Today, we take smartphones for granted, with external battery chargers to keep our devices running.

While it may be commonplace to carry an external battery charger wherever we go in order to make sure that our mobile phone battery will be able to keep up with our daily needs, only a few years ago, these devices and the packs that kept them going were not nearly what they have become.

While we might complain about having only one bar left on our current devices, they’ve come a long way.

A decade ago, the basic flip phone was the latest thing. Ten years before that, cellular phones were large, bulky devices that typically had an antenna that needed to be raised and lowered manually. A large amount of the bulk and weight of those devices was made of the mobile phone battery and even at that size, they provided only a small amount of usage time before they would run completely dry. At the time, it was frustrating, but typically acceptable since the devices were barely used, anyway.

The modern mobile phone battery wasn’t invented until the 1970s, but that tech barely compares to today’s power.

In 1973 a prototype of what would be considered the modern cell phone battery was first created using a concept from an engineer at Bell Labs. By 1977, it was being tested out in Baltimore, Washington D.C., and Chicago in pilot programs, and Japan did the same thing in 1979. The devices they powered were very large, wouldn’t come close to fitting in a pocket, and would provide 30 minutes of charge, at best.

Throughout the 1980s, a hint of additional popularity to cell phones encouraged the evolution in mobile device batteries. The limitations of the batteries at the time increased the popularity of the “car phone”, but there were a few that could fit into a briefcase and that were used by a certain niche demographic. By the 1990s, the batteries – and the devices they powered – shrunk a great deal more, considerably boosting their popularity and making these gadgets much more mainstream.

Smartphones and considerably more compact and more powerful batteries came about in the 2000s, and while they are light years ahead of their predecessors, the primary struggle that is now faced is in the fact that smartphones are used so frequently and for so many purposes throughout the average day that the built-in power bank isn’t enough. For this reason, external battery chargers have become today’s ideal companion for the average user. With the speed at which technology is currently changing, it is difficult to imagine what tomorrow will bring.