Understanding Laptop Batteries

Types of Laptop Batteries:

Nickel Cadmium (NiCd) Batteries: These were the first rechargeable batteries manufactured for laptops. They were relatively inexpensive, had high output and versatile, because they could be used in a wide variety of products. However, NiCd batteries have now been abandoned by laptop manufacturers with the introduction of more efficient and lighter-weight batteries.


Nickel Metal Hydride (NiMH) Batteries: NiMH was a big improvement concerning power output, reliability, cost, safety and capacity. The "memory effect" was the only issue with NiMH batteries which require them to be fully discharged before recharging to gain maximum output. These batteries can still be found in older model laptops.

Lithium Ion (LiON): This type of batteries has become the most popular for laptops since the “memory effect” has been eliminated, and much lighter than the other two in weight. However, the market price is also the highest.

Battery Cycle:

One battery cycle is used every time a battery is charged or discharged. Technically speaking, it is defined as the number of cycles a battery can perform before its nominal capacity falls below 80% of its initial rated capacity. Lifetimes of 500 to 1200 cycles are typical. For example, NiCad battery has a cycle life of 500-1000 or more cycles.

Battery Run-Time:
Battery run-time depends on a number of factors. Most of the time, it is the design of, and the power demands made by the machine that determines the actual battery run-time. For example, use of the screen, the hard drive and other accessories will significantly influence the duration of the run-time.

What are Smart and Dumb Laptop Batteries:
Some laptop batteries are equipped with internal microprocessor circuits that help manage battery energy, set the charger to the correct charge algorithm, predict running time, or according to Smart Battery System (SBS) forum, provide a state-of-charge (SoC) indication. These batteries are called “Smart” batteries. Those batteries termed as, “dumb” do not have these features, may be just counterparts, or may function to provide power only.

Optimizing Laptop Batteries:
1. “Condition” is a term for fully charging and discharging a new laptop battery to maximize performance and allow it to reach its maximum rated capacity. NiMH and NiCd batteries need to be conditioned at least once a month to reduce the “memory effect”.
2. Metal connecters should be cleaned occasionally to maintain good conductivity
3. Ensure that device's power management features in the BIOS and Operating System are optimized, turning off the screen, using speed step
4. Avoid leaving your laptop on overnight all the time while charging. The laptop should be turned off occasionally.
5. Store the battery in a cool, dry, clean place if you’re not going to use it for a month or longer.
6. Turn down the brightness of the LCD screen when watching a movie on our laptop. Decrypt DVD movies and store it on your hard disk drive to avoid constant use of the DVD drive which consumes a lot of power
7. Never expose your laptop battery to heat, moisture, short-circuit, drop or physically abuse it.