If that seller won't answer your question then you don't buy it. Here the battery prices have come down from what they were but in your case, it's that simple. You found a company that won't answer your concerns and as such know where not to buy such a part.
Bob
<span id="INSERTION_MARKER"> Hello, Following a message that appears when you turn on my computer and after a test Batterie Lenovo G570 I have to change it (my computer two years to the day). My concern is that I do not want to invest in a battery that will not be compatible or will eventually burn out my computer, I come to you to make my choice. On the internet I found this one which looks to me to match the one I currently

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic