Battery Sharing

We were at a family event last night and all three of my kids had the battery die on their phone before the event ended. I had over 80% battery on my phone. What I wished I could do was easily give them some of my battery to get them through the night.

I had this image in my mind of holding the backs of two iPhones together and hitting a button and having the one with lots of battery give some of it to the one that was running out.

Even if such a thing required connecting the two phones with a cord, it would be pretty great.

I’m wondering why this isn’t possible, particularly the connecting two phones with a cord and having one give some of its battery power to the other. I’m sure there is someone out there much smarter than I am about battery technology who can answer this question.

Of all the great things that Apple and the Android phone companies have brought to the market over the years, the one thing that still sucks about smartphones is battery life. And with billions of people walking around with these devices in their pockets, it seems that tapping into all of that excess battery power to give a dying phone some extra life would be an incredible feature. It can’t be that they haven’t considered it. It has to be that its not easy to do. But I’m not sure why.


Comments (Archived):

    1. fredwilson

      that’s awesome. i had no idea Samsung had this in market. does it only work from samsung phone to samsung phone?

      1. Cam MacRae


      2. Tim Connors

        a number of samsung phones do it. they can power any other device with microUSB. I’ve always thought Tesla/Nissan/Ford should do this to solve range anxiety in electric cars too. Ship each car with a car-to-car charging cable and let me hail another nearby tesla/leaf/volt if I’m out of range the way I hail a lyft. I can pick up a quick 10 miles of range in 10 minutes to get me home or to a charging station. Charge $50 for it which goes to the driver who responded to my request.

        1. LE

          A nice idea. Maybe a variation of this is a franchise of “floating charge vehicles”. Call it “EEE” (not “AAA”). The charger comes to you when you are parked somewhere and juices your car (and you don’t even have to be there).Not as primary power, but as “top off” power. Call the “floater/topper” from an app. Pricing right on the phone.Quick napkin math says that at scale, given what people will pay to avoid anxiety, the idea would work. Takes advantage of the unemployed economy as well. Not exactly green but solves a problem and can be justified and rationalized by encouraging more electric car usage.

        2. Matt Zagaja

          Great idea please forward to Elon.

          1. Tim Connors


          2. Alex Murphy

            This will probably be in a Tesla Software update tomorrow.

          3. Nick Ambrose

            Definitely seems like something AAA should/could add to their service … instead of “We bring you a gallon of gas” … we bring you 10 miles of charging !

        3. Matt A. Myers

          Piggybacking off of them while you both drive whatever required distance…

        4. Sebastian Wain

          When I skimmed your comment I first thought about charging your electric car with your samsung phone. Probably with more than one…

        5. Kathy Pappas

          This won’t work. People don’t buy cars to help others or to make money from it. Will you hail me out if my tesla gets stranded if we both are around Los angeles area. I give you $100. You tell me

    2. Jon Michael Miles

      I have an S5 and didn’t know about this. Off spine to Fred’s point, but the cable mafia always overprices things while the commodity pressure has made this pretty cheap:

      1. Nick Ambrose

        I didn’t know that either! Let’s hope Apple doesn’t now instantly patent the idea and sue them before I can order one πŸ™‚

    3. kenberger

      yup, I have this cord. Problem is, i’ve never used it because I never think ahead to carry the cord.The Note 4, and upcoming others such as S6, have a rapid charging feature– this is coming to lots more phones. So today when I head out for a long travel or conference day, instead of carrying the battery charging pack I used to carry, I just put the fairly small power plug + a very short usb cord in a pocket. When phone is tapped, a 10-minute charge gets me thru the rest of the night, I could do this for multiple days, and I don’t need to re-charge the charging pack anymore. 10 minutes (or even 5) is short enough for me to wait around near the phone.Also, wireless charging is coming to lots more phones very soon (like the S6). And, expect to see lots more wireless charging hardware around (Ikea just announced furniture w/ this built in

    4. Josh Bruegger

      I need this, only for iPhone! I just found this forum and it’s super helpful! Thanks for the link!

  1. Harry T

    I’m pretty sure I saw a crowd funding campaign around this concept a few months back. Will try to dig it up.

  2. omarsar

    Super idea for what seems like a killer feature.

  3. Eugenio Perea

    Batteries are the Achilles’ heel of a few industries, mobile wallets included, and no one seems to want to talk about it. I’ve long suspected that battery capacity is what drove the introduction of the 5 inch plus smartphones.Your idea is great, by the way!

    1. fredwilson

      great. someone is thinking about this!

        1. William Mougayar

          that’s a cool device.

  4. William Mougayar

    Even better, how about a smartphone that can charge itself from your body heat.

    1. Kirsten Lambertsen

      That’s the kind of thinking that’s called for here πŸ™‚ Seriously.

      1. William Mougayar

        Thinking-out-of-the-battery πŸ™‚

    2. PhilipSugar

      We made a prototype that charged from movement. It was a tube that you shook to power the phone. (Insert joke here)The problem was that if you were willing to carry that you could carry a smaller battery tube the size of lipstick that costs $12 on Amazon…

      1. William Mougayar

        I was reading about the body heat transfer, and apparently they need to improve the loss ratios. It’s currently at 2% whereas it needs to be at a minimum of 12% in order to transfer efficiently.Yeah, I have 3 of those small devices, from events give-aways. I did use them recently during a power failure at home actually, and got about 30 mins each.

        1. PhilipSugar

          That one gives a full charge. A co-worker and I kibitz about which is better. He has that one I have the Nomad below.

    3. Lil Pong

      Does it require rubbing the phone to the body to gain heat ?

      1. William Mougayar

        maybe that might increase the heat transfer.

        1. Lil Pong

          in which case I would advise the phones to absorb heat from almost any surface, not just the body. This can be done adding a seperate component inside the phone and will ensure battery from dyingLittle nerdy but a thought to mull over

          1. William Mougayar

            So, it’s conceivable to expect self-charging smartphones in the near future, I would bet.

          2. James Ferguson @kWIQly

            If it is based on heat transfer I will take your bet.Motion is ok its mechanical but heat is the lowest grade of energy there is (its random disorganised energy) – the only way to use heat to extract energy is to move it to somewhere colder-So we must ask which part of your cellphone would stay cold if you surrounded it in something warm ? – Correct – it will not happen.To take this further if you make a meat stew and heat it up to 200F and drop a phone in, as soon as the phone is nice and warm all energy flow into the phone has stopped (because it is now as hot as the stew).Having addressed this conundrum – you must next turn that heat into electricity (for which we use powerstations ) these are famous for being bigger than your pocket.:)

          3. Ernest

            Smart lad! Is there anything sensitive enough to detect the planet’s motion in space? Then use that mechanical energy to generate unlimited power?

          4. James Ferguson @kWIQly

            They call it tidal power !Moon moves round us , water sloshes back and forth – big waterwheel (turbine) spins – we make energy !

          5. Ernest

            Ha! Cheers. Under our noses, but if that tech could be shrunk into a portable device we could have unlimited free power right? Heat is awful at energy creation – think combustion motor and turbo charging. All that cooling required. Feels like mechanical has some huge potential. I think? I’m a software engineer so my knowledge in this space is limited πŸ˜‰

          6. James Ferguson @kWIQly

            Sadly gravity though mechanical is weak. It takes “big” things to be influenced significantly – Seas and celestial bodies – these are not traditionally portable πŸ™‚

    4. SubstrateUndertow

      I wonder what % of users would choose a slightly thicker phone as an option if it provided significantly extended battery life ?

    5. Dr Washington Y. Sanchez

      Or a battery that runs off Coke. Just pour a can into a charging dock and hook it up to multiple phones.

      1. William Mougayar

        wow. how close are we to that?

        1. Dr Washington Y. Sanchez

          Typical academic response: 5-10 years.Reality: we’re waiting for Elon to do it πŸ™‚

    6. James Ferguson @kWIQly

      Requires a heat gradient – Ie heat only flows from hot to cold – to achieve more (a fridge you need a heat pump and additional power source).Recoverable energy is proportional to gradient . So if your battery is anything like warm enough to hold in your hand this will not fly – sorry !Or battery needs a cold heat dump – big fins like laptops used to have on their processors. – you could carry a bucket of cold water around to achieve this in a compact way – but then again πŸ™‚

  5. Dan Kantor

    Looks like you can do this with the new USB-C. Hopefully it comes to phones soon.”Forgot your power adapter? Plug in the optional Type-C to USB A cable, and top up from any traditional USB port, your phone charger, or a USB power bank. It won’t charge as fast as the included 60W supply, but it’s handy in a pinch. For the truly adventurous, you could even charge your Pixel from another Pixel!”…

    1. fredwilson


    2. Ernest

      USB-C feels like we are coming back to the old dark days of exotic cables aka HDMI costing an arm and a leg. But the spec is super! Hopefully price will be dragged down.

    3. Peter Watts

      “**Pixel to Pixel charging is possible, but it won’t charge all that fast. You could theoretically connect your Pixel to itself, but we recommend against experimenting with perpetual energy machines.”

    4. John Revay

      I thought I read a review of the new Powerbook w/ USB-C..that if connected to an iPhone – the charge could go either way re: Powerbook charges phone…or Phone could actually charge Powerbook.

  6. LE

    One issue with the “bum a smoke” concept is that it still requires one party to carry a cable that is male to male.

    1. fredwilson

      i would carry it for my own benefitlike carrying a lighter and bumming the cigarette

    2. Ernest

      Doesn’t phone charging furniture solve this problem? Or maybe stacking one phone ontop of the other to charge where no phone charging furniture avoid cables?

  7. Ernest

    Why don’t phones have Kinetic motion charging so they always have juice. When they run out the owner can shake it around or go for a walk (health incentive) to charge it. I hope Apple’s $10k watch at least has this feature like most high end watches have for a long time.

    1. LE

      People keep making fun of that 10k watch (or whatever it costs). But I can tell you that if I sold Life Insurance or Real Estate (I don’t) I would go out immediately and buy that watch. No question about it.Because I know that it would grab attention, I’d get comments, and I’d be able to pick up a whole bunch of leads and prospects in the process. I had a similar expensive thing (not a watch) and was surprised at what a man magnet it was. I kept thinking “boy if I sold life insurance I would buy an even nicer model ..”And assuming there is a resale value for it, your cost of “client acquisition” is not the gross price of the watch, but the net price after you sell it a bit down the road, after the novelty has worn off. People often miss this obvious point.

      1. Ernest

        Yeah you’d definitely fool someone who is materialistic. Not a long term strategy.Let’s solve real problems vs creating a facade.

        1. LE

          Yeah you’d definitely fool someone who is materialistic. Not a long term strategy.Let’s solve real problems vs creating a facade.What is wrong with people that are materialistic?Who is to judge what someone decides to spend their money on as right or wrong?Who says if someone makes a comment on something that they see you wearing (or driving), that they are materialistic? If someone says “hey! there is a purple cow” does that mean that they like farm animals? Maybe they never saw a purple cow before.What does any of this have to do with “solving real problems” anyway?What’s wrong with doing something to get attention if that serves to be a conversation starter? And gets you business?

          1. Ernest

            I’m not critiquing people that are materialistic just pointing out that your approach will only fool someone “who is materialistic”. The trend is moving towards trust & knowledge based relationships not shiny suits πŸ˜‰

          2. LE

            Re-read what I am saying. Someone possibly appreciating what you have and making a comment doesn’t make them materialistic. (Although they could be separately. )Why do you keep using the word “fool”? Where does that word come into my example?If you want, think of it as a “gimmick” to draw attention. And once that ice is broken perhaps business can be done.

  8. LE

    Somebody probably already has this patented (and that could play into the answer to “why not”)And as a matter of fact, search of patent database revels this:17. The first user interface device of claim 1, wherein the first user interface device comprises at least one of a personal computer, a handheld computing device, a personal digital assistant, a cell phone, and a digital music player.…(And there are for sure others,[1] this was a quick check)[1] Where “others” is “not some guy in NJ” but a major corporation. I would guess that Apple must have thought of this and has patents pending or issued for the concept.

  9. William Mougayar

    Oh, being in LA, you could wear the Solarmonkey Adventurer on your back, and they can walk up to you and get charged up that way.

  10. Matt Kruza

    Anyone use these guys ? (basically a slim phone case for $99 that “doubles” battery life..). They are well funded I think and had a super bowl ad. Seems kinda like a no-brainer to use, but I literally know no one who has one. Any feedback?

    1. Brian Lund

      I have been using their XL Powerstation for a while now. It’s compact and can charge two devices at once….and quickly. It has been a lifesaver on long road trips when the kids tablets have run out of juice; just put it in the back seat between the two of them and they can continue to Clash with Clans and mine diamonds to their hearts content.

    2. Matt Zagaja

      I know others that have, but I purchased a small Anker charger (… for $12.99 from Amazon. Fits in my pocket for charging on the go and no added bulk. Also easier to share when out and about. To be honest the only time I’ve really needed it has been when at big conferences like CES, long day trips in cities I’m unfamiliar with and using GPS, or days I do phone banking for politicians.

    3. lisa hickey

      I have a case for my iphone that adds battery life, and it works fairly well. The only problem is that using headphones with that battery case now requires a different cable and charging the case also takes a different connector cable than charing my phone, so the whole thing requires more management and is more complicated than I would like. I’m constantly taking the case off to actually use the iphone the way I would like to, but then putting the case back on for protection or to give a little extra charge.Fred’s post reminded me of two related things — my daughter in college said that about 25% of the people she socializes with has those battery cases, and that whenever she goes to parties, the people without the battery cases are always asking the people with the battery cases if they can borrow them for a quick charge. Kind of like the scenario Fred described.Also, years ago, back when I had an iPod but not an iPhone, I was climbing Mt. Kilimanjaro and was going to be away from any electrical outlet for an entire week. No place on the mountain to re-charge. At that time, Apple sold a device where you could put a pair of regular lithium batteries in a case, and plug the iPod into that case to re-charge it. Not even sure if that is an option now—those were the old days. But at the time it worked great and I did have music my entire hike without never needing to find an electrical outlet.

    4. Mark Birch

      I am a phone power user, my company’s mobile CRM is on it and I use it for all sorts of work stuff throughout the day. So I got the Morphie for my iPhone 5s and it is awesome as it lasts a full day. This is especially useful for shows that have really poor cell / wifi coverage which quickly drains the battery. The Morphie has been a lifesaver in those cases.What is not awesome is the stupid dongle extender for the headphone jack, but Morphie will send you free replacements if you submit a request.

    5. Thomas Mullooly

      I was reading the post from Fred thinking “just take your phone out of the mophie case and hand it to your kid!” Yes, yes, I know they may not have the same version or style of phone, but that seems the simplest solution.

    6. Doblet

      I used to use Mophie (had every model for iphone 4, 5s, 6) and bought them for $100+ a pop.The problem is that I’d have to carry a mini-USB cable around to charge the Mophie, then remember to charge the Mophie, or else my phone would again be dead. Also, the clunky case is an insult to a thin iphone that I keep in my front pocket.That’s why we created Doblet— ZipCar for batteries. Just launched in SF, expanding into +1,000 locations including major hotels, bars, restaurants, and chain businesses. Grab a battery, keep it for up to 5 days, and you’re never worried about losing power again.For the price of one Mophie, you can get 4-years of unlimited membership to Doblet!Check it out!

  11. Robert Heiblim

    It can be done, but it is not popular as it drains your battery. I think the stand-in are all the portable battery packs on the market today.

  12. LIAD

    Sharing economy was always meant to be about optimising asset allocation.Battery sharing is one thing. I always thought about brain sharing. Be it intellect, empathy, wisdom or any other aspect of brain power.Someone has a surplus. Another a deficit. A simple marketplace app and voilΓ .

    1. William Mougayar

      That will give a new meaning to the terms “brain washing” or “brainstorming”.

  13. LE

    Apple was roundly criticized when the iphone came out and didn’t have a changeable battery. But Apple knew enough about human behavior and human nature to know that people would buy the phone and overlook that pain point. Up until that time, just about all phones had changeable batteries. Right? At least any of the ones I ever bought.It’s the “lust” factor. You don’t kick a pretty girl to the curb or a finicky Ferrari out of your garage just because it has a few “behavioral” problems. [1] You become addicted and “can’t leave”.This is one thing that is roundly missing from the tech industry at many companies.[1] With dining, if the food is good enough people overlook that they have to wait in line hours to get seated and go to great lengths to secure tables and so on. Many examples like this.

    1. Matt Zagaja

      Except for 6+ Apple seems to trim device size year over year to keep the same battery life. They must have some kind of data that shows that the battery capacity works for 80% of consumers or something otherwise I think we’d see a same size phone with larger battery in subsequent years.

  14. Guest

    Oneplus One users not effected. :)IMHO, manufacturers should simply try to only make devices that get a full day of regular use out of a battery.

  15. James Queen

    I’m in motion a lot and my backpack is always full of cables — lightening cable to charge my iPhone + tether my laptop when necessary, charger for my macbook air, and then if I know I’m going to be out for awhile often a mobile battery (which of course I need to remember to charge with a separate cable).Really interested if there is a cable-less solution of either charging through motion/solar/some other method or having wireless charging infrastructure (like ubeam but distributed in some way akin to tesla charging stations).

  16. Jon Michael Miles

    Everyone in my office has one of these or something like it –

  17. rikardlinde

    As microrenewables gain traction I think we’ll see more sharing of electricity, not just between phones but between anything that uses electricity, two-way electricity if you like. One hurdle is creating a standard for this and a protocol so tools can exchange electricity no matter who built them or where they’re from. I doubt today’s companies are up for it, the idea of electricity flowing one way is deeply entrenched in our tools and our minds.

    1. Jon Michael Miles

      I look forward to wireless charging being as ubiquitous as wifi – that really is the solution – particularly at a grid level scale.

    2. fredwilson

      Right. But we need to start thinking of two way flow

      1. James Ferguson @kWIQly

        I agree – As renewable s turn up on the grid we are moving from hierarchy to peer to peer. Trouble is renewables are zero marginal production and volatile (weather) – any unified market suffers and you need “demand response”. (In normal terms “demand price elasticity”)So your two way flow abstraction is actually about locally reducing one way flow s (mitigating load at bottlenecks) which makes huge sense.I wrote to @wmougayar recently about this – as the energy grid must end up as local peer 2 peer marketplaces for trading purposes (because equilibrium price is local even if all else is constant)It is necessarily a huge network effect concept becauseEnergy is not a commodity when it is in the wrong place (oil underground carries much more energy than the same amount of oil when delivered in the form of electricity)This means local low transaction cost micro-trading is the only way to arbitrage the market efficiently. Blockchain for the win.

  18. Mark Birch

    Need Uber for phone charging…

    1. LE

      Maybe tinder for phone charging is a better analogy.

      1. Mark Birch

        Could make for an intriguing twist on the whole dating apps market…

      2. Daksh

        “Charged Dating”! 100% success story, waiting for someone to pick this up…

    2. vruz

      We need chatroulette but for batteries.We need youtube but for phone chargers.

  19. alok nandan

    @fredwilson:disqus: Check out -> (Tony Fadell is on the Board, Samsung is one of the investors).

  20. lisa hickey

    As I’m reading and commenting, the piece of Fred’s post that is most interesting to me is less about the tech solution and more about the “sharing”—the idea of easily connecting to other people for more power. Battery sharing could become a social ritual as much as a solution to an individual problem.

    1. Richard

      How about sharing human power!!

      1. lisa hickey

        Exactly. I answered this in the comment above.

    2. Ernest

      I disagree. Sharing is not a new concept. Existed before tech. The problem that was realized here is disconnect from the grid. Battery power is a positive correlation. Finding “sharing” interesting is like saying that you find “talking” interesting when in fact it’s how we communicate using new technology mediums like mobile that should be the focal point of interest.So in battery context, we can question whether current technology is limiting in providing uninterrupted value. Answer is yes. And what form of execution is required to solve this. For example, a world where power is in abundance through kinetic charging or fuel cell like battery technology or Tesla’s wireless charging. Or better still all 3 combined in small doses to sum the power requirements of devices to always be on the grid. We deliver value through this connected grid.

      1. lisa hickey

        Ok, yes, I agree with you Earnest. I am unfortunately the same person who does find talking interesting. If there was unlimited power available—then it would no longer be a problem. I’m all for an internet of things that became charging stations, or if wireless charging could be widespread without screwing up electromagnetic fields, or if we got kinetic charging to be adopted. I’m certainly not opposed to tech-only solutions for a real problem that I encounter all the time.But in the meantime—and I’m sure I wasn’t clear–what I really like doing is watching human behavior as new technologies emerge and then using those behavior patterns to make forward progress in other areas. Fred gave an example of watching a social situation where there wasn’t enough power for everyone. On another comment thread I noted that at college parties people would ask to borrow each others battery cases to charge their phones. And I like watching the social rituals that evolve as technologies evolve too. Camera phones changing social behavior is so many ways is a prime example. And watching people in real life social situations “share power” is interesting to me in ways that just “sharing” might not be. “Giving away your power” to others just has implications to me for where I see our world heading in a way that makes it not just technologically easier and better but more profound from a human interaction standpoint. We see how the internet can be the great equalizer, but moving towards a world where people can give away their power (literally their battery power and metaphorically all sorts of power) is just interesting to me. I certainly find the tech only solutions interesting, but I find the tech + changes in human behavior more so.

    3. fredwilson

      Yessssssss. The gift of power would be very powerful at certain times

      1. James Ferguson @kWIQly

        NOoooooooooo – Not possible – see my post above.Possible if you rewrite Jacoby’s Law – and get rid of Joule (what we geeks measure energy in) and finally Ohm (resistance ) collapses too.In short you have physics or you have efficient electrical energy sharing between similar devices – but not both in the same Universe (as far as we know)

      2. PhilipSugar

        Any good sales person has several batteries during a conference.

    4. Robert Metcalf

      I’ve been toying with the idea of a solar charging station (not an inherently interesting idea), but that requires at least two people to be plugged into the device for the charging to occur. So, you leverage technology to somehow promote human connection – at a minimum you might have to talk to that person next to you at the coffee shop to see if they’ll charge with you. Just an idea, but the energy itself is so cheap, that the value has to come from elsewhere.

      1. lisa hickey

        I love that idea as a concept. Of course, I can only imagine the number of cheesy pick-up lines that could come out of asking the person next to you if they would charge with you. But…what I like is technology that accelerates serendipitous connections. The way that Twitter or Tinder accelerates serendipitous connections online, but now you are accelerating serendipitous connections in real life. I can see that being one of the ways the future is moving. I can see wearables being a part of trend as they become a way to make visible certain social signals that will also accelerate unexpectedly relevant connections.

  21. PhilipSugar

    I love this device. I know you can buy others, but the key to this is that you never forget it and you get another charge. You plug it in at night and then the next morning you have two full charges on your iPhone. The only two non five star reviews are by an idiot that didn’t realize you need the apple charger, and the other that was using a bad cable. Actually I got this for half price on the pre buy so I’m really happy.…As an aside I always sat and wondered how people use up their batteries. But now I realize my phone uses batteries twice as fast in places like NYC.

  22. Matt Zagaja

    A while back there was a great post called “The Ultimate Guide to Solving iOS Battery Drain” at http://www.scottyloveless.c….Not sure how much translates over to Android, but I think that the use of notifications is probably a big culprit for many people that have battery drain struggles on iOS.

  23. Kirsten Lambertsen

    Whenever I say, “the person who solves batteries is gonna be a gazillionaire,” people look at me like I’m crazy and say, “batteries HAVE been solved.” (Of course, I understand, like, one thing about how batteries work, so there’s that.)Maybe wireless charging will be the answer. Maybe all the things around us will eventually become charging stations. But I’d still love some crazy person to ‘solve’ batteries (as in lightweight, extremely long-lasting, and recyclable).

    1. Tony Salazar

      Wireless charging should be banned, if ever there is an innovation. It negatively influences the electromagnetic fields and causes a huge impact on the natures ecosystem. Birds will die.

    1. pointsnfigures tech is starting to become standard.

  24. Kirsten Lambertsen

    What if I could allocate a certain % of battery power to the different services on my phone? So, once that particular service hit its limit, that service would be turned off. That way the other low-battery-use services could keep going.Or, alternatively, just tell my phone that once I was at 20% battery, or whatever, to automatically turn off everything except x,y,z.

    1. Kirsten Lambertsen

      Ah, for iphone, there are apps for that, of course…

      1. Tony Salazar

        The problem is the common people would not understand the functions of battery charge allocations causing more confusion.

    2. Vasudev Ram

      That’s a good idea. There are existing technologies for similar needs (sort of) in computers – e.g. HP-UX (i.e. HP’s UNIX) had something called PRM – Process Resource Monitor, IIRC) and some mainframes, I’ve heard, have similar software, that allows allocating a minimum (and maybe maximum) percentage of system resources (like CPU, memory) to each of several running processes, to ensure that they are not starved of those resources due to too many process being run at the same time.

    3. LE

      A great idea. [1]Apple is resistant to things like this because they would feel that it would make things to “ungapotched” (yiddish: overdone) but it certainly makes sense. [2]You know it took car makers years to automatically time and shut off the headlights and/or interior lights (that you left on) so they wouldn’t drain the battery and not be able to start the car.[1] Reminds me of the Unix “nice” command.…[2] Or, alternatively, they have it planned and want to release it later in another OS or hardware. So there is motivation and an upgrade path for users.

  25. Mike Ajnsztajn

    There is a startup in NJ ,Sharewatts ,developing a technology that will enable the wireless transfer of electricity between mobile devices, including cell phones, laptops, and tablets.Do you want to know more? I can connect you with them.

  26. vruz

    I would like to have a solar wireless charger.Efficiency is a problem with wireless electricity, but if energy is basically free that’s less of an issue. Say if you’re a family of three, and if you had your solar wireless charger in the car, it doesn’t matter if battery charge time takes forever, as long as you can still use your devices until the next petrol station if you’re on the road.Mind you, it would enable for less bulky batteries, cheaper and lighter devices.People are just not thinking differently.

    1. Alex Murphy

      Goal Zero is awesome if you go camping / hiking. Charges a power cell during the day.

      1. vruz

        Which reminds me, petrol/gas stations should be renamed as energy stations.

  27. Tim Daubenschuetz

    I think this is a technical problem and will solve itself in a couple of years.With transistors getting less energy consuming and software getting optimized specifically to use less hardware on your phone the next 2-5 years will produce smartphones that last a full day/week of heavy usage.Why do I have this opinion?Because I’ve witnessed this progress myself using a Samsung Galaxy S3 and now a Oneplus One. Battery-wise they are years away from each other.Also: see Apple iOS’s low hardware consumption. This is the key to battery life.

    1. Kirsten Lambertsen

      Really starting to consider getting Oneplus One…

      1. Tim Daubenschuetz

        Get one! Best purchase decision for the last year or so, couldn’t be more pleased with the device.Its cheapness also frees you from the obnoxious dropping/loosing-your-phone fear.However, lets hope that Cyanogen and Oneplus continue to deliver first-class software…

  28. Wonyoung Kim

    My startup designs battery charger chips and other power related chips. Just to comment on several things:1) Transferring power from one phone to another phone will be pretty inefficient, which means the charging will be slow. Also, only certain phones can be the power source because you need a special chip for that feature. 2) Charging will be even slower when doing this wirelessly because wireless power transfer is even more inefficient. 3) I think the best approach (which Samsung is taking and others have started) is to make battery charging very fast so that just 5 min charging can give you 4 hours of usage. Most phones (except for iPhones) use the same micro-USB cables, so you could just borrow one from someone for 5 minutes e.g., at the airport. 4) Energy harvesting from solar and body heat has very low efficiency, so the charging speed is terribly slow. You’ll have to charge your phone for a couple of hours on direct sunlight to get to around 5% battery. Silicon solar cell efficiency has saturated at around 20% and has not been improving for years. Body heat is an even more inefficient power source. Both of them involve a lot of research and while I think there can be steady improvement, there cannot be a sudden breakthrough.

  29. pointsnfigures

    someday soon, you will be able to take your phone, put it on any surface and use to recharge it without a cord.

  30. LaMarEstaba

    I have an Everpurse (wireless charging) to prevent this from happening. My model has enough juice in it to recharge my iPhone fully twice. I used to carry a cord and have battery anxiety, but I don’t anymore. You have to make sure that the purse goes on the charging mat when you get home, but it’s better than before.

  31. amit kumar… I guess all discussions are by USA ppl who generally believe apple is the most innovative company. Let me change that. I own lenovo s860 mobile. It charges other mobile. Period.

    1. Ernest

      How’s Superfish performing πŸ˜‰

  32. OurielOhayon

    I wrote about this exact problem and solutions on my facebook page about a year ago. And some people answered it was possible to do it but required a different set of battery capability that would reduce the native lifetime of one s battery.

  33. YeahRight

    The most important problem of the 21st century: battery lifetime. πŸ™‚

  34. Jeff Chang

    Doblet (YC S14 – is putting portable app-driven batteries everywhere – in bars, restaurants, coffee shops, hotels, conference & festival venues – so that you can charge anywhere you happen to be.The two biggest issues are always 1) it’s too much hassle to carry a charging cable or to remember to recharge an external battery, and 2) most of the solutions on the market are these giant charging lockers, where you lock your phone away for an hour. The only reason you’re charging your phone is so that you can use it – seems counterproductive to lock it away in a metal box.We were just approved by Apple MFi last month as the world’s first ‘smart’ portable battery charger, and we’re now live in 50 venues across SF, with 20-30 new venues added each week. We’ve signed on just over 1000 venues in the Bay Area so far.It’s like a rideshare for batteries — for $30 a year, you get unlimited use of Doblets anywhere, charging your phone right when you need it most (or $3, for unlimited use for 24 hours). And the Doblet app can notify you when your battery is low, if there are Doblets within 2 blocks of where you happen to be.

    1. Josh Bruegger

      This is cool! What makes it fall into the ‘smart’ category though, maybe I’m missing it? I feel like I’ve heard of something similar, do you patent something like this, or I guess what’s patentable?

      1. Jeff Chang

        The Doblet’s controlled & managed by our iOS / Android app, so that we can really optimize your charging experience. It’s activated via the app — if you’ve got an annual subscription, it’ll activate automatically even in the background. We’ve been building our patent portfolio around the underlying technologies, implementation & venue experience, in conjunction with one of the best startup IP firms in the Bay Area. Hope that helps!

        1. Josh Bruegger

          Thanks Jeff! So what if folks leave with them? I’m the type to forget after stashing something in my back pocket or jacket..can you travel outside the venue with them or do you like check them out somehow like redbox?

  35. Dan B

    Battery sharing with payment in bigfoot for your battery?

    1. Dan B

      That should say bitcoin, lol — still getting use to my surface

  36. Dan G

    I’ve never ran out of power with my Moto X, but then anytime it’s convenient, it plug it into my power pack that I keep in my backpack.

  37. Alex Murphy

    Everyone should have a Mophie. Super fast charge.Also, Droid Turbo is awesome. Lasts all weekend without a charge.

  38. richardaltman

    Call Bram Cohen

  39. Gregg Freishtat

    While am 100% sure my battery “hard science” is not close to those in the field, it feels like this is close but not cigar. The little battery bricks out there are so good and so easy and carry a charge so long, I think a better questions is why doesn’t someone build a backpack or other “things” you have with you all the time that has deep battery reserve you can just charge up with int he places you are with the stuff you have. The battery of things I suppose. I use my brick all the time but the form factor sucks. No new tech required – just an elegant redesign of the awesome tech out there that is not form functional for how we live and move 2 cents after a round a golf and 4% charge left. I don’t want another phone to charge from – I want a clip on my golf bag to stay charged the whole day ….. and of course, everywhere else. A belt? Bet the soles of shoes could carry a mean charge…. who knows.Gregg F

  40. ShanaC

    You can buy a spare battery! (on my to do list)

    1. Philip Smith

      I have had a spare battery on most business trips for many years. I also tend to bring the adapter and plug the phone and when I have a spare minute. Despite this, I have still found myself running out of juice from time to time.

  41. Ranjith Kumar

    Battery charge is equal to the Gas in the Car. I have not known a concept of sharing Gas very much on the Road. The sharing of energy is very much dependent on the sharer’s plan till he gets the next charge point. So the better options is make the battery indicator apps better. The Battery apps should read the Phone calendar and know more about the Users plan and also should know the usage pattern of the User and warn him well before is there a need for him to charge it now. More inline with the Range indicator of the automobile but as the phones are smarter, they can warn the user when he is near a charging point or tell the user whether there is a need to carry power backup.Sharing however may work inside the family or close friends where indeed you could share your phones.

  42. James Ferguson @kWIQly

    Hi FredSimply there is a dilemmaIf you want to share between similar devices you can do so fast… but this ensures that you burn as much power in the transmitting device as you pass to the receiving device.Or you can share between very dissimilar devices (which can be very efficient – think power station downloads to phone charger) but it is inherently much slower. (The phone takes a zillionth of what the power station can offer)So if you and I have A and B spare charge in similar device we cannot get to A+B / 2 fastWe can only get to (A+B) LESS (A-B) / 2 fastif B is zero (your situation) you can get to a/2 shared equally or each having a quarter of what you started with. Each time you share you lose half of what you share in total.SO – It makes no sense for phone manufacturers to do this without very specific provisioning for alternative transfer infrastructure (which they call a charger)Electrical energy transmission is not very effective – better to unplug your battery and swap and you get double the benefit (but half the air-time each)

  43. Kevin Hill

    It is one more device, but I love my external battery pack for situations like this.

  44. Peter Gasca

    Why can’t they create a charger that doesn’t require hours to recharge? I know there is physics involved, not to mention economics, but can’t we all agree that quick charging would be worth the return on investment to productivity? Oh, and I love the idea of using body heat …

    1. PhilipSugar

      They do make quick rechargers but physics: the device is big and you have to be really careful about overcharging which is now much easier to do, not to mention you now have a really hot battery. They make them for LIPO batteries. We use them in robots. Problem: If you overcharge you can have a fire, and that fire is a serious matter. I have seen one.

  45. Evan Hill-Ries

    actually just bought one that’s designed for this; $150 for a 5000mAh battery (with a KitKat phone attached :P)…Does seem to need a USB OTG cable like the rest, though.

  46. Abdullah Alshalabi

    My cousin had this idea 3 years ago, we even planned how the video will look like in Kickstarter (one scene is you give your wife 5% then she finds out that you gave 10% to a girl at office and your wife go crazy and starts a fight! Because giving your battery shows how much you care for someone) and after lots of testing and trial and error he managed to get one phone to charge the other phone 1% in one hour! (if I remember correctly.) The phone didn’t have enough capacity to charge fast enough.

  47. Robert Metcalf

    There’s some physics that makes phone to phone charging difficult/slow: each phone, regardless of charge, is nearly the same voltage, so there’s no potential difference to drive the transfer. Phone batteries are generally in the 3.7 to 4.2 V DC range, and Li ion batteries have a relatively “flat” performance curve, in which their voltage diminishes very gradually, until it falls off a cliff (voltage vs depth of discharge).That’s why we charge from the wall at 120VAC through a transformer at 5VDC. As far as the phone is concerned, when connected to the wall it effectively has infinite potential and current to draw from, so its charging rate is internally limited by what the batteries and phone’s control logic will be happy with. If it were connected to another < 5VDC battery source, you’d become VERY good friends with the person you were connected to, because you’d be connected to them for a long time.I’d be happy to be wrong, but this seems inherently true from a first principles standpoint. Am I missing something?

  48. Mike

    Looks like you were only a day ahead of the times. The Neptune suite offers that functionality where peripherals can charge the Hub…

  49. Yunderson Labs

    in a dense urban area, doblet works well. but you’re speaking of a “free” native hardware/software feature, which is preferable.

  50. teance.gliese581d

    In china ,this product have considered . It’s called “FlashTip”, 1mm thin,only use 1x and throwaway, the battery power could be provide through or reach half a day, that is matured technologies ( Inkjet printing technology + Nanotechnology ), the planer calculate the cost of each “FlashTip” that it would costed $0.2 , and they want to sales on price $0.8 / eac . The team of R & D are chemistry students Fudan University, Shanghai , I have knew this from a ducument of a business plan that by downloaded online . If you are interesting, I’m willing to share this doc paper, but it’s all chinese worlds.

  51. Colin

    Back from 3 weeks in Asia, literally everyone has a mobile power bank. Xiaomi models are by far the most popular ( In my view if they marketed it right these are the devices that will gain Xiaomi a foothold in EU/US. In Hong Kong, street markets are selling knock-off Xiaomi’s. Shows how far China has come to see that in Hong Kong they are selling knock-off Chinese hardware…

  52. PhilipSugar

    See my comment. I have a prototype one. The problem is that little battery is hard to beat.