the Control Panel option.
You can switch off settings or programs you do not use. In addition think about your brightness of your screen & close and exit your wireless card when you don't want it.