Please ensure the product(s) that you are going to buy fits the brand, model and part number of your device.

Specifications:

Battery Type: Li-ion
Color:  black
Dimension:  267.8X49.4X21.85 mm
Capacity:  4400mAh
Volt:  14.8V
Replace battery part number: 
70-NA51B2100 70-NFH5B2000
70-NA51B3000 70-NDK1B1300
90-NA51B2000 90-NA51B2100
90-NA51B2200 90-NA52B2000
A42-A6  
 
This battery is also compatible with the following models : 
ASUS
ASUS A6J A6T A6R A6K A6V A6Je A6TCc A6Rp A6Jc A6Km A6Vm
ASUS A6Ja A6Va A6Ne A6 A6G A6Ga A6K A6L A6N A6Ne A6U A6V A6Va A6Vc A6Vc(Z9200Vc)
ASUS A6000 A6000G A6000Ga A6000K A6000L A6000N
ASUS A6000Ne A6000U A6000V A6000Va A6000Vc Series

Understanding your ASUS 70-NA51B2100 ASUS A6 A6G A6Ga A6K A6L battery  Needs

What is the run time of  ASUS 70-NA51B2100 ASUS A6 A6G A6Ga A6K A6L battery ?

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 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 laptop battery could power your laptop for 2.8 hours.

How can I maximize the performance of my ASUS 70-NA51B2100 ASUS A6 A6G A6Ga A6K A6L battery?

There are several steps you can take to help you get maximum performance from your laptop battery:

Prevent the Memory Effect - Keep the laptop battery healthy by fully charging and then fully discharging it at least once every two to three weeks. Exceptions to the rule are Li-Ion batteries which do not suffer from the memory effect.

Keep the laptop Batteries Clean - It’s a good idea to clean dirty battery contacts with a cotton swab and alcohol. This helps maintain a good connection between the battery and the portable device.

Exercise the Battery - Do not leave the battery dormant for long periods of time. We recommend using the battery at least once every two to three weeks. If a laptop battery has not been used for a long period of time, perform the new battery break in procedure described above.

Battery Storage - If you don’t plan on using the laptop battery for a month or more, store it in a clean, dry, cool place away from heat and metal objects. NiCad, NiMH and Li-Ion batteries will self-discharge during storage; remember to recharge the batteries before use.

Upgrade my ASUS 70-NA51B2100 ASUS A6 A6G A6Ga A6K A6L battery from NiMH to Li-Ion

NiCad, NiMH and Li-Ion laptop batteries are all fundamentally different from one another and cannot be substituted unless the laptop has been pre-configured from the manufacturer to accept more than one type of battery chemistry. Please refer to your manual to find out which rechargeable battery types the laptop device supports or use our Battery Finder above to find all the compatible laptop batteries for your device. It will automatically list all of the battery chemistries supported by your specific device. If your device does allow you to upgrade the battery from NiMH to Li-Ion, you will typically get longer run times.

For example, if your laptop uses a NI-MH battery that is 9.6 Volts, 4000mAh and the new li-ion laptop battery is 14.4 Volt, 3600mAh, then you will obtain longer run time with the li-ion battery.

Example.

Li-Ion: 14.4 Volts x 3.6 Amperes = 51.84 Watt Hours
Ni-MH: 9.6 Volts x 4 Amperes = 38.4 Watt Hours
The Li-Ion is stronger and has longer run time.