sábado, 18 de fevereiro de 2017

How to save your Battery

How to save your battery.

Charging overnight won't degrade really. But charging while using the phone surely will.

Every rechargeable battery has certain number of charge discharge cycles which is specific to its capacity (current output or voltage).

The Basis for charge discharge cycles is the Reversible reaction occurring in the battery.
  • (Li+ + e- → ← Li-) ( → Charge ; ← Discharge)
Excessive charging will not help, in the other way it corrodes the electrode enhances the degradation rate of the electrolyte.

So, here's my suggestion - Use your phone from 100% to 5% and only then leave it for charging.

Don't take it to 40% and put it on charge and still keep using it. Battery temperatures can reach around 40°C while you're using your phone with the charger plugged in and that's not good for you battery life.

There are two main types: Lithium ion and Lithium polymer, both are having different chemistries and they are not same. Lithium polymer is light weight and can have more Coulombs* ratings, which means capable of giving more current than lithium ion. Lithium polymer is less likely to die quickly than lithium ion by over charging. But still both lithium ion and lithium polymer can be over charged by leaving charger on.
  • 1C = 1A ⋅ 1s
  • * The coulomb (unit symbol: C) is the International System of Units (SI) unit of electric charge. It is the charge (symbol: Q or q) transported by a constant current of one ampere (A) in one second (s):
Also turn brightness down, remove from your device unneeded apps and emails, check which apps consume most battery or are get alerts, and in areas of bad reception do a network reset. A lot of battery life especially on iPhones are due to bad upgrade and apps in the background using your resources.

  1. Don't use your phone while charging.
  2. Leaving it to charge all night is fine, given that you're following the rule above.
  3. Charge phone only when it is under 5% capacity
  4. Check what is running on your device.

quarta-feira, 15 de fevereiro de 2017

Ubuntu 14.04.5 with Epson L455

So this is log about my experience with Epson L455 multifunction printer that I bought in Brazil.

Does it work?

Short answer: YES!

Not only I did setup the printer using only a Linux station with a Mozilla/Firefox browser, but I believe the information on the WEB and also on the "quick start sheet" that comes with the printer (in the box) it not clear about this.  You do not need to use CD/DVD or the other paid OS.

Does EPSON support Linux ?

For my surprise and exactly what made me choose the EPSON printer was that it is really committed to support GNU/Linux users.

Check this (and choose Linux OS):

Does EPSON have good documentation to support Linux, see this:

And I notice support for not only Ubuntu 14.04 and 16.04 but for other flavors of Linux as well.

Does EPSON L455 scanner and printer work over wifi without the need of a USB network host computer ?

YES!  But you need to install all the packages as describe in the documentation you downloaded, and also configure properly the network, printer CUPS and SANE conf file (all detailed in the documentation).

In less then 30 minutes I figured out (ie. followed the instructions) and was not only printing with quality control but also: scanning documents and changing the network DHCP IP to a fixed IP address using just the a web browser connected to the printer WEB-GUI.  And also, don't forget to change the Admin password!

Does it work with Android, to print and scan direct to and from your phone ?

YES!  But you need to download and configure from Google Play the EPSON iPrint app.  Should work with iPhone too.

Final words:  


GNU/Linux community loves you!