Bought it a month ago, almost used every 2nd day, here’s the review.
Backup and Charging:
1) Charging Time: 8-10hrs, may increase with time with normal wear and tear as with every product.
a) Runs for 30-35 Minutes, even more, on a single charge, One charge is basically enough for 10days!
2) Trimming, Styling hardly takes 2-3minutes, So one charge is more than sufficient for your needs, Hence, battery backup should not be an issue, charge once a week, and it will go fine for years.
3) All those saying it isn’t corded, It’s for your own good, Imagine the risk of getting an electric shock while trimming your beard, You won’t want that, Right? And you will also not run it for whole 35-40 minutes at one go. Maximum 5 minutes is what you’ll run it, hence, backup is more then Enough.