Where can I buy a cheap battery for my sony? is I have a laptop Sony VGP-BPS13A / S has already told me goodbye. I do not even 5 minutes is difficult. I looked on the official sony, but not available and the price seems excessive to me (60 €). A friend told me to take the opportunity to buy a battery that is better, but ... would be unofficial, right? ? Could use a better one? ? Could you suggest any site that is legit? I'm not an expert, so I come to you. I've seen some with 8 or 12 cells, with more power, etc ... What does this mean? ? Are they better? ? I can trust?