Power up! The amazing evolution of the cellphone battery

When Nokia recently asked people what the most important thing was to consider when creating a new cellphone, the top answer, with 38%, was a long battery life. It’s easy to understand why. An amazing smartphone without any power is about as useful as a brick. Sometimes we forget that, in the past, batteries were almost the size of a brick, too. To remind ourselves just how lucky we are to get our days of talk time, we decided to check out how much batteries have evolved over the years.

The Nickel-Cadmium or NiCad battery

In 1987, Nokia launched its first handheld mobile phone, the Mobira Cityman. This beauty may have cost four and a half thousand dollars, but it still took six hours to charge and packed just a single hour of battery life. The reason the talk time was so poor? The Nickel-Cadmium or NiCad battery. Barely half the size and weight of the first rechargeable battery technologies ever commercialized in the 1800’s, the NiCad was not only large and heavy, but suffered from the Memory Effect. The meant that it had to be fully used up before being recharged, otherwise it would remember the shortened charge cycle and last for even less than an hour. It was also hot and changed shape when you used it for a longer time. Add to that the toxic nature of cadmium, and it was clear something better was needed.

Nickel Metal Hydride or NiMH battery

Thankfully, that something better turned up in 1989. The culmination of two decades of research, the Nickel Metal Hydride (NiMH) battery was thinner, lighter, non-toxic, and delivered a higher capacity in relation to its size and weight. Although it was still prone to the Memory Effect, you only had to completely discharge the battery after every 20th recharge. They also took less time to charge, and gave much more talk time. Unfortunately they still got very hot, as anyone with a cellphone in the early 90’s will remember. And they still changed shape.

Lithium Ion or Li-Ion battery

The battery that really revolutionized everything was the Lithium Ion or Li-Ion battery. First made commercially available in 1991, in 20 years of development the Li-Ion performance has improved nearly five fold. Without this technology, it would have been impossible to transform chunky cellphones into pocket-sized smartphones. The Li-Ion is thinner, lighter and typically provides 30% more standby and talk time than NiMH batteries of the same capacity. It doesn’t suffer from the memory effect so it no longer needs to be emptied before recharging. What’s more, all the components are environmentally safe.

Lithium Poly Ion or Li-Poly battery

But the search for longer talk time and a shorter recharge time continues, and since 2008 there’s been a new contender on the block. The Lithium Poly Ion battery or Li-Poly offers up to 40% more battery capacity than the NiMH battery of same size and is totally free of the memory effect. And because they don’t need a cell casing, they’re ultra light. Downside? They’re ultra expensive too.

The relentless quest for better, more innovative ways to power our cellphones continues. But in the meantime, what do you do to get the most out of your battery, be it a NiMH, Li-Ion or Li-Poly? If you have any top tips, we’d love to hear about them in the comments below.