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Fast charging and protecting your smart phone’s battery life.

Smart phone battery life

Do you want to charge your smart phone safely and keep the battery life good for as long as possible?
Are you surprised at how slowly your smart phone appears to charge sometimes?
Are you confused by the different cables and chargers around?

If you answered yes to just one of these, you’ve come to the right place…

Your smart phone’s Lithium-Ion battery is an incredibly sophisticated component that has evolved to supply reliable power for much of the day, safely, and for an extended lifetime of 1,000 charges. 

Over those 1,000 charges, your battery will start to deteriorate and not yield the life it had when it was new. 

A key way to reduce that degradation is NOT to charge it past 80-90% if you don’t have to and ideally keep it above 10-20%.  This may mean charging it twice daily to keep it in that range and skipping overnight charging to 100%. 

Like most people, you’ve probably got several chargers you’ve received with smart phone purchases over the years.  

If you’re still using the charger that came with a smartphone just a few years ago, you need to change it!

👈 If you are using one of these to charge your iPhone 8 onwards, it’s only providing between 18-30% of the power your smart phone needs.  

In other words, your smart phone could be charging up to five times slower than it’s capable of. 😳

Why Battery Size Matters

Smart phones now have 3-4X more battery capacity than just a decade ago. You may not have noticed the change as it has been a gradual change in line with smart phones getting thinner. While some of that capacity provides better battery life, more is used because smartphones now have giant screens and are more power-hungry. What could charge a smart phone a decade ago will only give you a fraction of the power needed now.
To understand if your smartphone is getting a meaningful charge, you should measure it in terms of the % battery boost in a particular timeframe, e.g. 0-50% battery in 30 minutes. 

Using an old charger with your new smartphone may take over 2 hours to get a meaningful charge. Of course, that’s not a lot of use when you’ve only got 10 minutes to get out of the house. 

So what’s the answer?

Faster charging.   The first iteration was QuickCharge from Qualcomm. This allowed slightly quicker charging using the micro-USB cable. However, it was proprietary and generally limited to specific Android devices that used Qualcomm components (by no means all).  Plus, it was limited to the inferior micro-USB cable, which breaks easily. 

Now USB is leading the way in providing fast charging standards developed and agreed upon by a cross-industry group, including leading vendors such as Apple, Samsung, and Google, as well as chip companies such as Intel and Texas Instruments. 

They developed a better cable ending – USB-C – and the next-generation USB charging technology known rather boringly as USB Power Delivery (PD).   It’s now considered the only true Fast Charge technology for smart phones, which is also compatible with laptops and tablets. 

How does USB PD work in the simplest terms?

Well, it’s actually quite straightforward. Power, measured in Watts, is simply Volts multiplied by Amps. So, with old USB charging, you might have between 5W and 12W of power (at best). But with USB PD, chargers can go all the way to 100W – over 8 times more power or 20x more power than the typical 5W chargers many people still use!  (Remember that Apple charger above?)

Most smart phones today charge in the 20W-45W bracket, so a PD charger offering anywhere from 20W to 45W is good enough. But if you use a higher power charger made for a larger laptop or tablet, that’s even better. Of course, you don’t need a 100W USB PD charger, but neither will it do any harm. 

USB PD continues to develop and is being stretched to 240W of power in the next generation.   This could permit e-bike/e-scooter or power tool batteries to be charged while also permitting charging some of the largest laptops or powering small desktops. 

Qualcomm has adopted USB PD in its QuickCharge4 standard, meaning devices supporting QC4 will also support USB PD chargers. In addition, Apple’s Lightning cable (with a USB-C adapter on the charger end) also supports USB PD chargers.  

Am I using USB PD Fast Charge today?

If your charger has a USB-C port, it may be USB PD, but not definitively. If you can find the specs, look for USB PD to be mentioned and voltage levels other than 5V (e.g. 9V) and/or power of 18W or more. 

If your charger has a USB-A socket, it is definitely NOT a USB PD fast charge charger. And just because your smart phone has a USB-C socket does NOT mean it’s a smart phone capable of USB PD Fast charging. 

And finally. 

We’ve not discussed loads of geeky terms here, such as Wh, or mAh but it is REALLY useful to understand a very simple relationship.  Watts = power. A Wh or Watthour is simply the amount of power that can be sustained for one hour – so you can be a powerful runner with a quick sprint, but a one-hour run is the power you can maintain for one hour – “energy”.

In electrical terms, there are two key components that make up power; Volts and Current (amps).  Multiply the two, and you get the Watts.  Maintain that for one hour and you get Watthours.  So, 5V * 1A = 5 Watts.  Maintain that for 1 hour and you get 5Wh of energy – a smartphone that runs at 1Wh will get you 5 hours of usage. 

So there it is. Fast charging in a nutshell.