Some tech jargons never change with time..

How many years have mobile phones been in the market? Decades and how many phones have you changed since you started using handphone? Each time you bought a phone since then, you are most probably been advice to have your battery to be charged for full 8 hours! And that recommendation stays. Having said that, does that me the is no improvement on the power element? I don't so. The phone dealers never change their scripts since day one mobile phone hit the market!