Specifications Weight (g) 750 Depth (mm) 500 Width (mm) 140 Height (mm) 190 Input/Output Other Battery Capacity (mAh) 8000 Sound Mode Other Category Speakers Use HOME Input Power (W) <25 W Voice Control No Waterproof No Support APP No Playback Function MP3 Remote Control No Intelligent Personal Assistant None Display Screen Yes Built-in Microphone No Audio Crossover Two-Way Number of Loudspeaker Enclosure 1 Power Source Battery Channels 2 (2.0) Feature Wireless Charger for Mobile Phone Battery Yes Communication Bluetooth Speaker Type Portable Cabinet Material Plastic Brand Name RNABAU Model DB Origin Mainland China Certification CE Type1 Caixa De Som Type2 HiFi Wireless Bluetooth Speaker Type3 Mobile Phone Charger Type4 Alarm Clock Speaker Type5 FM Radio Soundbox Type6 Vintage Bluetooth Speaker Type7 Home Stereo Audio Set
BenQ RE03A 86 inch Board Essential RE8603A is designed for classrooms, training rooms, and interactive presentations. It features an 86-inch 4K UHD IPS display with precision IR touch technology for smooth writing and collaboration. Additionally, it supports up to 40 touch points. Therefore, it helps teachers and teams work together more efficiently. The BenQ RE8603A delivers 3840 × 2160 resolution with 450 nits brightness and anti-glare coating for clear viewing in bright rooms. Moreover, it uses 9H tempered glass for better durability and safer daily use. It also includes low blue light and flicker-free technology to reduce eye strain. In addition, it runs on Android 11 with 4GB memory and 32GB storage for smooth system performance. Furthermore, it provides 3 HDMI 2.0 ports, DisplayPort, USB-A, USB-C, and USB-B for flexible connectivity. As a result, users can connect laptops, cameras, and classroom devices easily. It also includes front-facing 2 × 20W speakers and built-in management tools for daily educational use. Specifications: 86-inch 4K UHD (3840 × 2160) IPS display Precision IR touch with up to 40 touch points Android 11 with 4GB RAM and 32GB storage 450 nits brightness with anti-glare 9H tempered glass 3 HDMI 2.0, DisplayPort, USB-C, and dual 20W speakers
The MSI MAG 276CXF 27″ 280Hz Curved Gaming Monitor delivers an immersive gaming experience. With a fast 280Hz refresh rate, it ensures ultra-smooth gameplay. Say goodbye to motion blur and enjoy crystal-clear visuals. This monitor features a 1500R curved design that enhances immersion. It wraps around your field of vision, making gaming more engaging. Whether you’re playing fast-paced shooters or open-world adventures, the curved screen provides an edge. The MSI MAG 276CXF has a Full HD resolution for sharp and vibrant images. It supports a wide color gamut, offering lifelike colors and rich contrast. Enjoy every detail in your favorite games and multimedia content. With a lightning-fast 1ms response time, ghosting and lag are minimized. This ensures smooth transitions and precise actions, giving you a competitive advantage. The monitor is also compatible with AMD FreeSync Premium, which eliminates screen tearing and stuttering. Connectivity is easy with multiple ports, including HDMI and DisplayPort. You can easily connect your PC, gaming console, or other devices. The MSI MAG 276CXF 27″ 280Hz Curved Gaming Monitor is designed for long gaming sessions. It includes eye-care technology, reducing blue light and flicker to minimize eye strain. Play longer without discomfort. With a stylish and modern design, this monitor enhances any gaming setup. Its slim bezels offer an immersive multi-monitor experience. Whether you’re a casual gamer or an esports enthusiast, this monitor delivers outstanding performance. Upgrade your gaming with the MSI MAG 276CXF 27″ 280Hz Curved Gaming Monitor today. Specifications: Display : 27″ Rapid VA Resolution : 1920×1080 (FHD) Curvature : 1500R Refresh Rate : 280Hz Response Rate :0.5ms
Samsung Monitor 27″ FHD monitor with IPS panel Screen Size (Class)27 Active Display Size (HxV) (mm)596.736 x 335.664 Aspect Ratio16:9 Panel TypeIPS Brightness (Typical)400 cd/㎡ Brightness (Min)320 cd/㎡ Contrast Ratio Static1,000:1(Typ.) Dynamic Contrast RatioMega ∞ DCR HDR(High Dynamic Range)HDR10 Resolution1,920 x 1,080 Response Time1ms (GTG) Viewing Angle (H/V)178°/178° Color SupportedMax 16.7M sRGB Coverage99% Refresh RateMax 240Hz General Feature Eco Saving PlusYes Eco Light SensorYes Eye Saver ModeYes Flicker FreeYes Windows CertificationWindows 10 FreeSyncFreeSync Premium G-SyncG-Sync Compatible Off Timer PlusYes Black EqualizerYes Low Input Lag ModeYes Virtual AIM PointYes Refresh Rate OptimizorYes Specifications: Samsung Monitor 27″ FHD monitor with IPS panel Screen Size (Class)27 Flat / CurvedFlat Active Display Size (HxV) (mm)596.736 x 335.664 Aspect Ratio16:9 Panel TypeIPS Brightness (Typical)400 cd/㎡ 3-Year Warranty
Brand-new UK-layout keyboard replacement (Z1 Black) for MacBook Air models with M2, M3, and M4 chips (13.6″ and 15″, 2023–2025). Compatible with A2681 and A2941—precision-engineered for seamless fit and reliable typing performance. This is a brand-new, high-quality keyboard replacement designed specifically for the latest MacBook Air models featuring Apple’s M2, M3, and M4 chips (released 2023–2025). It fits both the 13.6-inch (Model A2681) and 15-inch (Model A2941) MacBook Air variants and comes in the sleek Z1 Black (Space Black) finish with a UK English layout (including the £ symbol and correct key positioning). Engineered to match Apple’s original specifications, this keyboard ensures a responsive, quiet, and comfortable typing experience with consistent key travel and tactile feedback. It includes the full top case assembly with integrated backlighting, function keys, and Touch ID sensor cutout (sensor not included), making it ideal for professional repairs or replacements after liquid damage, wear, or key failure. Installation requires technical expertise and proper tools due to the integrated nature of the MacBook Air’s top case design. Recommended for certified technicians or experienced repair professionals. Important Notes: This is a keyboard + top case assembly, not just keycaps. Touch ID sensor is not included—you must transfer your original sensor to maintain functionality. Compatible only with MacBook Air M2 (2022–2023), M3 (2023–2024), and M4 (2024–2025) models in 13.6″ (A2681) and 15″ (A2941) sizes. Color: Z1 Black (Space Black) – matches official Apple Space Black finish. Layout: UK English (ISO) – features the correct “£” key and shifted Enter key.
The LG UltraGear 27″ 180Hz Curved Monitor is built for gamers who demand smooth visuals and immersive experiences. Its 27-inch curved screen pulls you into the action with an engaging field of view. With a 180Hz refresh rate, this monitor delivers ultra-smooth motion, reducing blur during fast-paced gameplay. The LG UltraGear 27″ 180Hz Curved Monitor also supports high resolution for sharp details and vibrant visuals. Its curved design enhances immersion, making games, movies, and work tasks more enjoyable. The IPS panel ensures accurate colors and wide viewing angles for consistent quality. Additionally, the LG UltraGear 27″ 180Hz Curved Monitor includes AMD FreeSync and NVIDIA G-SYNC compatibility. This reduces tearing and stuttering, ensuring smoother gaming performance. Its low response time allows quick reactions, giving competitive players a clear advantage. With HDR support, the monitor delivers better brightness and contrast for lifelike imagery. The LG UltraGear 27″ 180Hz Curved Monitor also provides multiple connectivity options, including HDMI and DisplayPort. Its ergonomic stand offers height, tilt, and swivel adjustments for comfortable viewing. The slim bezel design gives it a modern look and maximizes screen space. Built-in gaming features like Crosshair and Black Stabilizer improve accuracy and visibility in competitive titles. The LG UltraGear 27″ 180Hz Curved Monitor is not only stylish but also reliable for long hours of use. It is ideal for gamers, streamers, and anyone who values speed and immersion. Ultimately, this monitor offers a perfect balance of performance, design, and comfort. Specifications: Display : 27″ VA Resolution : QHD (2560 x 1440) Refresh Rate : 180Hz Response Rate : 1ms GTG Curvature : 1000R
WiWU Waterproof Large Capacity Minimalist Backpack Business Laptop Backpack Bags with Multi-Pockets For digital gadgets Minimalist Style Water-resistant material,Polyester Large Capacity Have Stock Size:15.6 inch
The MSI G242C Gaming Monitor delivers immersive visuals with a 23.6″ curved display and Full HD resolution. It enhances gameplay with a 1500R curve that wraps around your field of view. Moreover, the monitor features a 170Hz refresh rate and 1ms response time for smooth motion. This improves clarity in fast-paced games. It uses a VA panel with high contrast and wide viewing angles. This ensures deeper blacks and consistent colors from different positions. Adaptive Sync support helps reduce screen tearing and stuttering. This provides a smoother and more stable gaming experience. The monitor also includes anti-flicker and low blue light features. These help reduce eye strain during long sessions. The MSI G242C Gaming Monitor is a solid choice for users who want curved immersion and smooth performance. Specifications: 23.6″ Full HD curved VA panel with 1500R curvature 170Hz refresh rate for smooth and responsive gameplay 1ms (MPRT) response time for reduced motion blur Adaptive Sync support to eliminate screen tearing Anti-flicker and low blue light technology for eye comfort
Are you seeking a versatile solution for your presentation and collaboration needs? Look no further than the BenQ RE03A 75″ Board Essential. This cutting-edge interactive whiteboard redefines productivity and engagement in meeting rooms and classrooms alike. With its expansive 75-inch display, the BenQ RE03A offers ample space for showcasing your ideas and content. Whether you’re delivering a presentation, brainstorming with colleagues, or teaching a class, this interactive board provides a captivating canvas for your creativity. Transitioning to functionality, the BenQ RE03A boasts intuitive touch controls that make navigation and interaction effortless. Its responsive touch technology ensures smooth and precise input, allowing you to annotate, draw, and manipulate content with ease. Furthermore, the board’s seamless connectivity options enable seamless integration with your existing devices and software. Whether you’re using a laptop, tablet, or smartphone, the BenQ RE03A ensures compatibility and flexibility for all your presentation needs. In addition, collaboration features such as screen sharing and real-time annotation foster teamwork and idea exchange among participants. Break down communication barriers and enhance productivity with the BenQ RE03A’s collaborative tools. Moreover, the board’s durable construction and anti-glare surface ensure reliability and visibility even in brightly lit environments. Say goodbye to distractions and glare, and hello to clear, crisp visuals every time. In conclusion, the BenQ RE03A 75″ Board Essential is a game-changer for presentations and collaboration. With its large display, intuitive controls, and collaborative features, it empowers users to deliver impactful presentations and foster teamwork like never before. Upgrade your meeting room or classroom with the BenQ RE03A and unlock new possibilities for productivity and engagement. Specifications: Screen Size : 75″ Panel Type : IPS Resolution : UHD 3840×2160 Response Time : 8ms
The LG 27U511SA-W 27″ FHD IPS Smart Monitor with Speakers is built for comfortable viewing, entertainment, and everyday productivity. Its 27-inch Full HD IPS display delivers clear visuals and consistent colors, making it suitable for work, streaming, and browsing. Moreover, the IPS panel ensures wide viewing angles so images remain accurate from different positions. This smart monitor allows direct access to streaming apps without requiring a connected PC. Additionally, the built-in speakers provide convenient audio for movies, meetings, and casual gaming without external devices. The slim and modern design fits easily into home or office environments while keeping your workspace clean and organized. Connectivity options allow easy connection to laptops, consoles, and media devices. Furthermore, ergonomic adjustments help users maintain comfortable viewing positions during long sessions. Therefore, the monitor suits home users, students, and professionals seeking versatility and convenience. Finally, it combines smart functionality, quality visuals, and built-in sound for daily entertainment and productivity needs. Specifications: 27-inch Full HD IPS smart monitor Built-in speakers for convenient audio Smart features for direct streaming access Wide viewing angles with accurate colors Modern design with versatile connectivity
Speaker Specifications Feature Value Feature Value Input/Output USB Battery Capacity (mAh) 2000 Maximum Wireless Range (m) 10m-20m Touch Screen No Sound Mode Immersive, Stereo, Live, Standard Category Speakers Use HOME Bluetooth Version 5.1 Input Power (W) 50-99W Voice Control No Frequency Range 100Hz-20KHz Display Screen No Waterproof Yes Support APP No Support Memory Card Yes Playback Function Radio, MP3 Remote Control No Intelligent Personal Assistant None Display Screen No Audio Crossover Full-Range Number of Loudspeaker Enclosures 2 Power Source Battery Channels 1 Speaker Type Portable Communication USB Cabinet Material Plastic Brand Name HONOURSACY Origin Mainland China Function HiFi Sound Quality Function2 IPX6 Waterproof Function3 Support TWS Interconnection Function4 Portable Design Function5 80W High Power Function6 Long Endurance
The Samsung Odyssey G30D 27″ FHD 180Hz Gaming Monitor delivers smooth, fast visuals for games and everyday use. Its Full HD (1920×1080) resolution shows clear detail in games, videos, and work. The 27-inch screen gives you a large viewing area for wide action and immersive gameplay. This helps you see more and stay focused. Moreover, the Samsung Odyssey G30D 27″ FHD 180Hz Gaming Monitor features a high 180 Hz refresh rate. This high refresh rate makes motion fluid and clean on screen. Fast games and action scenes appear more detailed and responsive. In addition, the monitor offers a rapid 1 ms (MPRT) response time. This helps reduce ghosting and keeps fast visual shifts clear. Controls and movement feel precise and snappy. This enhances gameplay performance in fast shooters or racing games. Furthermore, the Samsung Odyssey G30D 27″ FHD 180Hz Gaming Monitor uses a VA panel with strong contrast (3000:1) and decent brightness (250 cd/m²). This delivers deeper blacks and vivid colors, improving visual quality for games and movies. It also covers around 95% sRGB for solid color representation. Also, the monitor supports adaptive sync with AMD FreeSync to reduce screen tearing and stutter when paired with compatible graphics cards. A slim 3-sided borderless design gives a clean modern look, and the ergonomic stand allows height, tilt, and swivel adjustments for comfortable use. Overall, the Samsung Odyssey G30D 27″ FHD 180Hz Gaming Monitor offers strong value by combining speed, clarity, and comfort. It suits gamers and everyday users who want smooth gameplay, responsive controls, and a clear large display. It is a solid choice for fast-paced games, casual gaming, and general computer use. Specifications: Display : 27″ VA Resolution : FHD (1920 x 1080) Refresh Rate : 180Hz Response Time : 1ms
The Samsung 32″ Essential S3 Curved Monitor LS32D392GAMXUE features a 32-inch VA panel with Full HD resolution (1920 × 1080). It uses a 1500R curved screen design that follows the natural field of view for a more immersive viewing experience. The monitor supports a refresh rate of up to 100Hz. As a result, motion appears smoother during everyday work, video playback, and casual gaming. In addition, the 4ms GTG response time helps reduce motion blur during fast-moving content. Samsung uses a VA panel with a typical 3000:1 contrast ratio and 250 cd/m² brightness. Therefore, the display delivers deeper blacks and improved contrast compared to many standard IPS and TN panels. The monitor also covers up to 95% of the sRGB color space. Eye Saver Mode and Flicker Free technology help reduce eye strain during extended use. Also, Game Mode adjusts image settings to improve visibility in darker scenes. Connectivity includes one HDMI 1.4 port, one D-Sub (VGA) port, and a headphone output. The monitor supports VESA 75 × 75 mm wall mounting and tilt adjustment from -2° to 22°. This model focuses on everyday productivity, media consumption, and general home use while providing a large curved display and higher-than-standard refresh rate. Specifications: 32-inch VA panel with Full HD (1920 × 1080) resolution 1500R curved screen design Up to 100Hz refresh rate 4ms GTG response time HDMI 1.4, D-Sub (VGA), and headphone connectivity
Keyboard for Macbook Pro A1502 ,A1582,A1493 13" Inch Retina Year 2013,2014,2015 Part no ME864 ME864LL/A ME866LL/A APN: 661-8154, 661-02361, 818-4278 Black US Layout Keyboard for Macbook Pro A1502 ,A1582,A1493 13″ Inch Retina Year 2013,2014,2015 Part no ME864 ME864LL/A ME866LL/A APN: 661-8154, 661-02361, 818-4278 Black US Layout Compatibility: FOR MB Pro Retina 13″ A1502 Late 2013: ME864LL/A (2.4 Core i5) Late 2013: ME866LL/A (2.6 Core i5) Late 2013: ME866LL/A (2.8 Core i7) Mid 2014: MGX72LL/A (2.6 Core i5) Mid 2014: MGX92LL/A (2.8 Core i5) Mid 2014: MGX92LL/A (3.0 Core i7) Early 2015: MF839LL/A (2.7 GHz Core i5) Early 2015: MF841LL/A (2.9 GHz Core i5) Early 2015: MF843LL/A (3.1 GHz Core i7) Identifying Numbers APN: 661-8154, 661-02361, 818-4278 Compatible part numbers: ME864 ME865 ME866 MF839 MF841 MF843 MGX72 MGX92 (Layout US) Related Part #: 661-8154, 661-02361, 818-4278 High Quality Laptop Keyboard. 100% Compatible with your brand.
The MSI MAG 244F 24″ 200 Hz Gaming Monitor delivers smooth visuals with super‑fast refresh rate. It features a full HD (1920×1080) IPS panel for vivid colors and wide viewing angles. Moreover, its 1 ms MPRT response time reduces motion blur during fast-paced gameplay. Also, the 200 Hz refresh rate ensures fluid motion in competitive games. In addition, the monitor supports Adaptive‑Sync to eliminate screen tearing and stutter. Besides that, the slim bezel design creates an immersive multi‑monitor setup. Furthermore, the adjustable stand allows tilt, height, and swivel customization. Therefore, users can find a comfortable viewing position effortlessly. It includes DisplayPort and HDMI inputs for flexible connectivity. Also, built‑in gaming presets offer easy optimization for different game genres. Plus, MSI’s Anti‑Flicker and Less Blue Light technologies reduce eye strain. Meanwhile, the monitor uses a VESA mount for wall or arm installation. Importantly, the sturdy stand delivers stable support during intense gaming sessions. Also, on‑screen crosshair overlays enhance accuracy in FPS games. Unlike standard monitors, this one targets e‑sports and fast‑reaction players. However, it still works well for streaming, editing, and productivity tasks. For example, racing, shooter, or fighting games feel more responsive and clear. Then, users connect cables, power on, and enjoy lag‑free visuals instantly. Moreover, the ergonomics support comfort during long gaming or desk sessions. As a result, performance gains combine with healthy posture support. Also, the display’s vivid contrast keeps dark and bright details visible. In addition, its low input lag provides competitive advantage in fast games. Therefore, gamers stay ahead with accurate and real‑time feedback. Also, the monitor’s sleek black design complements any gaming setup. Furthermore, MSI’s reliable build quality offers long‑term durability. Consequently, users gain both style and substance in one package. Also, all essential cables come in the box for easy setup. In conclusion, the MSI MAG 244F offers 200 Hz speed, IPS clarity, and gaming comfort. Finally, it’s a smart investment for serious gamers seeking fluid performance. Specifications: Display : 23.8” Rapid IPS Resolution : 1920 x 1080 (FHD) Refresh Rate : 200Hz Response Rate : 0.5ms
Genuine-spec battery flex cable for MacBook Pro models A2159 (16", 2019), A1708 (13", 2016–2017), and A2338 (13", 2020 M1)—restores critical communication between the battery and logic board for proper power-on, charging, and macOS battery status. Genuine-spec battery flex cable for MacBook Pro models A2159 (16″, 2019), A1708 (13″, 2016–2017), and A2338 (13″, 2020 M1)—restores critical communication between the battery and logic board for proper power-on, charging, and macOS battery status. Carries SMBus (System Management Bus) signals from the battery to the logic board Enables: Accurate battery percentage and health reporting in macOS Proper charging control (start/stop, thermal throttling) Power-on capability (MacBooks will not boot without this connection) Prevention of “Battery Not Charging” or “Service Battery” errors Accurate battery percentage and health reporting in macOS Proper charging control (start/stop, thermal throttling) Power-on capability (MacBooks will not boot without this connection) Prevention of “Battery Not Charging” or “Service Battery” errors MacBook won’t turn on (even with a good battery) Battery shows “–%”, 0%, or “Not Charging” Random shutdowns under load macOS displays “No Battery Available” Logic board powers fans or lights but no display output Battery flex cable only (with OEM-style connector and strain relief) ❌ Does not include: battery, logic board, or trackpad Requires full bottom case removal and battery disconnection Connects via a ZIF or press-fit socket on the logic board Must be routed precisely to avoid tension or micro-tears Highly recommended for experienced or certified technicians—improper installation can cause permanent power or battery communication failure
Genuine-spec keyboard replacement for MacBook Pro 13″ (Model A2289, 2020) — available in US QWERTY or UK QWERTY (with £ symbol). Features Apple’s scissor-switch Magic Keyboard, backlighting, and OEM-fit design for reliable performance and seamless installation. Compatible With: MacBook Pro 13-inch (2020, Four Thunderbolt Ports, Model A2289, Model Identifier MacBookPro16,2) with Intel Core i5/i7 processors. Layout Options (select at purchase): US Layout: Standard QWERTY with wide Enter key, @ above 2, and # above 3. UK Layout: QWERTY with £ symbol, tall vertical Enter key, @ on right Alt, and UK-specific punctuation. US Layout: Standard QWERTY with wide Enter key, @ above 2, and # above 3. UK Layout: QWERTY with £ symbol, tall vertical Enter key, @ on right Alt, and UK-specific punctuation. Keyboard Type: Apple’s Magic Keyboard with scissor-switch mechanism—quieter, more stable, and more durable than earlier Butterfly designs. Integrated Features: Full backlighting for low-light use Ambient light sensor compatibility OEM-style flex cable pre-attached for direct logic board connection Full backlighting for low-light use Ambient light sensor compatibility OEM-style flex cable pre-attached for direct logic board connection Build & Fit: Engineered to exact Apple specifications—ensures perfect alignment, consistent key height, and flush integration into the original top case. Installation Note: Keyboard is glued into the top case and requires full disassembly, careful adhesive removal, and professional re-adhesion. Recommended for experienced or certified technicians only.
The ViewSonic VA24D1-H 24″ FHD 100Hz Monitor delivers smooth and clear visuals for work, gaming, and daily use. It offers Full HD resolution with bright colors. The screen shows sharp details that improve movies, documents, and web browsing. This makes your viewing experience more comfortable. Moreover, the ViewSonic VA24D1-H 24″ FHD 100Hz Monitor includes a fast 100Hz refresh rate. This feature reduces motion blur and screen tearing. It makes gaming and fast scenes much smoother. It also improves general tasks like scrolling and tracking movement. In addition, the monitor features HDMI and VGA connections. These ports make setup quick and simple. You can connect laptops, desktops, and media players easily. This gives you strong flexibility for work and entertainment. Furthermore, the ViewSonic VA24D1-H 24″ FHD 100Hz Monitor includes important eye-care technology. The flicker-free screen helps reduce eye strain. The blue light filter adds more comfort during long hours. This makes the monitor ideal for study, office work, and long sessions. Also, the slim bezel design gives the monitor a modern and clean look. It fits well in home and office spaces. The thin edges help create smooth multi-monitor setups. This improves both productivity and style. The stand on the ViewSonic VA24D1-H 24″ FHD 100Hz Monitor offers stable support. You can tilt the screen to find a comfortable angle. This helps you maintain a healthy posture. It also improves your overall viewing comfort. Overall, the ViewSonic VA24D1-H 24″ FHD 100Hz Monitor offers clarity, smooth motion, and strong comfort. It works well for gaming, streaming, office tasks, and daily use. It is a reliable monitor for users who want simple performance and modern design. Specifications: Display : 24″ IPS Resolution : 1920×1080 Refresh Rate : 100Hz Response Time : 5ms
PCE 1500 M8 1500VA 600W PCE UPS SYSTEM M8-1500 1500VA 600W Input Voltage: 220/230/240 VAC, 1Ø2Wires Input Frequency: 50 or 60 Hz +/-10% (auto sensing) Power: 600W Output voltage: 220/230/240VAC+/-1% Output Frequency: 50 or 60 Hz +/-1% Full Protection: Overload, discharge, and overcharge protection PCE UPS SYSTEM M8-1500 1500VA 600W Input Voltage: 220/230/240 VAC, 1Ø2Wires Input Frequency: 50 or 60 Hz +/-10% (auto sensing) Power: 600W Output voltage: 220/230/240VAC+/-1% Output Frequency: 50 or 60 Hz +/-1% Full Protection: Overload, discharge, and overcharge protection
