This is a brand new Dell 71JF4 battery. The superior South Korean cells inside the battery cartridge will provide longer run times between charges as well as a longer service life than cheaper batteries.

We use the highest quality lithium-polymer battery cells and components that charge faster, last longer and weigh less than cheaper, lower quality batteries. Lower quality batteries can wear out in just a few months. Our batteries can last up to 5 years.

This means you can recharge your laptop any time without diminishing your battery capacity. This Dell 71JF4 battery replacement is 100% compatible with your Dell laptop and each battery is individually tested before shipment and backed by 30 day complete satisfaction guarantee and a 2 Year warranty.

You can expect about 2 hours to 4-1/2 hours of run time with this Dell Inspiron 15 7557 battery when new, depending on your energy use.