Startup touts ultrafast charging: What if a smartphone could charge in 12 minutes instead of two hours?

Apr 08, 2013 by Naveena Sadasivam weblog
An Exide forklift truck battery being charged using the rapid charging system. Credit: Potential Difference Inc.

(Phys.org) —Potential Difference Inc., a Nevada startup, has developed a versatile charger that it claims can refill the batteries in smartphones, laptops and even electric vehicles to 80 percent capacity in 12 minutes. That's a major improvement considering the Tesla Motors Supercharger needs 30 minutes to recharge 50 percent of a battery.

Dr. Yi Ding at the Georgia Institute of Technology first developed the technology in the late 1990s, and patented it in 2001. Now, Elliott Small, the CEO of Potential Difference, has acquired an exclusive license to commercialize the technology.

"We are working on partnering with manufacturers to integrate the technology with the of different ," said Small. Potential Difference has already teamed up with Chargetek to manufacture the with the and is currently running a crowd funding campaign on Indiegogo.com.

Predominantly, research involves innovation in the materials used to design batteries and in their physical configuration. But this particular technology modifies the method of charging without altering batteries themselves.

The has sensors to detect the temperature, voltage and current charge level of a battery, and these data are used to determine the acceptance. Generally, batteries charge faster at low charge levels as compared to when they are already partially charged. By first determining the state of the battery, the charger can optimize the current pulses it sends.

"This is what makes it unique and different," said Scott Moura, a in control systems and dynamics at the University of California, San Diego. "Batteries normally charge using a constant current but these chargers send current pulses."

Potential Difference has conducted testing on charger for lithium-ion batteries and its results show that common consumer electronics and electric vehicles can be charged fully within 16 minutes. While charging to 80 percent, the battery reached a maximum temperature of 42 degrees Celsius.

A major plus for implementation is that the charger is compatible with almost all consumer electronics. "The interface that connects the charger and device needs to be changed, but the charger remains essentially the same," Small said.

Originally, Potential Difference hoped to manufacture the chargers on its own but technological and market limitations pushed the company to connect with electronics manufacturers.

John Busbee, the CEO of Xerion Advanced Battery Corp., agrees that the charger will work best if customized to each electronic device. "It won't reach it's best potential without partnerships with the consumer electronics and battery manufacturers," said Busbee. "If the battery model is not reflective of the battery, it'll work, but it won't work as well."

However, Ding argues that the charging method is generic and depends mainly on basic battery chemistry. He feels that since most and consumer electronics use lithium-ion batteries, the specifications of the battery are immaterial. "That's the beauty of this kind of charging technique," Ding said. "It doesn't rely on who the producer is or the size of the battery." Since the charger first diagnoses the state of the battery before responding, Dr. Ding said the manufacturing details of each gadget are not required.

Moura is skeptical about the fast charging technique's effect on battery life. When high levels of current are applied, the internal resistance of the battery causes temperature rise and damage to the battery itself. Moura explains that since the electrodes in the battery are like a sponge soaking up lithium ions, sending high pulses of current repeatedly would cause repetitive expansion and contraction of the electrode, ultimately resulting in electrode fractures and battery failure.

Potential Difference has not yet conducted cyclical testing on the device and does not yet have data on how many cycles of charging an average battery can withstand.

Explore further: Environmentally compatible organic solar cells

4.6 /5 (7 votes)

Related Stories

NTT Docomo's new smartphone features wireless charger

May 19, 2011

(PhysOrg.com) -- Charging your cell phone can be a hassle, mostly because you have to find your cord, and if you are anything like most people, you don't have just one charging cord lying around your house. ...

Battery Wrapped in Solar Cells Recharges in the Sun

Mar 02, 2009

(PhysOrg.com) -- Although you can buy solar charging devices for rechargeable batteries, it would be even more convenient if batteries had built-in solar cells. Sitting in sunlight, the battery could then ...

Recommended for you

Environmentally compatible organic solar cells

19 hours ago

Environmentally compatible production methods for organic solar cells from novel materials are in the focus of "MatHero". The new project coordinated by Karlsruhe Institute of Technology (KIT) aims at making ...

Floating nuclear plants could ride out tsunamis

21 hours ago

When an earthquake and tsunami struck the Fukushima Daiichi nuclear plant complex in 2011, neither the quake nor the inundation caused the ensuing contamination. Rather, it was the aftereffects—specifically, ...

Unlocking secrets of new solar material

21 hours ago

(Phys.org) —A new solar material that has the same crystal structure as a mineral first found in the Ural Mountains in 1839 is shooting up the efficiency charts faster than almost anything researchers have ...

Ikea buys wind farm in Illinois

Apr 15, 2014

These days, Ikea is assembling more than just furniture. About 150 miles south of Chicago in Vermilion County, Ill., the home goods giant is building a wind farm large enough to ensure that its stores will never have to buy ...

User comments : 22

Adjust slider to filter visible comments by rank

Display comments: newest first

Hev
1 / 5 (2) Apr 08, 2013
And how about improving the battery life and charging on iPhones etc. They are hardly mobile at present, the battery drains even before you have used it. This must be more important than making them bigger and heavier. (The designers seem to have lost the plot they should be making them smaller and lighter - and with a better battery!)
Eikka
1.4 / 5 (5) Apr 08, 2013
"Batteries normally charge using a constant current but these chargers send current pulses."


This is completely counter-productive. The batteries have a maximum amount of current they can recieve that depends on the state of charge, because pushing more current in raises the cell voltage due to internal resistance and once it goes over 4.3 volts on lithium cells, you're risking a fire and seriously damaging the cell.

So, a charger that inputs the maximum allowable current continuously will always input more energy faster than a charger that limits the same current into pulses. To deliver the same amount of energy in the same time, the pulsed current would have to be much higher, and would drive the cell voltage beyond safe limits.
PPihkala
not rated yet Apr 08, 2013
Eikka: I think that current pulses allow them to measure the state of cells between pulses, which enable that pulse charger to maintain bigger average charge currents than current constant current chargers do. By using high PWM ratios like 99:1 (99%), the time difference versus constant current charging will be negligible.
ian_j_allen
2.5 / 5 (2) Apr 08, 2013
Eikka: And yet they have a patent and are moving into commercialization of the technology, both of which of course require a working prototype in order to convince investors and patent officials.

Got a hunch here that you dont actually understand this system in its entirety.
antialias_physorg
1 / 5 (2) Apr 08, 2013
Pulse charging isn't exactly a new technology
http://en.wikiped...er#Pulse
Pulse charging has been around in commercial products for over a decade. The reason why it's not done more often is that the electronics for it cost a few cents more than for a constant charger.

The novelty here is, as I read it, that they adaptively modifiy the pulses during the charge cycle.
QuixoteJ
3 / 5 (2) Apr 08, 2013
...and electric vehicles can be charged fully within 16 minutes
Definitely want to see more details about this claim. Which electric vehicles, etc.
antialias_physorg
1 / 5 (1) Apr 08, 2013
...and electric vehicles can be charged fully within 16 minutes
Definitely want to see more details about this claim. Which electric vehicles, etc.

Would be neat for power stations - and would put an end to 'range anxiety'.
But you're not going to charge off of wall current in 16 minutes. Your home installations aren't equipped to serve up that kind of power (to be fair: they dont need to. When you're at home then a 6-8 hour charging cycle at night is perfectly acceptable).
Manitou
not rated yet Apr 08, 2013
Why do they promote the 80% in 12 minutes instead of the 100% in 16 minutes? Isn't the latter more impressive?
packrat
not rated yet Apr 08, 2013
@Manitou
Because as a general rule the charging current has to be cut down doing the last 20% or so and quite often it takes as long or even longer to get that last 20% in as it does to charge the first 80%.
Eikka
not rated yet Apr 08, 2013
Eikka: And yet they have a patent and are moving into commercialization of the technology, both of which of course require a working prototype in order to convince investors and patent officials.


You do realize that patented devices don't actually have to work as intended - they just have to be original.

That's how nearly all the scammers operate.

I think that current pulses allow them to measure the state of cells between pulses


Fast lithium cells are charged with as much current as the charger can possibly manage until the voltage hits 4.3 volts or whatever the ceiling is that they set. Then the charger automatically reduces current to keep the voltage there. It doesn't need to stop to measure the cell.

If a current pulse causes the voltage to rise over the limit voltage, it causes damage to the cell.
Eikka
5 / 5 (1) Apr 08, 2013
Pulse charging has been around in commercial products for over a decade.


Pulse charging works for lead and nickel batteries because they tolerate overvoltage and overcharging. Lithium batteries don't - they burst.

Pulse charging a flooded cell battery is slightly less efficient because any overpotential increases the formation of hydrogen.
NickFun
1 / 5 (1) Apr 08, 2013
Should I invest now or wait until some of the noted objections have been addressed?
packrat
not rated yet Apr 08, 2013
Should I invest now or wait until some of the noted objections have been addressed?


Well since share holders can't normally be sued along with the company, go ahead and invest.... Just don't plan to make much money on it because this is lawsuit bait of the best kind.
dan42day
1 / 5 (1) Apr 09, 2013
My only objection is that I will lose my standard excuse,"Sorry, my phone was in the bedroom charging and I missed your call."
Skepticus
not rated yet Apr 09, 2013
Potential Difference has not yet conducted cyclical testing on the device and does not yet have data on how many cycles of charging an average battery can withstand.

There you go. The kicker. It should work and you should expect to buy more batteries more often.
alfie_null
not rated yet Apr 09, 2013
I'd echo Moura's concern regarding battery life (number of cycles). Particularly if this is to be used for devices that don't have replaceable batteries.
I'd think you would want data from recharging from various depths of discharge, over a number of cycles. It might well turn out there is tuning to be done to ensure your recharger isn't causing premature failure.
ODesign
not rated yet Apr 15, 2013
Battery cycles might actually improve.

NICD batteries develop whiskers that reduce battery life over time, but a brief power surge can break the energy sapping whiskers of and restore for a while the usefulness of NICD batteries. google "recondition NICD batteries"

I think this reconditioning technique is actually the same effect as fracturing the electrode mentioned in the article as a problem, only it's done with a different strength of pulse and duration to fracture the the whiskers and only after several cycles to minimize damage to the electrode itself. Maybe the pulse charging strategy could be engineered to have similar benefits to batter charge cycle counts or otherwise engineered to minimize the fracturing of the electrode.
antialias_physorg
not rated yet Apr 15, 2013
I'd echo Moura's concern regarding battery life (number of cycles).

Does this really matter? Phones are replaced far more often than they need to be (i.e. their designed battery life is already way beyond what is the most common use case).

It's a bit like with car manufacturers. What good is it to design a motor that will keep running for 20 years when on average consumers buy a new car every 10?
Eikka
not rated yet Apr 23, 2013
when on average consumers buy a new car every 10?


The average age of cars is around 10 years old. To get to that average, a significant number of cars have to last at least 20 years.
antialias_physorg
not rated yet Apr 23, 2013
You missed the point. The very occasional guy who keeps his cell phone for 30 years doesn't matter in the calculations of companies. It's the time the average user keeps his (and 1 or 2 standard deviations to either side)
When did you ever hear of anyone complaining that his phone battery had degraded significantly - and someone who hasn't kept his phone MUCH longer than the average? Never.
Eikka
not rated yet Apr 24, 2013
When did you ever hear of anyone complaining that his phone battery had degraded significantly


When smartphones first started appearing, because they would eat up the charge in about a day, and the lithium batteries would only last for a year and a half, two years tops. As you approached 700 recharges, you started to run out of charge half way through the day - like those old NiCD brick phones that had to be tethered any time you weren't carrying it.

That was one of the major flaws of the original iPhone for example. Its battery would die before the contract was fully paid out, and it wasn't even replaceable, but since it had so few and such fanatically devoted users, the criticism was put down as sour grapes.

Nowadays they have bigger batteries that last two days on a charge if you don't stress it too much, so it's barely enough to last until you replace the phone. Still, I've run down a couple cellphones to the point where you notice they don't stay on as long anymore.
Eikka
not rated yet Apr 24, 2013
The very occasional guy who keeps his cell phone for 30 years doesn't matter in the calculations of companies. It's the time the average user keeps his (and 1 or 2 standard deviations to either side)


Of course, but you were talking about cars.

Because the average car owner doesn't buy a new car every ten years. There's a group of car owners that buy new cars every 3-5 years so they don't have to mind fixing them or getting them through MOT tests, and they always get to drive a new car. The rest of the people buy second hand cars. Few keep the same car until it's all done for.

If a car manufacturer targeted only those 3-5 year owners, the brand reputation would take a serious hit because the far greater mass of people who buy the cheaper second hand cars would regard the brand as crap, and that would reflect on the buyers of the new cars because they would see the resale value drop dramatically.

Phones and cars are whole different markets. You used the wrong analogy

More news stories

Sony's PlayStation 4 sales top seven million

Sony says it has sold seven million PlayStation 4 worldwide since its launch last year and admitted it can't make them fast enough, in a welcome change of fortune for the Japanese consumer electronics giant.