The battle of the batteries is hotting up. Reports claim Google is the latest firm to set up a team dedicated to boosting how long our phones, tablets and even electric cars can run for. And sources said the four-man team spends its days devising and testing different technologies from the flexible to the wearable. Reports claim Google is the latest firm to set up a team dedicated to boosting how long our phones, tablets and even electric cars (pictured) can run for. Sources told the Wall Street Journal that the four-man team spends its days devising and testing different technologies from the flexible to the wearable . The reports were made by Alistair Barr in the Wall Street Journal. Google has been working on similar projects since 2012 when former Apple battery expert Dr Ramesh Bhardwaj began leading a testing team. Mr Barr explained that Dr. Bhardwaj recently described how 'solid-state, thin-film batteries could be used in smartphones and other mobile devices that are thinner, bendable, wearable and even implantable in the human body.' He also referenced a video for Project Loon that revealed how Google has been working with experts at AllCell Technologies to develop batteries that function at subfreezing temperatures. This is vital for Google's Project Loon balloons designed to float near the stratosphere and provide internet to wider areas. Google has been working on similar projects since 2012 when former Apple battery expert Dr Ramesh Bhardwaj began leading a testing team. In a video for Project Loon (pictured), Google revealed it has been working with experts at AllCell Technologies to develop batteries that function at subfreezing temperatures . Fan site AppleInsider recently spotted nine job listings on Apple's official recruitment site in the past month that relate to batteries. These include one for an iOS battery life software engineer (pictured left) and another for iOS software power systems engineer (pictured right) The AllCell technology uses wax and a graphite material, for example, to help lithium-ion batteries absorb heat and spread it across the power pack. Last week, a team of Stanford University chemists unveiled an aluminium battery that can recharge in less than 60 seconds. Apple defines the Apple Watch battery on its Watch product page. It says its all-day battery life is based on 18 hours of use. All-day battery life: This includes 90 time checks, 90 notifications, 45 minutes of app use, and a 30-minute workout with music. Audio playback: The battery will last up to 6.5 hours when playing music. Talk time: Apple said the Watch can be used for up to three hours for calls. Workout: During this test the Watch lasted for seven hours when a workout session was active and the heart rate sensor was on. Watch: When used as a watch the device will last for 48 hours if checked five times an hour. Power reserve: When the Apple Watch's battery  gets low it switches into Power Reserve mode letting users tell the time for up to 72 hours - with four time checks an hour. Charging time: The company said it takes 1.5 hours to charge the Watch to 80% and 2.5 hours for a full charge. Apple's tests were carried out in March 2015 with a pre-production Apple Watch and software paired with an iPhone using pre-production software. Apple said battery life varies with environmental factors, use, configuration, and 'many other factors' so actual results will vary . It is said to be the first high-performance aluminium battery which is 'fast-charging, long-lasting and inexpensive' and is more environmentally friendly than alkaline batteries. It also can't catch fire like lithium-ion technology. At present the rechargeable aluminium battery generates about two volts of electricity, the highest achieved yet with aluminium,'  but the researchers said the battery has only half the voltage of existing technology. And Google isn't the only tech giant working on such plans. Last month, Apple began recruiting for experts to help boost the battery across its range of mobiles and laptops. At least nine job listings were discovered by fan site AppleInsider and include listings for an iOS battery life software engineer, a software power systems engineer, battery pack engineering manager and a cell engineer. In particular, the iOS software power systems engineer role said the successful candidate 'will be working on design and development of software for triage of battery life issues, modeling of power consumed by different parts of the system, and analytics to understand large scale battery life trends.' Atmel also recently announced its latest microcontrollers (MCUs) that can be fitted to a variety of gadgets and are so low power they can harvest energy from a person's body. The  SAM L microcontrollers are part of Atmel's 32-bit ARM-based MCU range and are powered by chip maker ARM's Cortex M0+ 32-bit processors. A number of Apple devices, including the iPhone 5S and iPad Air are powered by chips based around ARM technology. A team of Stanford University chemists recently unveiled an aluminium battery that can fully recharge in less than 60 seconds. It is said to be the first high-performance aluminium battery which is 'fast-charging, long-lasting and inexpensive' and is more environmentally friendly than alkaline batteries . Last month, Atmel released its latest microcontrollers (MCUs) for a variety of gadgets that are so low power they can even harvest energy from a person's body. Atmel said its MCUs extend 'battery life from years to decades, reducing the number of times batteries need to be changed in devices' Atmel said its MCUs extend 'battery life from years to decades, reducing the number of times batteries need to be changed in devices such as fire alarms, healthcare, medical, wearable, and devices placed in rural, agriculture, offshore and other remote areas.' They use a third of the power of rival chips and tests have shown they are the lowest power microprocessor ever made. The microcontrollers run on the firm's picoPower technology and Atmel's Event System that makes different parts of the device work together to carry out tasks. By effectively 'sharing' energy, the whole device uses less power and, subsequently, less battery. It can also manage how much energy is being used by other components to make them as efficient as possible. Plus, the technology is so low power it can harvest energy from the body using changes in temperature. During a demonstration of the microcontrollers at this year's CES, Andreas Eieland, Atmel's director of product marketing demonstrated how he could power a radio by placing his hand on a panel. This panel recognised a change in temperature between the hand and the room and this was harvested to create charge .
Reports claim Google is latest firm to test alternative battery options .
Sources said the four-man team  devise and test different technologies .
It follows Apple's recruitment drive  for battery and software experts .