Review on High Performance 5100MAh/39Wh/7.6V A1465 A1370 Battery For Apple MacBook Air 11" Mid 2011-2017 Years - NinjaBatt by Brian Edwards

The battery was easy to install using the included tools and worked great. I could use my MacBook again for hours! But 10 months later and it only lasts 20 minutes now. They offered a 1 year warranty, so I have emailed the vendor twice - but no response. Customer service phone number rings busy constantly. I noticed they "no longer sell" this item but instead sell the same thing but with a slight change in the wording. Hope that's not to avoid returns/warranty service.