
Arirang (Korean: 아리랑) is a line of North Korean Android smartphones. They were announced on 10 August 2013. The phone was distributed to local sales points operated by mobile operators such as Koryolink to be sold together with 3G SIM cards or as a stand-alone device. It is named after the "Arirang" Korean. . In 2013, toured a factory called the "May 11 Factory" that makes the "Arirang" . In the August of same year, first Arirang was released and was claimed to the first domestically produced smartphone. . • • • [pdf]
North Korea's government only allows its citizens to use smartphones it created to monitor and control them. While we can't get hold of them here, there's plenty of information available that gives us a fascinating look into the world of North Korean smartphones. Smartphones were introduced to North Korea in 2002, then banned from 2004 to 2008.
The new report catalogs 55 smartphones that have been sold in North Korea, with specifications and other information where available. View and download a copy of the full report at Lumen. In this new report, Martyn Williams examines smartphones, the smartphone market, and wireless networks in North Korea.
One trend noted in recent years is that North Korean smartphone brands appear to have begun offering several versions of a phone with differing specifications. This mirrors the strategy of companies like Apple and Samsung with their flagship products.
These smartphones from North Korea are more than just messaging devices; they act as systems for oversight. Two built-in applications called ‘Red Flag’ and ‘Trace Viewer’ guarantee that the state monitors all device activities. The program Red Flag observes the phone software to stop any illicit changes from happening.
Recent reports say digital payment apps have also been enthusiastically adopted despite their potential for additional surveillance of citizens. One trend noted in recent years is that North Korean smartphone brands appear to have begun offering several versions of a phone with differing specifications.
A glimpse of a North Korean phone with a built-in mosquito repellant. There's also a Google Drive icon that opens a screensaver app. It's hard to confirm these phones' details reliably. Some specifications here are sourced directly from the DPRK state media, so take those with a bucketload of salt.

A sodium–sulfur (NaS) battery is a type of that uses liquid and liquid . This type of battery has a similar to , and is fabricated from inexpensive and low-toxicity materials. Due to the high operating temperature required (usually between 300 and 350 °C), as well as the highly reactive nature of sodium and The advantages are that the cells have a higher voltage, wider operating temperature range, are less corrosive and have safer reaction products. [pdf]
Energy density: The high energy density (110 Wh/kg) and power density (150 W/kg) of sodium sulfur batteries make them ideal for use in various applications. Low-cost materials: As sodium salt is one of the most abundant elements on Earth, sodium sulfur batteries cost less than other batteries, such as lithium-ion batteries.
Safety: As the sodium sulfur batteries operate at very high temperatures, the safety risk makes them less suitable for BTM applications. Moreover, the sodium battery is highly dangerous if the liquid sodium comes into contact with water in the atmosphere. 6. Applications of Sodium Sulfur Batteries
Lifetime is claimed to be 15 year or 4500 cycles and the efficiency is around 85%. Sodium sulfur batteries have one of the fastest response times, with a startup speed of 1 ms. The sodium sulfur battery has a high energy density and long cycle life. There are programmes underway to develop lower temperature sodium sulfur batteries.
Sodium sulfur batteries are increasingly being used to stabilize output from wind and solar power generators. Furthermore, NaS batteries present significant opportunities to generate clean energy at a low cost and transition to a decarbonized economy using plentiful resources like sodium, which can be processed from seawater.
The following are the main disadvantages of sodium sulfur batteries: Operational cost: The increased operational cost of sodium sulfur batteries is due to the high temperature (350°C) required to liquefy sodium. Production capacity: Unlike Li-ion batteries, sodium sulfur batteries are not yet established in the market.
The sodium–sulfur battery uses sulfur combined with sodium to reversibly charge and discharge, using sodium ions layered in aluminum oxide within the battery's core. The battery shows potential to store lots of energy in small space.

How to maximize Lead Acid Battery Capacity1. Proper Charging Techniques Charging is a critical factor in maximizing lead acid battery capacity. The charging process needs to be carefully managed to avoid issues such as undercharging or overcharging. . 2. Equalization Charging . 3. Temperature Control . 4. Avoiding Deep Discharges . 5. Battery Sulfation Prevention . 6. Regular Maintenance and Inspection . [pdf]
To prolong the lifespan of your battery, you need to know how it works. As you already know, Lead Acid Batteries are rechargeable. They use Lead and Sulphuric acid to function. The lead is dipped into the Sulphuric acid to allow a chemical reaction. The chemical reaction causes the battery to generate an electric charge.
Proper use is essential to maximize the life of lead-acid batteries. Here are some recommendations: Avoid frequent deep discharges: Deep discharges can significantly reduce battery life. A deep discharge is generally defined as a discharge below 50% of the battery’s total capacity.
If at all possible, operate at moderate temperature and avoid deep discharges; charge as often as you can (See BU-403: Charging Lead Acid) The primary reason for the relatively short cycle life of a lead acid battery is depletion of the active material.
Each piece of equipment has to perform together seamlessly, so customers enjoy uninterrupted power and their investment is maximized. Batteries can be one of the more costly products to purchase upfront and to replace over time. This article explains best practices to care for lead acid batteries to avoid downtime and extend battery life.
As you already know, Lead Acid Batteries are rechargeable. They use Lead and Sulphuric acid to function. The lead is dipped into the Sulphuric acid to allow a chemical reaction. The chemical reaction causes the battery to generate an electric charge. The same reaction is reversed to recharge the battery.
Storage location and conditions of a battery can adversely affect a battery’s durability and performance. To let the lead acid battery perform at its peak capability, it must be stored in a cool, dry place with an ideal temperature. You should also avoid storing batteries in areas where there is direct sunlight or extreme freeze.
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