Author: angel

Outside of its mobile-workstation-grade machines, Lenovo already has a “Think”-branded laptop aimed at creative professionals: the ThinkPad X1 Extreme, which competes with elite systems like the Apple MacBook Pro 16, the Dell XPS 15, and the Gigabyte Aero 15 OLED. But kit those machines out, and all cost more than $2,000—way more, in the case of the $3,899 Apple and the near-$4,500 HP ZBook Create G7. Lenovo’s small-business-minded ThinkBook 15p (starts at $954.85; around $1,350 as tested) offers creative power and a handsome 4K display at a considerably lower price. Its CPU and GPU aren’t the absolute fastest in its class, but it’s a great value for designers and video editors on a budget who don’t need all the deep manageability and security of a top-end ThinkPad. 

A Top Value in Two-Tone Aluminum 

The ThinkBook 15p doesn’t qualify as a mobile workstation because it has Nvidia GeForce rather than Quadro graphics, and it lacks independent software vendor (ISV) certifications for specialized design, rendering, and scientific apps. And it doesn’t match the ThinkPad X1 Extreme for a host of reasons. For one, it hasn’t passed MIL-STD durability torture tests as ThinkPads have. Also, its screen uses IPS instead of the more brilliant and expensive OLED technology, and it has no Thunderbolt 3 or 4 port for exotic drive arrays or external graphics. Furthermore, its processor lacks Intel’s vPro manageability for corporate IT departments.

But our test model 20V30020US—between $1,300 and $1,400 at etailers like Walmart, Newegg, and CDW at this writing—is nevertheless a bargain. It gets you a six-core Intel Core i7-10750H CPU, 16GB of memory, a 512GB NVMe solid-state drive, 4GB GeForce GTX 1650 Ti Max-Q graphics, a 3,840-by-2,160-pixel non-touch screen, and Windows 10 Pro. Also at this writing, the only configuration at Lenovo.com offered inferior (Core i5, 256GB SSD, 1080p) hardware for a higher “web price” of $1,469, though it was on sale for $954.85. So, like with many Lenovo and competing laptops, you may find the pricing fungible when you look.

At 0.78 by 14.1 by 9.8 inches, the ThinkBook is a match for the Gigabyte Aero 15 OLED (0.78 by 14 by 9.8 inches), though a few grams lighter at 4.2 pounds. The Dell XPS 15 is a bit more compact, at 0.71 by 13.6 by 9.1 inches and 4 pounds. Its aluminum case features two shades of gray with monochromatic Lenovo and ThinkBook logos (no flashy chrome) on the lid.

The 15.6-inch screen has medium-thin side borders and thicker top and bottom bezels. The top bezel holds a webcam with a sliding privacy shutter. The camera lacks face-recognition capability, but the power button doubles as a fingerprint reader for Windows Hello. (You can turn the PC on and sign in with one press.)

We’re disappointed to see an over-$1,000 laptop without a Thunderbolt 3 or 4 port, but the Lenovo otherwise offers good connectivity. On the left are HDMI and Ethernet ports, USB 3.2 Type-A and Type-C ports, an audio jack, and the connector for the AC adapter. Another USB-A port, an SD card slot, and a security-cable locking notch are on the right. Wi-Fi 6 and Bluetooth are standard.

One of the Brightest 

We hope to see 400 nits of brightness from a laptop screen but often settle for 300, so the ThinkBook’s 600-nit panel is a sunny surprise—it’s one of the rare displays that doesn’t look dim if you dial the backlight down a few notches.

Colors from this screen are rich and well saturated—the company says the screen is calibrated to 100% of the Adobe RGB gamut—and contrast is high. Wide viewing angles and crisp details, thanks to 4K native resolution, add to the appeal.

If the screen is a match for its ThinkPad cousins (well, all but the OLED models), the keyboard falls a bit short of that standard. On the upside, the key backlighting is bright, and the numeric keypad and top-row shortcut keys are handy. (The latter bunch includes microphone mute, video call start and end, and access to online support.) The typing feel is snappy, if a bit shallow. A smallish, buttonless touchpad glides and taps smoothly and takes gentle pressure to click. 

On the minus side, you must team the Fn and arrow keys in key combinations to make up for the absence of dedicated Home, End, Page Up, and Page Down keys. Also, the cursor arrows are in the clumsy row I eternally excoriate on HP laptops—with half-size up and down arrows sandwiched between full-size left and right—instead of the proper inverted T.

The 720p webcam captures reasonably well-lit and colorful images, but its focus isn’t sharp and there’s a bit of digital noise. Bottom-mounted speakers produce adequate audio, not particularly loud and missing bass but with clean highs and midtones; you can make out overlapping tracks clearly enough. Dolby software lets you choose music, movie, game, or voice presets or play with an equalizer. 

A Lenovo Vantage utility centralizes system-update and security options and hardware settings. Lenovo preloads a McAfee LiveSafe trial and backs the ThinkBook 15p with a one-year warranty. 

Performance Testing: Creative Pros Compete 

In constructing our benchmark charts below, I chose the MSI Prestige 15 so the ThinkBook 15p wouldn’t be the only contender with a six-core processor. (That said, the Prestige uses a U-series low-power chip, versus the ThinkBook’s heavier-hitting H-series.) The Apple MacBook Pro 16, the Dell XPS 15, and the Gigabyte Aero 15 OLED XC all have eight-core CPUs (and the last has a mighty GeForce RTX 3070 GPU that makes it the overdog in our graphics tests). All have high-resolution screens—4K for the ThinkBook, the Prestige, and the Aero; 3,840 by 2,400 pixels for the Dell; and 3,072 by 1,920 for the Apple. You can see their basic specs in the table below. 

Productivity and Media Tests 

PCMark 10 and 8 are holistic performance suites developed by the PC benchmark specialists at UL (formerly Futuremark). The PCMark 10 test we run simulates different real-world productivity and content-creation workflows. We use it to assess overall system performance for office-centric tasks such as word processing, spreadsheet work, web browsing, and videoconferencing. PCMark 8, meanwhile, has a storage subtest that we use to assess the speed of the system’s boot drive. Both yield a proprietary numeric score; higher numbers are better. (See more about how we test laptops.)

All four Windows laptops breezed past the 4,000 points that indicate excellent productivity in PCMark 10—they’re overkill for Word, Excel, or PowerPoint. Today’s swift SSDs all deliver similarly fast results for everyday tasks in PCMark 8’s storage measurement.

Next is Maxon’s CPU-crunching Cinebench R15 test, which is fully threaded to make use of all available processor cores and threads. Cinebench stresses the CPU rather than the GPU to render a complex image. The result is a proprietary score indicating a PC’s suitability for processor-intensive workloads. 

Cinebench is often a good predictor of our Handbrake video editing benchmark, in which we put a stopwatch on systems as they transcode a brief movie from 4K resolution down to 1080p. It, too, is a tough test for multi-core, multi-threaded CPUs; lower times are better. 

Six processing cores are rarely a match for eight, but the ThinkBook acquitted itself well in our processing tests. It can’t keep up with the fastest workstations, but it won’t make you wait impatiently for media editing operations. 

We also run a custom Adobe Photoshop image-editing benchmark. Using an early 2018 release of the Creative Cloud version of Photoshop, we apply a series of 10 complex filters and effects to a standard JPEG test image. We time each task and add up the total. (Lower times are better.) The Photoshop test stresses the CPU, storage subsystem, and RAM, but it can also take advantage of most GPUs to speed up the process of applying filters. 

The Lenovo wasn’t the quickest laptop ever to complete this exercise, but its brisk performance combines with its bright 4K screen to make it a first-rate image editing platform. 

Graphics Tests 

3DMark measures relative graphics muscle by rendering sequences of highly detailed, gaming-style 3D graphics that emphasize particles and lighting. We run two different 3DMark subtests, Sky Diver and Fire Strike. Both are DirectX 11 benchmarks, but Sky Diver is more suited to laptops and midrange PCs, while Fire Strike is more demanding and lets high-end PCs and gaming rigs strut their stuff. 

The Gigabyte’s bleeding-edge GeForce RTX 30 series GPU predictably clobbered the competition in this gaming simulation, but the ThinkBook can deliver decent gameplay at 1080p resolution. 

Next up is another synthetic graphics test, this time from Unigine Corp. Like 3DMark, the Superposition test renders and pans through a detailed 3D scene, this one rendered in the eponymous Unigine engine for a second opinion on the machine’s graphical prowess.

With the Dell balking at this test and the MacBook Pro not running our Windows benchmarks, we have only three sets of results to compare. The Lenovo edged out the last-place MSI, far behind the overpowering Aero but fast enough to handle a little after-hours gaming if you’re so inclined. 

Battery Rundown Test 

After fully recharging the laptop, we set up the machine in power-save mode (as opposed to balanced or high-performance mode) where available and make a few other battery-conserving tweaks in preparation for our unplugged video rundown test. (We also turn Wi-Fi off, putting the laptop into airplane mode.) In this test, we loop a video—a locally stored 720p file of the Blender Foundation short film Tears of Steel—with screen brightness set at 50 percent and volume at 100 percent until the system quits. 

Can a ThinkBook Undercut a ThinkPad? 

The much-better-equipped ThinkBook 15p available from a host of online retailers, with a lower price than the model at Lenovo.com, is quite a find, and the 15p as a whole is good enough to make buyers considering a ThinkPad X1 Extreme think twice.

Since it’s intended for content creators, its poor support for multiple monitors is a minus—there’s an HDMI port, but no Thunderbolt connectors, and the USB-C port lacks DisplayPort functionality—but its own screen is extremely attractive. The ThinkBook comes up shy of Editors’ Choice honors, but it is well worth a look from wallet-conscious creatives who need a bright, color-accurate screen, a little GPU muscle, and H-series CPU power at a midrange-laptop price.

Lenovo ThinkBook 15p Specs

Laptop Class	Business, Desktop Replacement
Processor	Intel Core i7-10750H
Processor Speed	2.6 GHz
RAM (as Tested)	16 GB
Boot Drive Type	SSD
Boot Drive Capacity (as Tested)	512 GB
Screen Size	15.6 inches
Native Display Resolution	3,840 by 2,160
Touch Screen	No
Panel Technology	IPS
Variable Refresh Support	None
Screen Refresh Rate	60 Hz
Graphics Processor	Nvidia GeForce GTX 1650 Ti (Max-Q)
Graphics Memory	4 GB
Wireless Networking	802.11ax (Wi-Fi 6)
Dimensions (HWD)	0.78 by 14.1 by 9.8 inches
Weight	4.2 pounds
Operating System	Windows 10 Pro
Tested Battery Life (Hours:Minutes)	11:07

It seems whenever you need a certain type of battery at home, it’s always the one you’re out of. When you run to the store, you find a lot of choices and different prices.

But before you buy any batteries, you need to know a few things. First, there are two types of batteries: alkaline and lithium. More to the point, not all batteries are a good value. Does paying more mean you’ll get a better, longer lasting battery?

No, not according to tests from Consumer Reports. They tested 15 brands of AA batteries, including Amazon-branded batteries and Costco’s Kirkland batteries, to see which ones came out on top in the past.

The prestigious magazine found previously that some lower-cost batteries are just as good or nearly as good as the most expensive brands. In fact, you’ll be shocked by how you don’t need to break the bank for high-quality batteries that will keep your Christmas presents humming for weeks or months.

Note: Consumer Reports previously tested batteries in two ways: They used the batteries until they died in toys for one hour a day and in flashlights for four minutes every eight hours. They no longer test batteries, however, but their findings still hold true – you can get some great batteries without having to break the bank, depending on which brand you use.

Alkaline vs. Lithium

First things first. You’ve probably noticed that generally speaking, lithium batteries are expensive.

You might be tempted to buy them, thinking that if they cost more they probably last longer. As it turns out, Consumer Reports has suggested in the past to use lithium batteries sparingly, like in devices that need a quick burst of power or that you don’t use very often.

Note: You can store lithium batteries for up to 15 years. They don’t need to be stored in the refrigerator and they don’t usually spew liquid like older, carbon-zinc batteries did.

Some alkaline batteries performed as well as lithium batteries in the same previous Consumer Reports test. These batteries are typically less expensive. You may want to use them in devices you use a lot, like your TV remote control and your computer’s wireless mouse.

Best value

So, which brands performed best in Consumer Reports’ tests? Both alkaline and lithium batteries were among the best values.

This might surprise you. The top performers included two brands that might have the perception of being “cheap.”

Costco’s Kirkland Signature brand AA alkaline battery had an overall score of 80, out of a possible 100. Unfortunately, while they remain the highest-scored product in terms of branded store batteries, they have since gone up in price – Duracell raised its prices and passed them on to Costco on its private branded products, and that’s what the Kirkland Signature batteries are, after all. They aren’t the best deal any longer, but they still performed the best at the time of this test.

Meanwhile, AmazonBasics Performance AA Alkaline scored a 71 on the original test.

That compares to top-rated brands such as Energizer Ultimate Lithium AA (89), Duracell Quantum AA Alkaline (89) and Rayovac Fusion Advanced AA Alkaline (85).

There are other great deals you can find as well, however, on batteries that weren’t included in the test. For instance, you can check out the Dollar Tree deal on four Sunbeam batters for a $1 a package, which makes them 25 cents apiece. Additionally, Tenergy batteries make for great choices.

Here’s the full list of the most recent Consumer Reports test for your reference:

Lithium batteries

• Energizer Ultimate Lithium AA – CR only tested two lithium batteries and this one came out on top. It received an overall score of 89.
• Energizer Advanced Lithium AA – This one came in second with an overall score of 82.

Alkaline batteries

• Duracell Quantum AA Alkaline – CR tested a total of 13 alkaline batteries and this one is the best. It received an overall score of 89.
• Rayovac Fusion Advanced AA Alkaline – Overall score of 85.
• CVS Max AA Alkaline – Overall score of 82.
• Duracell Coppertop Duralock AA Alkaline – Overall score of 80.
• Kirkland Signature (Costco) AA Alkaline – Overall score of 80.
• Rite Aid Home AA Alkaline – Overall score of 79.
• AmazonBasics Performance AA Alkaline – Overall score of 71.
• Walgreens W Alkaline Supercell AA – Overall score of 71.
• Energizer ecoAdvanced AA Alkaline – Overall score of 68.
• Energizer MAX +PowerSeal AA Alkaline – Overall score of 67.
• CVS AA Alkaline – Overall score of 62.
• Dynex (Best Buy) High Capacity AA Alkaline – Overall score of 60.
• EcoAlkalines AA Alkaline – Overall score of 59.

How to store and use batteries

When you’re not using a device very often, take out the batteries. It’s best to store them in a cool, dry place.

You may also want to wipe off the batteries before you put them into a toy or gadget. When you can, use the same type of battery and brand when you’re using more than one AA battery.

Be careful, too. Keep batteries away from children, including tossing old ones in the trash.

Choosing the right battery

A battery is a device composed of one or more electrochemical cells with external connections to power electrical devices. In this guide we will cover all types of rechargeable batteries as well as non-rechargeable (alkaline) technology.

Rechargeable batteries come in many different shapes and sizes, ranging from button cells to megawatt systems connected to stabilize electrical distribution networks. Several different combinations of electrode and electrolyte materials are used, including lead acid, nickel cadmium (Ni-Cd), nickel metal hydride (NiMH), lithium ion (Li-ion) and lithium ion polymer (Li-ion polymer).

How to choose a battery?

When choosing a battery, you should take the following characteristics into account:

• The battery capacity in milliampere-hours (mAh) (calculation method provided below).
• The voltage, which is dictated by the materials used for the electrodes and can range from 3.2 to 4 V for lithium batteries and from 1.2 to 2 V for others.
• The operating temperature.
• The size and shape of the battery.
• The type of use.
• The price.

All batteries have two common characteristics:

• Their voltage, expressed in volts (V): rechargeable batteries are generally 12 V. For larger cells with voltages of 12 V, 24 V or 48 V, separate 2 V cells are used, intended to be assembled in series, and which have a lifespan of about 10 years.
• Their capacity, expressed in ampere-hours (Ah): to increase it, several batteries must be connected in parallel.

When you multiply the voltage by the capacity, you get the amount of electricity stored in kilowatt-hours (kWh). For example: A 12 V – 100 Ah battery theoretically contains 12 x 100 = 1,200 Wh = 1.2 kWh.

Depending on these characteristics, you will have to choose the technology, or battery type, and chemical composition: lead-acid, nickel or lithium. There isn’t one battery technology that’s better than the others. Each type of battery has its own strengths and weaknesses, and it is up to the operators of battery-requiring applications to choose the one that best meets their requirements.

Batteries have a predetermined lifespan and number of cycles depending on the climate (ambient temperature) and type of use (depth of discharge). In order to increase their lifespan and optimize their operation, it is advisable to follow the storage and use recommendations.

How do you correctly calculate the size of a battery?

In order to calculate the size of the battery you need, you will have to to calculate the expected consumption in a day and divide this sum (in watts per day) by the direct current voltage (in volts). It is not recommended to let some batteries, especially lead-acid batteries, discharge to less than 50%. To obtain the minimum power you need, divide this result (in amperes/day) by 0.5. Working in 24 V allows you to halve the power required compared to using 12 V, or even divide it by four if you work in 48 V. If you have several devices operating at the same time, it is better to have more power.

Why choose a lithium battery?

A lithium battery is an electrochemical accumulator that uses lithium as a chemical element. Any material containing lithium can be the basis of a lithium-ion battery. It is therefore very difficult to speak generally about this type of battery as high-volume markets (i.e. cameras, mobile phones, etc.) and high-energy markets (i.e. hybrid or electric vehicles, aeronautics, etc.) do not have the same needs in terms of lifespan, cost or power.

There are different types of lithium batteries:

• Lithium-ion (Li-ion): very stable batteries with a very high energy density (the highest on the market).
• Lithium polymer (Li-Po): this lithium-ion technology uses a polymer electrolyte instead of a liquid electrolyte. This electrolyte is formed by semi-solid polymers with high conductivity. This is promising dry technology.
• Lithium iron phosphate (LiFePO4): the energy density of this type of battery is lower than other technologies but it offers excellent lifespan and safety. These batteries are ideal for emergency power supplies (UPS).

Advantages:

• High energy density, which reduces the weight and volume of your batteries.
• Low maintenance.
• Rechargeable.
• Long lifespan.
• Very low self-discharge.
• Wide variety of shapes.
• Limited memory effect.

Disadvantages:

• More expensive than other types of technology.
• Require a protective circuit as they are dangerous.
• Strict regulations for transportation.
• Wear out even without use.

Cycles: provide approximately 1,300 cycles at 100% discharge.

Applications (all types of lithium batteries):

• Can store solar and wind energy.
• Can store electric energy.
• Autonomous applications (lighting of public spaces, parking meters, security cameras, radar speed signs, traffic lights, etc.).
• Mobility (electric bicycles, electric vehicles [utility ou industrial], robotics, aeronautics, drones, boats, etc.)
• Portable energy (batteries, converters, power packs).

Why choose a lead battery?

There are two types of lead batteries:

• Lead-acid batteries opened with a sulphuric acid electrolyte diluted with water. This type of battery is characterized by the fact that they are reliable and use a technology that has been well-known since the 19th century and is well mastered. These batteries have the disadvantage of being influenced by temperature changes. They also require regular maintenance (refilling with distilled water), as their electrolyte evaporates over time.
• Lead-acid batteries closed with a gel electrolyte. They have the advantage of being maintenance-free and easy to handle (no leaks) with stability that’s perfectly controlled by the manufacturer. They generally provide about 400 cycles at 80% discharge.

Advantages:

• Reliability.
• Good lifespan.
• No memory effect.
• Inexpensive.
• Low self-discharge rate, 5 to 10% per month

Disadvantages:

• Heavy.
• Low autonomy.
• Sensitive to cold.
• Require regular maintenance (only open batteries).
• Low energy density.

Applications:

• Industry.
• Equipment for rail and automotive vehicles (including trucks), airplanes, satellites, etc.

Why choose a nickel battery?

Nickel-metal hybrid batteries, known as NiMH batteries, have almost entirely replaced Ni-Cd nickel-cadmium batteries because they are less harmful for the environment. The presence of cadmium in Ni-Cd batteries poses problems for recycling batteries at the end of their life. NiMH batteries have high energy density and can be completely discharged without affecting their lifespan.

They have the disadvantage of being low capacity, which makes them more suitable for portable devices where battery life rarely exceeds a few hours. They generally provide between 500 and 700 cycles at 80% discharge.

Advantages of Ni-Cd batteries:

• Very long lifespan, up to 20 years.
• Can withstand extreme temperatures (-20°C to +40°C).
• Low internal resistance: high energy density, combined with fast charging capacity.
• Lighter than lead batteries.

Disadvantages of Ni-Cd batteries :

• More expensive.
• Pollutant: both nickel and cadmium are toxic. Battery disposal/recycling processes are expensive.
• Memory effect, the battery must be completely discharged before recharging.
• Average autonomy.

Advantages of NiMH batteries:

• Similar to Ni-Cd.
• Suffer less from memory effect.
• Better autonomy.

Disadvantages of NiMH batteries:

• More expensive.
• Subject to self-discharge.

Why choose an alkaline battery?

The most common alkaline batteries are zinc manganese dioxide (Zn-MnO2) and lithium manganese dioxide (Li-MnO2). Alkaline batteries are mainly used for domestic purposes. The main formats are cylindrical (LR3, LR6, LR14, LR20) and button cell. Due to their size and weight, alkaline batteries are widely used in low-power portable devices such as remote controls, flashlights, clocks, toys, etc.

Advantages:

• Inexpensive.
• Reasonable energy density.
• Available.

Disadvantages:

• Alkaline batteries are not normally rechargeable.

Discover what causes Li-ion to age and what the battery user can do to prolong its life.

Battery research is focusing on lithium chemistries so much that one could imagine that the battery future lies solely in lithium. There are good reasons to be optimistic as lithium-ion is, in many ways, superior to other chemistries. Applications are growing and are encroaching into markets that previously were solidly held by lead acid, such as standby and load leveling. Many satellites are also powered by Li-ion.

Lithium-ion has not yet fully matured and is still improving. Notable advancements have been made in longevity and safety while the capacity is increasing incrementally. Today, Li-ion meets the expectations of most consumer devices but applications for the EV need further development before this power source will become the accepted norm.

What Causes Lithium-ion to Age?

The lithium-ion battery works on ion movement between the positive and negative electrodes. In theory such a mechanism should work forever, but cycling, elevated temperature and aging decrease the performance over time. Manufacturers take a conservative approach and specify the life of Li-ion in most consumer products as being between 300 and 500 discharge/charge cycles.

In 2020, small wearable batteries deliver about 300 cycles whereas modern smartphones have a cycle life requirement is 800 cycles and more. The largest advancements are made in EV batteries with talk about the one-million-mile battery representing 5,000 cycles.

Evaluating battery life on counting cycles is not conclusive because a discharge may vary in depth and there are no clearly defined standards of what constitutes a cycle. In lieu of cycle count, some device manufacturers suggest battery replacement on a date stamp, but this method does not take usage into account. A battery may fail within the allotted time due to heavy use or unfavorable temperature conditions; however, most packs last considerably longer than what the stamp indicates.

The performance of a battery is measured in capacity, a leading health indicator. Internal resistance and self-discharge also play roles, but these are less significant in predicting the end of battery life with modern Li-ion.

The 1,500mAh pouch cells for mobile phones were first charged at a current of 1,500mA (1C) to 4.20V/cell and then allowed to saturate to 0.05C (75mA) as part of the full charge saturation. The batteries were then discharged at 1,500mA to 3.0V/cell, and the cycle was repeated. The expected capacity loss of Li-ion batteries was uniform over the delivered 250 cycles and the batteries performed as expected.

All packs started at a capacity of 88–94% and decreased to 73–84% after 250 full discharge cycles. The 1500mAh pouch packs are used in mobile phones.

Although a battery should deliver 100 percent capacity during the first year of service, it is common to see lower than specified capacities, and shelf life may contribute to this loss. In addition, manufacturers tend to overrate their batteries, knowing that very few users will do spot-checks and complain if low. Not having to match single cells in mobile phones and tablets, as is required in multi-cell packs, opens the floodgates for a much broader performance acceptance. Cells with lower capacities may slip through cracks without the consumer knowing. 

Similar to a mechanical device that wears out faster with heavy use, the depth of discharge (DoD) determines the cycle count of the battery. The smaller the discharge (low DoD), the longer the battery will last. If at all possible, avoid full discharges and charge the battery more often between uses. Partial discharge on Li-ion is fine. There is no memory and the battery does not need periodic full discharge cycles to prolong life. The exception may be a periodic calibration of the fuel gauge on a smart battery or intelligent device.

The following tables indicate stress related capacity losses on cobalt-based lithium-ion. The voltages of lithium iron phosphate and lithium titanate are lower and do not apply to the voltage references given.

The number of discharge/charge cycles Li-ion can deliver at various DoD levels before the battery capacity drops to 70 percent. DoD constitutes a full charge followed by a discharge to the indicated state-of-charge (SoC) level in the table.

Cycle life as a function of depth of discharge.

Depth of discharge	Discharge cycles
NMC	LiPO4
100% DoD	~300	~600
80% DoD	~400	~900
60% DoD	~600	~1,500
40% DoD	~1,000	~3,000
20% DoD	~2,000	~9,000
10% DoD	~6,000	~15,000

*  A partial discharge reduces stress and prolongs battery life, so does a partial charge. Elevated temperature and high currents also affect cycle life.

Note: 100% DoD is a full cycle; 10% is very brief. Cycling in mid-state-of-charge would have best longevity.

Lithium-ion suffers from stress when exposed to heat, so does keeping a cell at a high charge voltage. A battery dwelling above 30°C (86°F) is considered elevated temperature and for most Li-ion a voltage above 4.10V/cell is deemed as high voltage. Exposing the battery to high temperature and dwelling in a full state-of-charge for an extended time can be more stressful than cycling. Table 3 demonstrates capacity loss as a function of temperature and SoC.

Estimated recoverable capacity when storing Li-ion for one year at various temperatures.

Temperature	40% charge	100% charge
0°C	98% (after 1 year)	94% (after 1 year)
25°C	96% (after 1 year)	80% (after 1 year)
40°C	85% (after 1 year)	65% (after 1 year)
60°C	75% (after 1 year)	60% (after 3 months)

 Elevated temperature hastens permanent capacity loss. Not all Li-ion systems behave the same.

Most Li-ions charge to 4.20V/cell, and every reduction in peak charge voltage of 0.10V/cell is said to double the cycle life. For example, a lithium-ion cell charged to 4.20V/cell typically delivers 300–500 cycles. If charged to only 4.10V/cell, the life can be prolonged to 600–1,000 cycles; 4.0V/cell should deliver 1,200–2,000 and 3.90V/cell should provide 2,400–4,000 cycles.

On the negative side, a lower peak charge voltage reduces the capacity the battery stores. As a simple guideline, every 70mV reduction in charge voltage lowers the overall capacity by 10 percent. Applying the peak charge voltage on a subsequent charge will restore the full capacity.

In terms of longevity, the optimal charge voltage is 3.92V/cell. Battery experts believe that this threshold eliminates all voltage-related stresses; going lower may not gain further benefits but induce other symptoms. Table 4 summarizes the capacity as a function of charge levels. (All values are estimated; Energy Cells with higher voltage thresholds may deviate.)

Discharge cycles and capacity as a function of charge voltage limit

Charge level *(V/cell)	Discharge cycles	Available stored energy **
[4.30]	[150–250]	[110–115%]
4.25	200–350	105–110%
4.20	300–500	100%
4.15	400–700	90–95%
4.10	600–1,000	85–90%
4.05	850–1,500	80–85%
4.00	1,200–2,000	70–75%
3.90	2,400–4,000	60–65%
3.80	See note	35–40%
3.70	See note	30% and less

Every 0.10V drop below 4.20V/cell doubles the cycle but holds less capacity. Raising the voltage above 4.20V/cell would shorten the life. The readings reflect regular Li-ion charging to 4.20V/cell.

Guideline: Every 70mV drop in charge voltage lowers the usable capacity by about 10%.

Note: Partial charging negates the benefit of Li-ion in terms of high specific energy.

* Similar life cycles apply for batteries with different voltage levels on full charge.

** Based on a new battery with 100% capacity when charged to the full voltage.

Most chargers for mobile phones, laptops, tablets and digital cameras charge Li-ion to 4.20V/cell. This allows maximum capacity, because the consumer wants nothing less than optimal runtime. Industry, on the other hand, is more concerned about longevity and may choose lower voltage thresholds. Satellites and electric vehicles are such examples.

For safety reasons, many lithium-ions cannot exceed 4.20V/cell. (Some NMC are the exception.) While a higher voltage boosts capacity, exceeding the voltage shortens service life and compromises safety. Figure 5 demonstrates cycle count as a function of charge voltage. At 4.35V, the cycle count of a regular Li-ion is cut in half.

Effects on cycle life at elevated charge voltages. Higher charge voltages boost capacity but lowers cycle life and compromises safety.

Besides selecting the best-suited voltage thresholds for a given application, a regular Li-ion should not remain at the high-voltage ceiling of 4.20V/cell for an extended time. The Li-ion charger turns off the charge current and the battery voltage reverts to a more natural level. This is like relaxing the muscles after a strenuous exercise.

Figure 6 illustrates dynamic stress tests (DST) reflecting capacity loss when cycling Li-ion at various charge and discharge bandwidths. The largest capacity loss occurs when discharging a fully charged Li-ion to 25 percent SoC (black); the loss would be higher if fully discharged. Cycling between 85 and 25 percent (green) provides a longer service life than charging to 100 percent and discharging to 50 percent (dark blue). The smallest capacity loss is attained by charging Li-ion to 75 percent and discharging to 65 percent. This, however, does not fully utilize the battery. High voltages and exposure to elevated temperature is said to degrade the battery quicker than cycling under normal condition.

Capacity loss as a function of charge and discharge bandwidth.*

Charging and discharging Li-ion only partially prolongs battery life but reduces utilization.

Case 1: 75–65% SoC offers longest cycle life but delivers only 90,000 energy units (EU). Utilizes 10% of battery.

Case 2: 75–25% SoC has 3,000 cycles (to 90% capacity) and delivers 150,000 EU. Utilizes 50% of battery. (EV battery, new.)

Case 3: 85–25% SoC has 2,000 cycles. Delivers 120,000 EU. Uses 60% of battery.  

Case 4: 100–25% SoC; long runtime with 75% use of battery. Has short life. (Mobile phone, drone, etc.)

Only a full cycle provides the specified energy of a battery. With a modern Energy Cell, this is about 250Wh/kg, but the cycle life will be compromised. All being linear, the life-prolonging mid-range of 85-25 percent reduces the energy to 60 percent and this equates to moderating the specific energy density from 250Wh/kg to 150Wh/kg. Mobile phones are consumer goods that utilize the full energy of a battery. Industrial devices, such as the EV, typically limit the charge to 85% and discharge to 25%, or 60 percent energy usability, to prolong battery life.

Increasing the cycle depth also raises the internal resistance of the Li-ion cell. Figure 7 illustrates a sharp rise at a cycle depth of 61 percent measured with the DC resistance method. The resistance increase is permanent.

Sharp rise in internal resistance by increasing cycle depth of Li-ion.

Extrapolates the data to expand the predicted cycle life of Li-ion by using an extrapolation program that assumes linear decay of battery capacity with progressive cycling. If this were true, then a Li-ion battery cycled within 75%–25% SoC (blue) would fade to 74% capacity after 14,000 cycles. If this battery were charged to 85% with same depth-of-discharge (green), the capacity would drop to 64% at 14,000 cycles, and with a 100% charge with same DoD (black), the capacity would drop to 48%. For unknown reasons, real-life expectancy tends to be lower than in simulated modeling.

Predictive modeling of battery life by extrapolation.

Li-ion batteries are charged to three different SoC levels and the cycle life modelled. Limiting the charge range prolongs battery life but decreases energy delivered. This reflects in increased weight and higher initial cost.

Battery manufacturers often specify the cycle life of a battery with an 80 DoD. This is practical because batteries should retain some reserve before charge under normal use. The cycle count on DST (dynamic stress test) differs with battery type, charge time, loading protocol and operating temperature. Lab tests often get numbers that are not attainable in the field. 

What Can the User Do?

Environmental conditions, not cycling alone, govern the longevity of lithium-ion batteries. The worst situation is keeping a fully charged battery at elevated temperatures. Battery packs do not die suddenly, but the runtime gradually shortens as the capacity fades.

Lower charge voltages prolong battery life and electric vehicles and satellites take advantage of this. Similar provisions could also be made for consumer devices, but these are seldom offered; planned obsolescence takes care of this.

A laptop battery could be prolonged by lowering the charge voltage when connected to the AC grid. To make this feature user-friendly, a device should feature a “Long Life” mode that keeps the battery at 4.05V/cell and offers a SoC of about 80 percent. One hour before traveling, the user requests the “Full Capacity” mode to bring the charge to 4.20V/cell.

The question is asked, “Should I disconnect my laptop from the power grid when not in use?” Under normal circumstances this should not be necessary because charging stops when the Li-ion battery is full. A topping charge is only applied when the battery voltage drops to a certain level. Most users do not remove the AC power, and this practice is safe.

Modern laptops run cooler than older models and reported fires are fewer. Always keep the airflow unobstructed when running electric devices with air-cooling on a bed or pillow. A cool laptop extends battery life and safeguards the internal components. Energy Cells, which most consumer products have, should be charged at 1C or less. Avoid so-called ultra-fast chargers that claim to fully charge Li-ion in less than one hour.

It is customary to preset a battery factory laptop computer for you how many times they may need to be recharged. Whenever the laptop is loaded, it continues to drain parts of his record capacity. It is recommended to have exceeded win a laptop battery in the middle of his term of additional cargo.

Follow the instructions below to have an efficient laptop battery recycling.

1. From the laptop, power, and let it run solely on battery power. Use the laptop and the battery completely until the phone turns itself off
2. Leave your laptop must be turned off within 10 to 15 minutes, and not feeding at this time.
3. Turn on the computer and use the power button. Do not try to connect to the network yet. Leave the laptop turn off by itself again and make sure the laptop’s battery is completely discharged.
4. With the battery still attached to the laptop is the laptop to the electricity grid. Fully charge the battery is displayed on the screen. Then download it again for another 30 minutes.
5. By repeating the process several times, or perhaps to the days when the restoration of the laptop battery is fully realized.
6. It is advisable to download a software for monitoring application of laptop batteries for the charging and discharging to monitor the laptop battery. There is always the pursuit of the overall performance of laptop battery.

Further information and warnings:

• It is advisable to proceed with the battery in the revision of night. This is to make the process continuously or without interruptions.
• If restoration of the battery is reached, the battery is completely discharged each time before charging again. The working process in place must be repeated every 2-4 months.
• Keep the battery in a cool, dry place when not in use. Major notebook manufacturers are advised to discourage the battery to cool to about sixty degrees Fahrenheit to maintain the discharge prematurely.
• Do not try the laptop battery in the refrigerator or freezer. This could damage the battery is strong.
• Do not drop the laptop battery.
• Replace the battery to extreme temperatures.
• Do not leave the laptop outside in cold weather.
• Leave the laptop in a car that is parked on a hot day. The increase in temperature can lead to premature rejection of the batteries.
• Always use the power of electricity to keep the battery charged.
• Do not use the laptop for a long period.
• In some cases, laptop equipped with two batteries to operate. If it is not possible, ask the manufacturer of the laptop to the availability of high-capacity battery. An external battery can be used over a long period of laptop use.

The management of laptop batteries is useful, and is in excellent condition ready for use each time.

Most people buy laptops because they should be portable. To move around the house or working in cafes or the library. Unfortunately, it is not always as much as you want because you can not always find a place to plug fitted luck, laptops are equipped with batteries.

It is not as good as it sounds good. The laptop battery standard (in a 14 or 15 inch laptop) is a 6-cell battery that lasts about 2 hours. You can take a little longer than that, or something less. It depends on what you do. When you press the phone (playing DVDs or editing photos), the battery quickly. Just think how tired you feel when you faster if you run on foot.

Fortunately, you are not set with just 2 hours. You have some options.

First, you can always buy a second battery. Then when you run just before the juice, just swap batteries. This will give you four hours.

Better yet, buy a second battery that is more capacity(9cell,12cell) for your original battery. As I said, most laptop batteries with 6-cell battery. You can use the batteries that will give you more battery life longer. You can extend battery manufacturer’s computer, be it Apple, Dell, HP, Sony, or anyone else. They are more expensive, but they are a good way to work more if you’re out to get.

What are your main options, but there are ways of their owners. For example, Dell sells what is called a modular battery. Instead of dragging your optical drive (DVD or CD) and inserting the battery. Then you get the battery life, because your laptop has two batteries. The device uses the modular battery first only if you want to use in your optical drive. This way you get the maximum battery life, since the main battery is not used, will be used until the battery module.

This just proves that every manufacturer improve in this area all the time trying. So always check what your manufacturer has available to improve your battery life. People keep talking about a revolution in this area, but for now, have to be creative to get the most out of your laptop.

They are very busy working on the laptop and there’s no outlet nearby. They work on the battery and the battery indicator “Battery low” or “low battery -. Please turn off the computer or it will go to sleep” Is it common? How many times have you in this situation where you do not have any choice, take your laptop because the battery is low? or how many times have you given the situation where your laptop itself off because of low battery? How long do you have with your laptop battery? It may just have time for you to get his new laptop battery.

If you already have your laptop for a very long time and have not yet changed the batteries once, and if your backup time is reduced considerably, it is time to buy new laptop batteries. Laptop batteries only last for about 4 years. Books quickly lose their charm if they do not have good battery backup, your laptop may seem a UPS computer, if so. New Laptop Batteries must be paid in any event the price.

batteries for laptops are available in different specifications. There are 12 batteries that offer very good battery life on, and there’s 9-cell battery, 8 cell battery, 6-cell battery, 4 cell battery and 3 cell batteries. In addition, the designs differ from the battery manufacturer. Each manufacturer has a different type of battery and are therefore portable battery manufacturer specific. For example, you can not use a Dell laptop battery with HP laptop, or vice versa.

If you do not intend to buy a battery and prolong the life of your batteries, there are some things you could do. Although a new laptop battery would be a better option, you can always old, until they die completely. Some helpful tips are: defragment your hard drives regularly, do not ever bright screen – dim the screen when you can reduce the number of programs running in the background that this work be used in processor and greater exchange laptop batteries run your programs and videos from your hard drive instead of CD players, add more RAM to the laptop, if possible. These are just some suggestions to help you are able to continue until you go to buy your new laptop battery.

Smartphone users — casual and enthusiast alike — are forever in search of longer battery life. While fast charging keeps us topped up every day, the absence of replaceable batteries means eventually the lithium-ion cells enclosed in our phones are going to age and deteriorate.

If you’ve held onto a phone for a year or more, you’ve probably noticed the battery doesn’t seem to last as long as it did when it was brand new. Two years down the line and many phones struggle to make it through the day on a single charge. Holding onto a phone past three years can even spell trouble for system stability.

Unfortunately, battery capacity inevitably declines with age. However, there are things you can do to prolong the life of your battery and handset. If you’ve ever wondered what the best way to charge your battery is, here are some scientifically proven tips for maximizing battery life.

Partial charging is the way to go

One particularly persistent battery myth is that you need to occasionally fully discharge and recharge to erase “battery memory.” This couldn’t be more wrong for lithium-ion batteries. It’s a leftover myth from lead-acid cells and it’s actually quite undesirable to charge your modern smartphone in this way.

Partial charging is just fine for lithium-ion batteries and can actually have some positive benefits for cell longevity. To understand why it’s important to appreciate how a battery charges. When closer to empty, Li-ion batteries draw constant current and operate at a lower voltage. This voltage gradually increases as the cell charges up, leveling off at around a 70 percent charge before the current begins to fall until the capacity is full.

Importantly, operating at a low voltage is good for a battery’s lifespan, increasing the number of available charging cycles before you’ll start to see a major reduction in capacity. Roughly speaking, every 0.1V decrease in cell voltage doubles the cycle life, according to Battery University. Therefore, charging up your phone in that 30 to 80 percent range keeps the voltage lower and prolongs the battery lifespan.

Furthermore, the “depth-of-discharge” has a similar effect on the total discharge cycles before battery capacity drops off. This refers to the amount the battery used up in between charges. Smaller discharges, in the region of 60 percent rather than 100 percent between refueling can double the lifespan of your battery, and only using 20 percent can double the life again.

Using up just 20 percent of your battery between charges isn’t going to be practical for most people, but topping up when you’ve used about half will see a notable improvement in your battery life over the long term, especially if you avoid charging up to full each time too. The bottom line is that small regular top-ups are much better for Li-ion batteries than long full charge cycles.

Avoid idle charging

Charging overnight or in a cradle during the day is a very common habit, but it’s not recommended for several reasons (the old “overcharging” myth isn’t one of them). First, continuous trickle charging of a full battery can cause plating of the metallic lithium, which reduces stability in the long term and can lead to system-wide malfunctions and reboots. Secondly, it leaves the battery at the higher stress voltage when at 100 percent, as we just mentioned above. Third, it creates excess heat caused by wasted power dissipation.

Ideally, a device should stop charging when it reaches 100 percent battery capacity, only turning the charging circuit back on to top up the battery every now and again — or at the very least reducing the charging current to very small amounts.

I tested a few phones charged to 100 percent and they continued to pull up to half an amp and sometimes more from the wall outlet. Turning the smartphones off doesn’t make a difference in many cases, with only the LG V30 dropping down to below 20mA when off and still plugged in. Most phones hover between 200 and 500 mA.

A final point worth mentioning is parasitic load. This occurs when the battery is being drained significantly at the same time as being charged, such as watching a video or gaming while charging.

Parasitic loads are bad for batteries because they distort the charging cycle and can induce mini-cycles, where part of the battery continually cycles and deteriorates at a faster rate than the rest of the cell. Worse still, parasitic loads occurring when a device is fully charged also induce higher voltage stress and heat on the battery.

The best way to avoid parasitic loads it to turn your device off while charging. But it’s probably more realistic to keep the workload very light while the device is plugged in, leaving it to idle most of the time. Remember to unplug it once the battery is topped up enough.

Heat is the enemy of long battery life

Along with all of the above, temperature is an equally key contributor to battery longevity. Just like high voltages, high temperatures stress the battery and make it lose capacity far more quickly than when kept at lower temperatures.

A cell kept between 25 – 30 degrees Celsius (77 – 86 degrees Fahrenheit) should retain around 80 percent of its capacity after the first year even when cycling from empty to full charge. Battery capacity will be higher than this after a year if smaller periodic charging cycles are used. Raising the temperature to 40C (104F) sees this fall to just 65 percent capacity after the first year, and a 60C (140F) battery temperature will hit this marker in as little as three months.

A battery dwelling in a full state-of-charge exposed to a high temperature is the worst of all worlds and the number one thing to avoid when charging your phone. So no leaving your phone under your pillow to charge at night or plugged in on the dashboard of your car on a hot day.

Fast charging technologies are a contentious issue here, as the higher current and voltages can definitely lead to a hotter device while charging. Fast charging was never really envisioned for full-cycle charging though, instead, it’s a fast way to top up your phone quickly to get it back in your hands. Leaving your phone to quickly charge up for 15 to 20 minutes won’t lead to major overheating problems, but I certainly don’t recommend using them for overnight charging.

Bringing this all together

Lithium-ion battery technology is well understood these days, but bad habits and myths still permeate public consciousness. While most of these habits won’t severely negatively impact your phone’s battery life in the medium term, the decline in removable phone batteries means we should take extra precautions to maximize our phone’s battery life and cell longevity.

Broadly speaking, smaller regular charge cycles and keeping your phone cool are the key things to remember. Although I should point out that different phone batteries will always age slightly differently depending on how we treat them. Here’s a TL;DR summary of the battery tips above:

What’s the best way to charge your smartphone?

• Avoid full cycle (zero-100 percent) and overnight charging. Instead, top-up your phone more regularly with partial charges.
• Ending a charge at 80 percent is better for the battery than topping all the way up to 100 percent.
• Use fast charging technologies sparingly and never overnight.
• Heat is the battery killer. Don’t cover your phone when charging and keep it out of hot places.
• Turn your phone off when charging, or at least don’t play games or watch videos to avoid mini-cycles.