worst. its 2 cells.

sauce

Features & Specifications
Specifications for the Asus Eee 1002HA include Windows XP Home, SD card reader, 1GB of RAM, 160GB HDD, a 10-inch LCD with a resolution of 1024 x 600 and the CPU is an Intel Atom N270. The 1002HA weighs 2.6 pounds and is 1-inch thick. Rather than plastic like the majority of the Asus systems, the Asus Eee 1002HA is covered in brushed aluminum.
Asus also offers owners of the 1002HA 10GB of online storage and offers the Super Hybrid Engine that allows users to tune the system to save power or offer highest performance. The battery is a 2-cell unit with 4200mAh of power and the little machine has 802.11n Wi-Fi along with Bluetooth.

must be a 2-cell high capacity lithium polymer battery.
compared to a cheap & older technology 6/4 cells normal capacity battery.

theoretically this 2-cell is better and of course, lighter.


...........The small 2-cell battery that Asus ships with the 1002HA seems small at first glance, but offers good runtime. Using MobileMark 2007's reader benchmark gave a battery run time of 243 minutes (roughly 4 hours). That time was achieved with the LCD set to full brightness, Wi-Fi on and the Super Hybrid Engine set to auto mode for adjusting performance.............