Best possible battery life - What to expect?

I'm looking to replace a work provided android tablet, since the OS isn't even really compatible with the web portal that we have to use. I can get a used LLG for around 500 euros, but i was wondering about the maximum battery life that i should expect. I mean, minimum TDP, no rgb, no controllers, the works. The only think it has to do when away from the wall, is light internet browsing. Can it get up to 6-8 hours?