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Articles on laptop battery life focus on software tips. Those help, but the surest battery life improvements come from battery efficient hardware, not software tweaks. Unfortunately, finding laptops with awesome battery life can prove tedious.

Most manufacturers lie about battery performance. Some advertise times for idle battery life – or how long the laptop runs while not in use. Many don’t even bother listing how long the battery will last. Fortunately, smart buyers can gauge battery life if they know exactly which parts sip power and which absolutely drain it.

Seven components enable longer battery life: Hard drive technology, the CPU, the operating system, the battery, wireless technology, screen resolution and screen technology. If you want ridiculously long battery live, take a look at the primary components. Some can get upgraded for very little cost. Others you may get stuck with.

laptop power button

What Should You Look For In A Laptop For Longer Battery Life

If you want an executive summary, here it is:

  • Look for Solid State Drive technology from Samsung;
  • Look for Bluetooth 4.0 and Wireless-AC;
  • CPU performance-per-watt: Choose Haswell or Broadwell (due Q4, 2014) Intel CPUs with CULV technology or Core-M (due in 2014 Q4);
  • CPU battery life: Go with Intel’s Bay Trail-M technology;
  • Look for the latest in IGZO screen technology;
  • Lower resolutions require less energy;
  • Look for at least six cell batteries or at least 6,000 mAh packs in Ultrabooks and 4,000 mAh in Chromebooks;
  • Look for the latest nano-wire batteries.

For those seeking a more detailed explanation, please continue reading.

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Hard Drive Technology

There’s four kinds of drives used in modern laptops: Hard disk drives (HDD), solid state drives (what’s an SSD? How Do Solid-State Drives Work? [MakeUseOf Explains] How Do Solid-State Drives Work? [MakeUseOf Explains] Over the past few decades, there has been a considerable amount of work in the field of computer hardware. While computer technology is constantly improving and evolving, rarely do we experience moments where we simply... Read More ), hybrid drives and mini-PCIe solid state drives.

  • HDD: These are sometimes referred to as mechanical drives, because they use a number of moving parts. Because HDDs use moving parts, oftentimes their power requirements run high. They also fail at a very high rate (5 signs your hard drive might be failing 5 Signs Your Hard Drive Lifetime Is Ending (And What to Do) 5 Signs Your Hard Drive Lifetime Is Ending (And What to Do) Since a majority of people today own laptops and external hard drives, which get dragged around quite a bit, a realistic hard drive lifetime is probably around 3 - 5 years. This is an extremely... Read More ). The lower RPMs of 2.5-inch drives tend to require less power than 3.5-inch HDDs. While spinning up, hard disk drives can consume as much as 25 watts (or more). In general, HDDs use more power than SSDs.
  • SSD: SSDs offer (generally speaking) superior power consumption compared to traditional drives. Some SSDs include sophisticated internal components, similar in specification to smartphones. Other SSDs offer much lower drain characteristics. Keep in mind that most laptops offer upgradeable internal components – you can easily swap out a regular hard disk drive in exchange for an SSD. Just make sure to find the SSD’s wattage consumption, first.
  • Hybrid drives: Hybrid drives combine traditional hard disk drives with solid state drives. They run on the same SATA III channel, though, so the SSD and HDD compete for bandwidth with one another. On the positive side, when users install a modern operating system – such as Windows 8.1 – the core operating system files copy to the SSD portion of the hybrid drive, whereas it retains the storage capacity of a HDD. In theory, these offer the best of both worlds – in practice, hybrid drives tend to suffer from higher power consumption than other kinds of solid state drives.
  • mSATA SSD: mSATA SSD cards use a mini-PCIe-like SATA port. Tom’s Hardware reports that Intel mSATA SSDs consume the least amount of power at idle. For active use, however, they consume slightly more than average. mSATA cards are also electrically compatible with mini-PCIe ports, so they can plug into mini-PCIe, although their data transfer over the SATA host controller.

Best battery life: SATA-based SSDs tend to require less power than comparable technologies on the market. Samsung and Intel tend to push the envelope regarding SSD power consumption. Right now, according to Tom’s Hardware, the Samsung 840 EVO offers some of the all-around best (active and idle) battery performance measurements. It will save somewhere between 1 and 2 watts during active use and a tiny amount while idle. On the other hand, the recently released Samsung 850 Pro is rumored to possess special battery saving features. Anandtech rates the 850 as the third most efficient SSD.

solid state drive example

CPU Thermal Design Power (TDP)

Computer processors tend to consume a great deal of power. Manufacturers specify the higher limit of the wattage (and thus heat produced) produced by a laptop using a system called Thermal Design Power (TDP). TDP nominally equals the wattage used by the CPU at maximum heat output. In general, a CPU with lower TDP (measure in watts) will yield better battery life.

Intel

intel logo

Laptop CPUs run at lower frequencies than desktops – thus, they consume less power with diminished heat. Intel’s most used lower-voltage CPUs are CULV and M-series processors.

  • CULV: CULV processors come soldered to the motherboard in a configuration known as Ball-Grid Array (BGA). These consume less power, although their frequencies and cores often fall below that of an M-series CPU. Every generation of Intel CPU includes CULV variants, recognized by a “Y” or “U” appended on a processor model name. Most CULV CPUs consume between 14 and 25 watts.
  • Core-M: The Core-M series of processor operate below 10 watts, meaning they can result in fanless laptops. Intel stated that laptops would show up with Core-M prior to the holiday season. Core-M consumes around 4.5 watts — but it potentially hits 12 watts under heavy load.
  • M-Series: Intel has been pumping out M-series processors for quite some time. These tend to offer scaled down mobile versions of their desktop processors. If you prize battery life, the CULV processors tend to offer a better deal compared to M-series models. Most M-series CPUs consume between 35 and 55 watts.
  • Bay Trail-M: These (once referred to as “Atom”) processors feature performance on-par with AMD’s Kabini APU, using less than half the power. They operate fanless and with staggering battery efficiency. For example, Chromebooks using Bay Trail-M get over 9 hours of battery life. With a TDP of 7.5 watts, Bay Trail-M offers excellent performance for the wattage. In 2015, Bay Trail moves to a 15nm production process (code-named “Braswell”), meaning even greater power efficiency.

AMD

amd logo

AMD’s latest APU (what’s an APU? What Is An APU? [Technology Explained] What Is An APU? [Technology Explained] Read More ) designs branch out into three groups: Its A-series processors, which are based on the latest Kaveri architecture (with exceptions), and its Mullins and Beema APUs. While Mullins seeks a home inside of tablets, Beema might see limited use inside of low-end notebooks. TDP generally hovers around 10 watts, making it suitable for fanless operation.

  • Kaveri mobile APU: AMD’s latest CPU architecture, Kaveri, offer TDP ratings from 17 to 35 watts. In general, the TDPs run lower than Intel’s, but overall performance per watt falls squarely in Intel’s lap. When it comes to mobile gaming, AMD comes out ahead (ignoring Intel’s Iris Pro) in terms of performance-per-watt.
  • Beema: Beema aims at lower-end notebooks. It includes TDP ratings between 10 and 15 watts. It could possibly support fanless laptops, although most models will most certainly use some form of active cooling. Because Beema targets low-end devices, most manufacturers will reduce the size of the battery, offsetting Beema’s low power consumption.
  • Mullins: Mullins aims primarily at the tablet market. It also offers quad-core variants, with a TDP at 4.5 watts. Its overall performance doesn’t compare to Intel’s Broadwell-based Core-M.

Lowest Power CPU: If early reports possess credibility, Intel comes out ahead in performance-per-watt for its upcoming Core-M CPU. Not only does the processor enable fanless laptops (which further extends battery life), it should perform similarly to CULV Haswell mobile processors. If you prefer a budget model, Intel’s Bay Trail-M (Celeron/Pentium) lines of CPU will offer extremely good battery life with a low price-point.

intel cpu processor

Operating System

Operating systems require extensive optimization on a laptop-by-laptop basis to get better battery life.

Out of the major operating systems, ChromeOS offers the best battery life. After that, Windows 8.1 and OS X tend to offer better battery life than user-installed Linux. It’s been reported that OS X offers better battery life than Windows. A lack of driver support and unoptimized default settings seem to cause Linux’s battery life woes. Linux also possesses a surprising number of battery optimizations PowerTOP Will Maximize Your Linux Laptop's Battery Life PowerTOP Will Maximize Your Linux Laptop's Battery Life On Linux laptops, one of the most common complaints is that the battery life isn't that great. You can find out what settings are best for your system using PowerTOP. Read More , which are very technical. Users can fix some of Linux’s battery problems Easily Increase Your Battery Life With TLP for Linux Easily Increase Your Battery Life With TLP for Linux Linux tends to guzzle up more battery life than Windows, even though most Linux installations are lighter than Windows on system resources. Why is that? Read More , but not all.

Best battery life: ChromeOS offers the best battery life, but at the cost of software compatibility. Windows 8.1 and OS X offers good battery life and a larger software library. In general, Apple produces the most efficient laptops than comparable designs from Windows manufacturers, with a steep price-premium.

chromeos

Battery

Most laptop manufacturers don’t state the total amount of energy stored within a battery. Some list the total number of cells used, which commonly run from three to nine cells. In my experience, the term “cell” refers to the number of 18650 form-factor batteries contained within a battery pack. For example, a six-cell laptop battery contains six 18650 batteries. The mAh rating of each 18650 battery within the pack can vary, but most offer around 1,800-3,000 mAh. Most quality 18650s originate from Samsung, Sanyo, Sony or Panasonic.

18650 battery

Lithium-ion batteries with a graphite anode will soon get replaced by an upcoming technology. As of 2014, two new kinds of battery technology exist, which increases battery longevity, recharge speeds and energy density. The technology, nano-wire batteries, use either a “crushed” silicon or germanium anode. The theoretical energy capacity hovers around 10 times greater than current graphite anode technology. However, early production models boost energy capacity by 20-40%.

Unfortunately, as battery technology improves, laptop manufacturers prefer shrinking the size of the battery. When manufacturers moved from cadmium to lithium-ion technology, laptops didn’t gain much in terms of battery life – they just became sleeker. But if we were to take a standard six-cell battery with around 12,000 mAh and swap in silicon anode 18650 batteries, we would see mAh ratings somewhere between 14,400 and 16,800 mAh. Because 18650 batteries may eventually see silicon nano-wire technology, it’s conceivable that DIY-ers could swap such technologies into their current laptops.

Best Battery Life: Without question, silicon-anode batteries will revolutionize laptop battery technology. Companies are already selling the technology on a select number of devices. The Ubuntu Edge smartphone was slated to receive it. Those wanting better battery life should look for these batteries soon.

Wireless Technology

The majority of budget laptops package wireless-N (802.11n) with Bluetooth 3.0 modules. The older standard drains quite a bit, using something on the order of 6-watts per hour. The latest standard in wireless connectivity is Bluetooth 4.0 and wireless-AC (802.11ac). 802.11ac and Bluetooth 4.0 place a great deal of emphasis on power efficiency.

WiFi and Bluetooth tend to comprise the largest amount of drain for most systems. Most budget models of laptop include user-replaceable cards which package both Bluetooth and WiFi into the same unit. However, the newer 802.11ac WiFi standard and Bluetooth 4.0 offer dramatically decreased impact on your laptop’s battery life. On the downside, they both require compatible devices before their efficiencies can be realized.

Best battery life: Don’t settle with older mini-PCIe cards that package Bluetooth 3.0 and 802.11n standards. You can improve power efficiency and performance by either upgrading or buying a unit with the newest standard.

2014-08-02_19h52_10

Laptop Screens

Screen Technology

To my knowledge, the only commercially available alternative to standard LCD screens is the IGZO (indium, gallium, zinc oxide) technology, from Sharp Electronics. IGZO screens come with extraordinary screen resolutions (3200 x 1800), along with much lower battery drain. It’s reported that the screens use 57% less power than traditional LCD screens. It’s already in a number of laptops, such as the Dell XPS 15 and the 2014 Razer Blade, although these tend to run between $1,500 and $2,000.

The Kindle Fire uses an alternative technology, known as LTPS – it drains 30% less than IGZO screens but likely won’t see wide adoption as it costs a great deal more. It’s unlikely that we’ll see LTPS laptop screens.

Best battery life: IGZO screens will offer the longest battery life, along with ridiculously high resolutions.

Screen Resolution

Higher resolution screens drain a great deal more than lower resolution ones. You can manually reduce your screen’s resolution for increased battery life, although most users would benefit from simply reducing screen brightness.

Best battery life: Lower resolution screens drain less.

My Ideal Laptop

As a thought experiment, I put together a parts list for a theoretical laptop that uses powerful components combined with energy saving internal parts – I also make a wattage calculation to show theoretical battery life.

  • Hard drive: Samsung 850 Pro SSD
  • CPU: Intel Core-M CPU (Broadwell-Y)
  • Wireless Card: Intel 7620 Bluetooth 4.0 and 802.11ac
  • Screen technology: 3200 x 1600 IGZO display monitor
  • Battery: 6-cell lithium-ion with silicon nano-wire anode (around 15,000 mAh)

I’ve read that the average laptop consumes around 17 watts under moderate load. Using various battery-optimizing technologies, a laptop can use as little as 10 watts when in use. Combined with an Amprius battery that’s 20-40% more energy dense, a laptop could get up to 15 hours of actual use, with all radios turned on.

The computer most likely to receive many of these technologies is the 2015 MacBook Air. Chromebooks might also eventually show up with most of these technologies.

Conclusion

The two most important laptop components for battery life: The screen and the CPU. Neither component can upgrade with ease so these remain critically important at the time of purchase. The hard drive, wireless card and battery can potentially upgrade to a better standard. However, not all laptop manufacturers provide upgraded battery packs – so you may also want to pay close attention to the number of cells contained within the battery pack.

If you prefer longer battery life for your laptop, look for low TDP CPUs, a large number of battery cells (at least 6 cells), Bluetooth 4.0, Wireless-AC, lower resolution screens and (at best) IGZO screen technology. For Ultrabooks, check for at least 4,000 mAh batteries.

Anyone know of any other battery-saving technologies? Let us know in the comments.

Image credit: Laptop Power Button via MorgueFile.com

  1. Richard
    November 11, 2016 at 11:16 am

    Comparing your ideal laptop to my Lenovo P50: "Hard drive: Samsung 850 Pro SSD" -> 950 Pro NVMe; "CPU: Intel Core-M CPU (Broadwell-Y)" -> Xeon E3-1505Mv5 Skylake "Wireless Card: Intel 7620 Bluetooth 4.0 and 802.11ac" -> 8260 "Screen technology: 3200 x 1600 IGZO display monitor" -> IGZO 3840 x 2160 "Battery: 6-cell lithium-ion with silicon nano-wire anode (around 15,000 mAh)" -> Not sure how many cells, but 90Wh and over 6 hours of battery life.

    Hey - looks like the P50 is way better than your ideal laptop. :-)

    • Kannon Yamada
      November 12, 2016 at 7:45 pm

      Hi Richard, thanks for the comment!

      This article REALLY needs an update. There's a few things that I haven't included that need to be mentioned, like Panel Self-Refresh compatible panels (most IGZO screens are also PSR compatible).

      Right now the FHD Dell XPS 13 can get 18 hours of battery life, if you try to hyper-mile it. It uses PSR, IGZO, and a large (for its class) battery.

      You have a fantastic laptop, by the way.

  2. Scott H
    August 31, 2015 at 2:06 pm

    I'd like to make one note on the power consumption of SSD vs HDD.
    While it is true that SSDs use less power than mechanical drives when the laptop is new, over time, much/all of those performance gains are lost.

    SSD are volatile so over time, data can literally evaporate. To compensate, when idle, SSDs will periodically overwrite the data to freshen it and prevent it from being lost. As you add more data over time, the drive spends more time rewriting itself, using more and more power and 'evaporating' the supposed power-sipping of SSDs.

    • Kannon Yamada
      August 31, 2015 at 3:24 pm

      That's interesting, thanks for sharing! Only some of this information is known to me.

      I thought one of the issues with SSDs is that they don't rewrite data, which is why they begin degrading over time. For example, Samsung TLC SSDs suffer from varying degrees of read speed decline, depending on the nanometer production process used in their NAND packages. The smaller the production processes, the faster the current leaks. The smallest 19nm NAND begins decaying after 9 weeks. The older 21nm NAND begins decaying at around 40 weeks.

      I had no idea that SSDs periodically rewrote data, although that makes sense, since all magnetic or electric signals degrade over time. Even data on the platter decays over time.

  3. Shivam
    October 25, 2014 at 1:00 pm

    wanted your review on lenovo y510...actually i'm a undergraduate student and looking to buy something powerfull and classy....i'm really concerned with its battery performance

    • Kannon Y
      January 11, 2015 at 4:58 am

      Shivam, that's a multimedia machine. Basically, they cram relatively powerful GPUs into those things and it tends to impact battery life severely. If you aren't into gaming, check out the 2015 Dell XPS 13, which appears to combine all the technologies I've spoken of into a single package: http://www.dell.com/us/p/xps-13-9343-laptop/pd

      At CES it was probably the best regarded laptop.

      It also is on sale right now and students get an additional 10% off. You just have to find the coupon code. I just got one for $710 along with $35 in credit card discounts and another $35 in Dell gift cards.

  4. Charlie
    August 13, 2014 at 9:45 pm

    Thank you Kannon for responding
    Oh boy ! NOW I am in trouble given what you stated cause the "Dell Mode" keeps it fully charged at 100%, unless sometimes it shows say 75% and "not charging". Dell technical support is hopeless cause all they have is a cheat sheet to follow but they are not technically prepared to think in technical terms. So i wont take "my sheep to their wolf" so to speak. I will have to do some trial and error with all the available modes and see which sounds better in terms of extending the longevity of the battery itself.... not the charge but the integrity of the battery.

    if i want to keep the laptop plugged permanently to the wall -which i do-, I do not want to unplug it to allow the battery charged level down to 7% left which is the threshold Dell recommends to start recharging it again.I see from your response that it is not good for the battery life to tend to have it permanently charged 100%

    What do you think?

    Thanks again

    • Kannon Y
      August 30, 2014 at 11:16 pm

      Hey Charlie, sorry about the late reply. It appears that our commenting system ate my last response.

      I wouldn't worry too much about this particular issue, as replacement batteries tend to run around $30 on eBay (these are poorer quality batteries sometimes). Also, it takes a fair amount of abuse to permanently damage a battery. The worst thing you can do is drain a battery and leave it sitting around for months at a time. Filling it to 100% capacity isn't great as it will accelerate the battery's demise - but it's better than draining it all the way down.

      I would suggest either keeping it in your computer as an uninterruptable power supply and purchasing a replacement in a couple of years. Or leaving it at around 50-80% charged, unplugging it, and recharging it every month or two.... to around 50%-80%. Whichever one strikes you as a better choice.

  5. pmshah
    August 12, 2014 at 7:48 pm

    "The total mAh is equal to the number of cells, multiplied by each cell’s mAh rating."

    You are very sadly mistaken. With series connected batteries (as they most probably are in this case) you multiply the voltage with number of cells to get the output voltage. mAh rating will remain constant regardless of number of cells. What will actually change with number of cells is the output voltage and mWh rating. Please do get your units right.

    Not as a rule but as a practice you do not connect batteries in parallel. If you do you are looking for disaster in the making. It may be ok, just may be, for low power primary cells but very definitely NOT OK for secondary cells with low source impedance.

    • Kannon Y
      August 12, 2014 at 8:45 pm

      Thanks for the correction. Strange enough, you've saved me from making a grave error on a future project that I was still drafting ideas for.

  6. Saad Husain
    August 12, 2014 at 5:38 pm

    Don't forget that you turn off peripherals if you are not using them:
    USB Ports, Network Port, Bluetooth, WiFi (e.g. if you are flying for many hours) and have screen dimming after a few minutes.

  7. Roy
    August 12, 2014 at 5:25 pm

    Charlie, just take the battery out of it as whatever you do if it's always plugged in you'll kill it anyway!

    • Charlie
      August 13, 2014 at 9:55 pm

      Hi Roy, thank you for your comment.

      So let me see if I understand you. Rechargeable Laptop Batteries always die? Is it only a matter of when then?
      I had never thought to remove the battery. So you are saying that for my use I would be better served just to remove the battery and then the Laptop would behave just like a desktop with reference to Power Usage? The battery gets bypassed as it is not in there, and there is no interrupted power circuit then? The Laptop itself would not be harmed in any way without the battery?. As Laptops are designed for battery usage, they do not need the battery as a cushion/bumper or a filter for the 110 Volt from the mains?
      As you see little technical knowledge about how things work in the electronic side, just trying to use a little common sense to figure out the most basic of things
      I would appreciate clarification over this.

      Thank you kindly

    • Roy
      August 14, 2014 at 6:53 am

      No the laptop would be fine, there are lots of old laptops that run only on mains due to the battery condition. The reason for me suggesting this is that if you leave it in, it will constantly charge (top off) the battery so only the top gets charged, this kills the top of the cell and as it progresses more of the battery dies until windows tells you to replace it!

      Even if you used it, ie unplugged your laptop and let the battery run down then charged it (I'd advise this as you'll get the best when it does move!), you will only get a finite life anyway, hence why they are consumables and not covered under any guarantee!

      In short - if it's NEVER going to move! remove the battery after it's first 16hr charge, then charge again every few months - it will work when you sell it!

      If there's a chance it could move, ie round the house then just unplug it and "exercise" it, this will ensure good battery life

  8. Charlie
    August 12, 2014 at 5:07 pm

    I have a request for Kannon Yamada.
    My Dell Inspiron 3721 Laptop has been purchased exclusively to behave as a Desktop Replacement. If it is plugged to the wall almost always, this article is mostly not applicable. Am I right? I was told by Dell's techs to either have it set in Dell Mode or in Balance Mode to extend the life of the physical ion battery itself.
    I would be interested in reading your answer to this.

    Thank you

    • Kannon Y
      August 12, 2014 at 7:30 pm

      Hey Charlie, thanks for the comment!

      If you purchased the laptop without concern for battery life, you won't have to worry too much about how power efficient your laptop is. It's already a lot more efficient than a desktop and probably pulls something like 17-35 watts while in use. That's about half the power consumption of a light bulb.

      I would guess that Dell Mode or Balance Mode are designed to extend the life of your battery by not keeping it fully charged, or cycling the battery. Both are great ways to keep the battery in good condition for a longer period of time. When a battery is fully charged, it expands slightly and the anode begins degrading faster than if it were at 50% charge. If the battery fully discharges, the anode will degrade at an even faster rate. For short periods of time, a fully charged or discharged battery won't degrade all that much - but for days or weeks at a time, it will cause significant amounts of damage.

      But anyway, don't worry about my article. You should be okay with what you have. Although you may want to consider Roy's advice (see below). If you want to use the battery as an uninterruptable power supply (in case of power failure) keep it in. If you want to occasionally use it for mobile purposes, you may want to keep it 50-80% charged and occasionally plug it in to keep it from discharging.

  9. Zhong J
    August 12, 2014 at 4:38 am

    This article wouldn't apply for desktop users will it? Of course, you can save your energy bill if you follow those guidelines.

    • Kannon Y
      August 12, 2014 at 9:22 am

      Thanks for the comment Zhong!

      This actually does apply to desktop users - IGZO technology should already be available on desktop monitors (but it's far more expensive), and Bay Trail is already available for the desktop. However, Core M CPUs likely won't see much use on the desktop, other than in perhaps Chromeboxes and perhaps BRIX units.

      Unfortunately, the low-energy desktop market is pretty limited. It would be nice seeing more low power parts though.

  10. Johnnie adepegba
    August 11, 2014 at 2:36 pm

    Hi, love your amazing detailed analysis. Pls, can you provide list of laptops with best battery life according to your assessments with or close to all that you've listed out, Plssssss!!!. Will be glad if you can, and if you can mail me laptops with best battery life...johnnieadepegba@gmail.com

    • Kannon Y
      August 14, 2014 at 12:56 pm

      Thanks Johnnie - are you looking for a laptop with Mac, Windows or ChromeOS? Or Linux?

      Right now Chromebooks are the hottest machines for long-term battery life, but they don't offer the same software as mainstream operating systems. Google's battery life estimates are also more accurate than those offered by most manufacturers. Most of the new models from Asus in the 13.3" form factor include Bay Trail CPUs, making them good for most simple tasks with 11-13 hour battery lives.

      Macs tend to offer the second longest battery lives. The Macbook Airs are among the best around. Thinkpads with U or Y-branded Intel CPUs are right up there, too. Workstation class laptops are often pretty good for battery life and performance.

      Anyway, let me know what operating system you're looking for and I'll give you a top three list.

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