To learn more about the development process behind the new flagship line’s powerhouse battery, Samsung Newsroom sat down with developers who helped bring the battery to life – Hyeonsu Lee, Hongjung Son, Yusu Kim and Juhyang Lee – as well as Product Planner Jeongmin Moon.

(Clockwise from left) Yusu Kim, Hyeonsu Lee, Hongjung Son, Juhyang Lee, and Jeongmin Moon

Changing Charging for the Better

According to Product Planner Jeongmin Moon, the development team incorporated Wireless PowerShare technology into the Galaxy S10 line to offer users the freedom to go about their day without being tied down by cables and chargers.

“We wanted to solve the inconvenience of having to carry around multiple chargers and cables when you’re out and about, or having to interrupt your day to stop at places like cafes just to charge your phone,” said Moon. “So we came up with the idea to essentially make the Galaxy S10 a wireless charger in and of itself.”

Since the release of the Galaxy S6, the first Galaxy device to offer wireless charging, more and more smartphones and wearables have begun to feature the technology as well. This, Yusu Kim noted, is another reason why Samsung prioritized incorporating wireless battery-sharing technology into the Galaxy S10 line.

“Wireless PowerShare allows you to easily share your battery’s power anytime, anywhere,” said Kim. “And as more devices begin to support wireless charging, more people will be able to experience the convenience that the technology creates.”

The technology behind wireless battery sharing and wireless charging is quite similar. A wireless charger receives DC (direct current) charge and converts it to AC (alternating current) with the battery coil before transmitting it to the receiving smartphone. The phone will then convert the AC charge back to DC and save the energy in the battery. Each Galaxy S10 device features a circuit that enables this two-way conversion, which essentially allows the phones serve as wireless chargers as well.

As mentioned above, the list of Wireless PowerShare-compatible devices includes not only smartphones, but, in an industry first, wearables1 like Samsung’s Galaxy Watch and Galaxy Buds as well. As Juhyang Lee explained, the process of enabling the technology to work with such a wide range of devices was quite a difficult task.

“The sizes of these devices’ batteries are all different, so the most difficult part of the process was finding an optimal spot for the receiving coils that would result in maximum efficiency,” Lee explained. With the smartwatch, she recalled “the receiving coil was particularly small, so it took some time to find the most efficient approach. However, after months and months of extensive research, we produced a solution that meets our strict reliability standards.”

A Smarter Approach to Battery Management

Of course, in order to share its charge with another device, your Galaxy S10’s battery must possess enough power to efficiently operate your phone. (At least 30 percent, to be precise.) To offer users more freedom to utilize this useful function, the Galaxy S10 line features AI technology that optimizes battery usage based on how you use your phone.

(From left) Hongjung Son and Hyeonsu Lee

When building this technology, the developers focused particularly on the battery consumption of infrequently used apps. As Hongjung Son explained, “Out of all the apps that users have on their phones, only a small number are used every day. And the ones that aren’t used consume battery power in the background.”

“To limit these apps’ background activities,” he continued, “we incorporated AI technology that organizes apps into different categories, such as ‘frequently used,’ ‘occasionally used,’ and ‘rarely used.’”

The team also enabled the new smartphones’ Adaptive Power Saving mode to activate automatically² based on users’ usage patterns. Hyeonsu Lee described how it works: “If, for example, a user usually uses their phone for 30 minutes on their way to work, Adaptive Power Saving mode will automatically activate if their commute happens to get extended.”

“And because this mode is AI-powered,” he added, “the more it’s used, the more accurate it becomes.”

The efficiency of the Galaxy S10’s battery has been amplified with stronger hardware. At 7.8mm thick, it’s thinner than the Galaxy S9’s 8.5mm battery, and its capacity has been increased by 10 percent (from 3000-3500mAh to 3400-4100mAh)3.

A Powerful Vision

Each member of the product planning and development teams agrees that Samsung’s latest battery innovations will unlock unprecedented user experiences.

Moon concluded the interview by shedding some light on the company’s ultimate goals for its charging technology. “With Wireless PowerShare, we not only expect to resolve some of the inconvenient aspects of charging your devices,” said Moon. “We also expect people to communicate and engage with one another more.”

“Listening carefully to users’ feedback has enabled us to consistently improve our Galaxy smartphones,” added Kim, “and it will continue to do so. Going forward, we’ll continue to strive to develop battery technology that offers the very best in terms of users’ convenience and experience.”

¹ Using Wireless PowerShare, you can charge Samsung and Qi-certified phones, and wearables such as Galaxy S9, S9+, S8, S8+, S8 Active, S7, S7 edge, S7 Active, S6, S6 edge, S6 Active, S6 edge+, Note9, Note8, Note FE, Note5, and wearables such as Galaxy Watch Active, Gear Sport, Gear S3, Galaxy Watch (46/42mm), and Galaxy Buds. It may not work with certain accessories, covers, or other brand devices. Wireless PowerShare may also affect call reception or data services, depending on your network environment.

² Users may specify whether or not they’d like Adaptive Power Saving mode to automatically activate in their Galaxy S10’s settings.

³ Typical value tested under third-party laboratory condition. Typical value is the estimated average value considering the deviation in battery capacity among the battery samples tested under IEC 61960 standard. Rated (minimum) capacity is 3000mAh for Galaxy S10e, 3300mAh for Galaxy S10 and 4000mAh for Galaxy S10+. Actual battery life may vary depending on network environment, usage patterns and other factors.

Youngho Seo and Seonyoung Park of the Mechanical R&D, and SeungChul Choi and Chulwoo Park of the Advanced Component Technology, explained what elements went into creating an optimized battery environment and experience for the Galaxy S7 and S7 edge, and the challenges of working to balance the three most important elements of the battery usage triangle – efficient and larger battery size, extended running time, and faster and safer charging.

(From left to right) Chulwoo Park, SeungChul Choi, Seonyoung Park and Youngho Seo

Q. What are some of the challenges of developing smartphone batteries?

Youngho Seo: Customers often feel that their battery on their smartphone is not enough — they want it to last longer. Although it should be possible to increase battery capacity to meet the user’s expectations, there are technical difficulties at play that make it difficult to do so. Finding ways to overcome these obstacles is the toughest challenge in battery development.

Seonyoung Park: Another challenge in battery development is the long trial period. Smartphone batteries have to be tested for many years in order to prove they deliver the same performance, even after hundreds of recharges. This obviously takes a long time.

Q. What did you focus on the most in working to improve the battery of the Galaxy S7 and S7 edge?

Youngho Seo: A key focus was to improve the battery’s energy density, which is the amount of energy stored in a specific size of a physical space. We were determined to design a battery with increased capacity—but without adding any bulk—in order to preserve the Galaxy S7’s compact design. As a result, higher energy density was applied to the Galaxy S7 and S7 edge, equipping both phones with battery capacities of 3,000mAh and 3,600mAh respectively.

Q. What other steps were taken to increase the battery running time of the Galaxy S7 and S7 edge?

Seungchul Choi: In order to extend battery life, it is crucial to have both a larger power storage capacity and minimal electricity consumption rate-per-hour. Power consumption will increase unless battery usage is optimized by adding components like the smartphone chipset design to its application. To extend the Galaxy S7’s battery life, we worked across the many departments that led the development of the Galaxy S7 at every stage — from planning to verification. When too much energy was used while developing new features, we conducted thorough reviews and worked together on solutions to provide the same function while consuming less energy.

In addition, various options were introduced to the new phone to reduce energy consumption, such as the App power saving feature, which is a function that lets users set a specific time during which the application is inactive and can save power within the Smart Manager.

Q. Have you made any improvements to the battery to reduce the charging time?

Chulwoo Park: Samsung has provided a fast-charging feature since 2014 when we launched the Galaxy Note4. When the Galaxy S6 launched last year, we added algorithms to enhance stability during fast charging. In the Galaxy S7 and S7 edge, the usability has been improved even further with the addition of a new algorithm for longer battery life.

The fast charging technology needs to not only save time – but do it safely. We do this by ensuring that there is no excess electricity inflow through the product other than the amount required for charging. This is possible through bilateral communication, which monitors the power charging levels between the device and charger. In addition, safety features inside the charger protect the smartphone and battery against possible issues such as dirt, or water interference.

Specifically, the Galaxy S7 and S7 edge have a seven-step safety feature that is applied to the charger and battery to enhance consumer protection.

Q. Since the Galaxy S7 and S7 edge are water and dust resistant, would it be safe to charge them when they’re wet?

Chulwoo Park: For safety purposes, the Galaxy S7 and S7 edge have an ID pin in the USB port that will detect that the device is connected to the charger. If a foreign substance like water is sensed by the ID pin, the charger will not work. It is recommended that phones are kept free from moisture and any other foreign substance before charging.