The battery life is still pretty great on it after a year and a half or so of use. I once took it on a family vacation and blazed through Trotsky's History of the Russian Revolution
for several hours a day for a week, never had to charge the eReader once. I may be remembering wrong but I think the battery is replaceable if needed, there's no glue or shit like on the Kindles.
A radical bookstore is a bookstore specializing in radical left / socialist books. Look for independent bookstores in your city and radical bookstores should be on the list if you have one nearby. Typically they'll be cash only. Anarchist bookstores are more common than Marxist / "authleft". Besides buying books, radical bookstores are a good place to socialize and learn which events are happening in your area without the sectarian spin. http://www.maydaybookstore.org/
Mayday Books is my specific example, I don't think I'm doxxing myself too bad.