Dell 0991XP | 4-Cell 40WHr Battery for Inspiron 5558

Here are the technical specifications for the Dell 4-Cell 40WHr Battery for Inspiron 5558:

- Battery type: Lithium-ion
- Number of cells: 4
- Capacity: 40WHr
- Voltage: 14.8V
- Compatibility: Inspiron 5558
- Dimensions: 10.79 x 4.49 x 0.79 inches
- Weight: 9.6 ounces

Helpful notes:
1. This battery is a genuine Dell product and is designed specifically for the Inspiron 5558.
2. It has a decent capacity of 40WHr, which should provide a good amount of battery life.
3. Make sure to check the dimensions and compatibility before purchasing to ensure it will fit your laptop.