How to get one specifically designed for my laptop

Question:I think all laptop battery interchangeable between brands, or are they brand-specific?But, how about mobile chargers too, should I get one specifically designed for my laptop, or will any one do? Answer:All batteries are brand specific, most are even series specific, so a compaq battery won't work in every single compaq laptop. Chargers are also brand/series specific, but the difference in chargers is less than that of batteries (A good deal of the time, the only difference between the chargers of different brands are the connector). Because of that there are a few chargers that work on different brands.You'd better buy same model with you battery.For example this one:http://www.new-laptop-battery.com/ And you can choose this battery : ASUS A3 battery , ASUS A3000 battery , ASUS A4000 battery , ASUS A8 battery , ASUS A9 battery , ASUS F8 battery,Dell 1691P battery , Dell G5266 battery , Dell Inspiron 9400 battery , Dell U4873 battery. I believe this is best !Good luck !