I bought two iPhone 6S Plus phones from Gazelle. Both needed new batteries within 90 days. With many sellers of used iPhones, a new battery is part if their refurbished phones. Not so with Gazelle.
The worst part is when I sent them a request regarding this through their website, I never got a response. They could have replied and said " we don't do batteries" but instead I got NOTHING for a response. Piss poor customer service.