I read the battery guide, very useful indeed Now I have a question: those batteries (specially polarcell and scud) are so good considering other parameters more than the capacity? I'm speaking of things like overheat, durability, possibilities of damaging the device after long usage. Since they are not original products I'm a bit scared of; you know, now I got two batteries and to be sure of getting a genuine Nokia BL-5j, I buyed a broken 5230 on ebay