I recently bought this tenor 10.or E 32GB ROM, 3GB ram new branded smartphone which is launched in September 2017 marketed by Amazon India. This brand is very new in India. Inside the box I got the pin to insert sim, manual and charger. I liked the design, weight, video quality, sound quality etc. Call quality is important and I found it similar to Nokia call quality which is very famous for it. Audio sound is loud and very lear. Good thing is, we can get up to 4-5 days battery life even after using it for every day.
This is how I get 4-5 days battery life. I use the single sim. After setting display brightness to around 10%, using it for hotpost almost for 15 hours long per day, and for some call and app usage for around 15 to 30 minutes long in total, I get battery life for 1 full day! It means, if you are not a gamer and using a single sim, without much heavy usage, with battery saver turned on(which is in battery menu inside settings), you may end up getting battery life up to 5 days long easily. You can also save extra battery life by keeping’Background process limit" to"At most, 2 processes". For that you have to activate "developer mode" by going to "Settings", "About Phone", then by clicking "Build number" for 4 to 5 times.
You may find these settings in other smartphone too. try them. I hope this review is usuful for you anyway.