×
Home Companies Industry Politics Money Opinion LoungeMultimedia Science Education Sports TechnologyConsumerSpecialsMint on Sunday
×

Charge of the battery brigade

Charge of the battery brigade
Comment E-mail Print Share
First Published: Wed, Oct 14 2009. 12 36 AM IST

BMW’s Mini E does 150 kmph and runs 240km on a single charge. But it needs a 23-hour charge for its 5,088-cell battery. The right battery could take a car 500km on an hour’s charge.
BMW’s Mini E does 150 kmph and runs 240km on a single charge. But it needs a 23-hour charge for its 5,088-cell battery. The right battery could take a car 500km on an hour’s charge.
Updated: Wed, Oct 14 2009. 12 36 AM IST
You surely wouldn’t have seen any of these yet: A slim “007” Swiss watch with a built-in phone, GPS, push email and video. Or a 3G smartphone with GPS, camera, push email, instant messaging and video, which runs a week on a single charge. There’s more. A luxury electric roadster that does 0-100 kmph in 4 seconds, recharges in 15 minutes and runs 500km on a single charge. Or a 100-seater airliner that uses no fossil fuel, is electric, recharges on the ground and flies 5 hours on a single charge.
All these are still in the realms of fiction for now. So why are we talking about them? Well, because the technology exists. We have super smartphones, watches with cellphones, electric cars, solar power and even electric aeroplanes.
BMW’s Mini E does 150 kmph and runs 240km on a single charge. But it needs a 23-hour charge for its 5,088-cell battery. The right battery could take a car 500km on an hour’s charge.
The missing link is the battery. The batteries you’d need for all this technology don’t yet exist. A slim wristwatch-phone’s battery would last 10 minutes on a call. The Reva electric car takes hours to charge, drives sedately and runs 100km on a charge. Electric planes, so far, are only limited to toys or light National Aeronautics and Space Administration (Nasa) test aircraft. The batteries needed to power commercial planes would be too heavy for the aircraft to lift.
In Europe, you can buy BMW’s Mini E electric car. It does 0-100 kmph in 8 seconds and crosses 150 kmph. It goes 240km on a charge and packs an amazing 204bhp in its 150kW electric motors. But to power all this, its huge 5,088-cell lithium-ion battery replaces the rear seats, making the car a two-seater. It can charge in 4 hours through a high-voltage charger, but as buyers discovered, topping up through household electric outlets meant a 23-hour charge time.
Battery technology is advancing, but not as quickly as other electronics. Five years ago, my Nokia 6310 ran a week on a charge. But then came the always-on 3G data, push email and GPS.
So all the tech news here belongs to the future—waiting for the batteries to be invented. I’d put the one-week smartphone at 2011, the watch-phone at 2013, the 15-minute/24-hour car at 2015 and the electric plane at 2025.
All charged up
(Left) Low-power technology can stretch battery life. The Amazon Kindle’s (Rs20,000, ships 19 October to India) zero-power e-paper display helps it run for days on a charge. A regular battery could last a year of moderate use in an LED flashlight. (Right) Sanyo’s Supercell. Launched this month, Sanyo’s new Eneloop (which comes pre-charged) is the first NiMH battery that lets you recharge it 1,500 times.
The popular lead-acid battery leaks acid, needs topping up with water, spews toxic fumes and is heavy. But it’s cheap and gives high currents—up to 450 amps per second is great for starting cars. And today’s sealed versions are safer and cleaner. Variants such as tubular batteries are great for sustained use at lower currents such as for household inverters.
Your electronics use other batteries. Zinc-carbon dry cells are cheap for flashlights, but die fast and leak. Alkalines such as Duracell or Energizer last much longer. Lithium-iodide has a long life and powers pacemakers and hearing aids. It’s the same for zinc mercury oxide, also found in hearing aids. Silver-zinc is ultralight, so it’s used in aeronautics.
Then there are the rechargeables. Nickel-cadmium was popular, but it has a “memory effect”: Its capacity declines if you don’t discharge it fully. It’s been largely replaced by nickel metal hydride (NiMH). Even better is lithium ion: It’s light and packs in lots of power. This is one reason it is used in most mobile phones and laptops.
Promising currents
A really promising one is lithium polymer. This is actually lithium ion, but the lithium is embedded in a solid polymer (plastic). This makes it flexible and adaptable to any shape: A battery could be designed as the rear cover of a mobile phone. There are also fast-charge versions. A Toshiba model can reach 90% charge in 5 minutes. Earlier versions degraded rapidly, but new ones can do 500 charge cycles before dropping to 80% capacity. So they’re great for phones and electric vehicles.
Different fuel
The fuel cell is the likely future of the battery. It’s a power source that is inexhaustible as long as you replace the “fuel”.
All batteries use chemicals that react to create electricity. In an alkaline cell, once the chemicals are used up, you throw away the battery. In a lithium ion, charging reverses the reaction and recreates most of the original chemicals. In a fuel cell, when the chemicals are used up, you simply replace them.
A fuel cell could use hydrogen or methanol or other fuels, making it react with oxygen in the air.
The zinc-air battery can make a neat fuel cell. The plain zinc-air battery is single-use—not even rechargeable. But build it so that the zinc is replaceable and you get a fuel cell. Zinc makes a nice fuel. It’s solid and easier to transport than hydrogen. Zinc-air batteries are getting efficient and are good enough to power vehicles. Pure zinc is non-toxic. The solid waste is zinc oxide, which can be reprocessed into zinc.
The aluminium-air battery packs even more energy, but has a low shelf life and high price. It’s used in some military products and it has potential in power-starved countries which have a lot of aluminium scrap.
Is there life beyond a battery?
(left) The Reva goes 80km on an 8-hour charge and the batteries make up at least 40% of its 665kg weight. A new lithium-ion version drops weight by 100kg and charge time to 6 hours, and extends range to 120km. (right) Nasa’s fuel cell is the next-generation battery. When it’s discharged, you replace the fuel. It’s good for electric cars or heavy-use electronics.
Not in this century. Someday in the future, we’ll see a planet-wide smart grid-tapping solar power round the clock. But even with wireless charging, we’d need batteries to store the power, especially in mobile devices.
Some call solar power an alternative. They’re wrong. Solar power needs a battery. My Citizen watch is solar-powered, but it has a capacitor-battery to store the power. We could power whole cities with solar panels, but how do we store the energy for nights or cloudy days? Such mega batteries don’t exist.
So wherever you go, down every road, there’s always one more battery. These are getting better, but it’s a long, slow, uphill road. And the battery keeps slowing us down, overtaken by the demands of electronics and electric vehicles.
*********
CONNECT
Listen | Music on high-fidelity
The Bowers & Wilkins Mini Zeppelin and Bose SoundDock 10 are fairly expensive systems for playing music from an iPod, iPhone or computer ($400 for Mini Zeppelin and $600 for Bose, available now). Both companies say the technology makes it worth it. The Mini Zeppelin streams digital data directly from a device using what it says is an audiophile-grade digital-to-analogue (DAC) converter, bypassing the DACs in music players. The Bose SoundDock 10 has a few tricks of its own, including a pair of proprietary Twiddler transducers (or speakers). Bose says it will offer an optional $150 Bluetooth dock to stream music from a phone. ©2009/The New York Times
Save | Clickfree HDD
ConJoin Technology Partners has launched Clickfree, an automated back-up device, in India. Easy to install, Clickfree allows you to back up your data by simply plugging it into the USB port of the computer. The hard disk drive (HDD) recognizes around 400 file formats, including Office files (Word, Excel, PowerPoint, among others), as well as music, videos, photos, email and Internet bookmarks. Clickfree HDDs are available in 2.5- and 3.5-inch sizes and the storage capacity ranges from 160GB to 2TB. Another device, Clickfree Traveler, is so small it fits into your wallet and is available in capacities of 16GB, 32GB and 64GB. By a Staff Writer
Scan | Set a higher dpi
If you have small photographs that you want to significantly enlarge when you print them, you should increase the scanner’s dpi setting. For example, if you have a 4x6-inch photograph that you want to blow up to 8 1/2x11 or 8x10, set the scanner to capture the image at 600 dpi, so that the photo doesn’t look as distorted or blurry when you print it at twice the original size. Scanning images at higher dpi settings means that all additional information being captured takes up more space and you end up with bigger photo files. If you are new to photo scanning, go to the ScanTips.com website. ©2009/The New York Times
Wear | Power jacket
Mountain Hardwear’s jacket has heating elements to keep you warm and a power adapter in the pocket that enables you to charge your iPod, digital camera, GPS device or cellphone. With the $240 jackets, you can adjust the temperature up to 100 degrees Fahrenheit with a toggle switch on the left front. The heating elements can be fully charged in less than 3 hours and a charge should last up to 8 hours on the lowest heat setting, according to Paige Boucher, a Mountain Hardwear spokeswoman. The jackets are designed as a mid-layer coat to be worn under a ski jacket or alone in warmer climes. ©2009/The New York Times
Prasanto K. Roy is chief editor at CyberMedia.
Write to us at businessoflife@livemint.com
Comment E-mail Print Share
First Published: Wed, Oct 14 2009. 12 36 AM IST