Imagine coming home after a long day, hands full of groceries, only to realize you forgot your keys. Or worse—missing a critical delivery because you were in the shower when the courier rang. Traditional doorbells leave you guessing, but today’s smart solutions put control firmly in your pocket. Battery-powered video doorbells have evolved from niche gadgets to essential home security tools, offering unprecedented flexibility without the hassle of complex wiring. By 2026, these devices aren’t just about convenience; they’re gatekeepers that learn your routines, deter unwanted visitors, and integrate seamlessly with the rest of your connected home, all while operating reliably for months on a single charge.
Gone are the days when installing a doorbell meant calling an electrician or wrestling with exposed wires. The latest generation of battery-powered models empowers anyone—renters, homeowners, tech novices—to enhance their doorstep security in under 30 minutes. With advancements in battery chemistry, AI-powered motion detection, and crystal-clear video, these devices now deliver performance that rivals hardwired systems. Whether you’re safeguarding a historic apartment, a modern farmhouse, or a vacation home, understanding the key features that define 2026’s top contenders is crucial. Let’s cut through the marketing noise and focus on what truly matters for a reliable, user-friendly experience at your front door.
Top 10 Battery-Powered Doorbells
Detailed Product Reviews
1. AVANTEK Wireless Door Bell, BA-11 Waterproof Battery Operated Doorbell Chime Operating at 1000 Feet, Portable Door Chime kit with 52 Melodies, 5 Volume Levels, and CD Quality Sound
Overview: The AVANTEK BA-11 is a compact, battery-powered wireless doorbell system designed for reliable visitor alerts with an impressive 1000-foot range. Ideal for homes without nearby outlets, it offers extensive customization and robust weather resistance. What Makes It Stand Out: Its standout features include a substantial 1000-foot wireless range ensuring coverage across large properties, CD-quality sound from a 29mm stereo speaker delivering crisp 120dB audio, and an exceptional IP55 waterproof/dustproof rating allowing the transmitter to endure extreme temperatures (-4°F to 140°F). The 52 melody options and memory function for settings retention after battery changes enhance user convenience. Value for Money: Priced competitively, it offers premium features like superior range and sound quality typically found in more expensive models. The inclusion of AAA batteries for the receiver and a long-lasting CR2032 transmitter battery (advertised 3-year life) adds tangible value over basic kits. Strengths and Weaknesses: Strengths: Ultra-long range, excellent weather resistance, rich sound quality, extensive melody selection, and memory function. Weaknesses: Receiver requires frequent AAA battery changes (not specified lifespan), and the compact size might feel less substantial than bulkier alternatives. Bottom Line: An excellent choice for those prioritizing range, sound quality, and durability in harsh conditions, offering significant features for its price point, though anticipate regular receiver battery replacements.
2. TECKNET Longest 1300 Feet Wireless Doorbell with RGB Alarm Lighting,Battery-Powered IP66 Waterproof Design,60+Chimes & 5-Level Volume for Home/Apartment/Classroom/Business,4.5-Year Battery Life,White
Overview: TECKNET’s long-range doorbell boasts a claimed 1300-foot wireless signal and unique RGB lighting, targeting users needing visual alerts alongside sound, especially beneficial for hearing-impaired individuals or noisy environments. What Makes It Stand Out: The standout elements are the industry-leading 1300-foot open-range coverage, the customizable RGB light indicator that flashes brightly for visual notification (crucial for silent mode), and an impressive advertised 36-month receiver battery life using a sleep mode feature. The 60 melodies and 110dB max volume provide ample customization. Value for Money: It delivers exceptional value for large properties or commercial use with its vast range and visual alert system. The long battery life reduces maintenance costs, though the receiver requires separate AA batteries (not included), slightly increasing initial setup expense compared to kits with included power sources. Strengths and Weaknesses: Strengths: Unmatched range, effective RGB visual alert, long receiver battery life, 60 melody choices, and IP66 weatherproofing. Weaknesses: Receiver batteries not included, IP66 rating is slightly less robust than IP67 alternatives, and maximum volume is marginally lower than some competitors. Bottom Line: Highly recommended for spacious homes, classrooms, or users needing visual alerts, offering top-tier range and innovative features that justify its price, especially for accessibility-focused setups.
3. TECKNET Wireless Doorbell 1312FT, IP67 Waterproof Classroom Doorbell Battery-Powered Door Bell, 60 Chimes 5-Level Volume, 4.5-year Battery Life, Electric Doorbells No Plug-in Required for Home
Overview: This TECKNET model pushes range and durability further, featuring a 1312-foot signal, superior IP67 waterproofing, and an industry-leading 4.5-year transmitter battery life, positioning it as a premium, low-maintenance solution. What Makes It Stand Out: Key differentiators are the extreme 1312-foot range with anti-interference, the higher IP67 rating (vs. IP66) ensuring resilience against heavy rain/snow, and the remarkable 4.5-year advertised transmitter battery life. Silent mode with bright LED notification caters perfectly to classrooms or quiet zones. Value for Money: It commands a slight premium but justifies it with unparalleled durability (IP67), exceptional battery longevity, and reliable long-range performance. The value shines for users in harsh climates or seeking minimal battery replacement hassle over years. Strengths and Weaknesses: Strengths: Best-in-class IP67 weatherproofing, longest battery life (4.5 years), robust 1312ft range, versatile silent mode with LED, and 60 melodies. Weaknesses: Receiver still requires separate AA batteries, and the ultra-long battery life claim is highly dependent on usage frequency. Bottom Line: The top pick for extreme weather resilience and ultra-low maintenance, ideal for rural properties, workshops, or anyone prioritizing longevity and reliability over absolute lowest cost.
4. GE Wireless Doorbell Kit,Battery-Operated Receiver,1 Push Button door bell,2 Melodies,4 Volume Levels doorbell chime,classroom doorbell,150 Ft Range,Mountable,White,19247
Overview: The GE 19247 is a no-frills, entry-level wireless doorbell kit focused on simplicity and reliability for small to medium homes, featuring basic functionality with a modest 150-foot range. What Makes It Stand Out: It stands out through sheer simplicity and trusted branding. Pre-paired components enable instant setup, and its classic “ding dong” and Westminster melodies offer familiar, unobtrusive alerts. The ability to pair multiple buttons/receivers (up to 4 each) adds flexible scalability for small offices or multi-door homes. Value for Money: Offers solid value as a budget-friendly, reliable solution for basic needs. Its low price point is attractive, though the limited 2 melodies, 150ft range, and lack of modern features (like visual alerts or extensive volume control) make it less compelling against more feature-rich options at similar price points. Strengths and Weaknesses: Strengths: Extremely easy setup, reliable basic operation, classic aesthetic, scalable with multiple units, and affordable. Weaknesses: Very limited range (150ft), only 2 melodies, no visual alert option, and receiver batteries not included. Bottom Line: A dependable, straightforward choice for apartment dwellers or small homes where simplicity and low cost are paramount, but lacks the features and range needed for larger or more demanding environments.
5. Philips Wireless Doorbell Kit, Battery-Operated Reciever, 1 Push Button, 2 Melodies, 4 Volume Levels, 150 Ft Range, White, DES1120W/27
Overview: Nearly identical to the GE model, the Philips DES1120W/27 is a minimalist wireless doorbell kit offering core functionality with a 150-foot range, targeting users seeking fuss-free installation and operation. What Makes It Stand Out: Its distinction lies in Philips’ reputable build quality and the identical core simplicity as the GE kit: pre-paired operation, classic melodies (ding dong, Westminster), and the useful multi-unit pairing capability (4 buttons/receivers per unit). It emphasizes reliability over innovation. Value for Money: Positioned as a budget staple, it provides good value for basic needs at a competitive price. However, like the GE, its value is diminished by the short range and lack of features (visual alerts, extensive melodies) increasingly common in entry-level models, making alternatives more appealing for marginal cost differences. Strengths and Weaknesses: Strengths: Plug-and-play setup, dependable performance, clean classic design, scalable configuration, and low initial cost. Weaknesses: Severely limited 150ft range, only 2 melody options, no visual notification, and receiver requires separate AA batteries. Bottom Line: A competent, no-nonsense option for very small spaces where absolute basics suffice, but the Philips/GE similarity and feature limitations mean most users should consider more capable models unless simplicity is the absolute priority.
6. AIDA Lighted Wireless Doorbell for Home, Waterproof Battery Doorbell Wireless 1,000ft Range, 5 Volume Levels with 58 Chimes & LED Flash on Receiver (White, 2 Buttons & 1 Receiver)
Overview: The AIDA Lighted Wireless Doorbell offers robust outdoor coverage with a 1,000ft range, IP55 waterproofing, and dual-button flexibility. Ideal for multi-entry homes or offices, it ensures reliable alerts through harsh weather using battery-powered components and visual LED cues.
What Makes It Stand Out: Its 1,000ft range penetrates walls/floors effortlessly, while the IP55-rated button withstands extreme temperatures (-10°C to 50°C). The 58 chime options, 5 volume levels (up to 110dB), and mute-mode LED flash cater to diverse needs—from households with sleeping babies to hearing-impaired users. Smart memory retains settings post-power-outage.
Value for Money: Priced mid-range, it outperforms budget models with superior range and durability. The included batteries, dual buttons, and 1-year warranty with lifetime support justify the cost, especially compared to single-button competitors lacking weatherproofing or extensive chime libraries.
Strengths and Weaknesses:
Strengths: Exceptional range; reliable all-weather performance; versatile chime/volume options; mute-mode LED; easy setup.
Weaknesses: Receiver requires outlet power (less portable); no multi-receiver pairing; volume max may be too loud for small spaces.
Bottom Line: A top pick for large homes needing weather-resistant, feature-rich alerts. The dual buttons and LED flash solve common pain points, making it worth the investment for reliable visitor notifications.
7. Philips Wireless Doorbell Kit, Battery-Operated Reciever, LED Alert Lights, 1 Push Button, 32 Melodies, 3 Volume Levels, 150 Ft Range, White, DES3140W/27
Overview: Philips’ minimalist doorbell kit focuses on simplicity and portability, featuring a compact receiver with LED alerts, 32 melodies, and a 150ft range. Designed for small spaces, it’s ideal for apartments or temporary setups like offices or garages.
What Makes It Stand Out: The dual LED rings on both receiver and button provide subtle visual alerts—perfect for noisy environments or light sleepers. Its ultra-portable receiver (no outlet needed) and ability to pair with up to 4 buttons/receivers offer unmatched flexibility for multi-room use.
Value for Money: Budget-friendly but limited by its short 150ft range. Best for small homes; cheaper than AIDA/TECKNET but lacks weatherproofing and range. You sacrifice durability for portability, though the 32 melodies add charm at this price point.
Strengths and Weaknesses:
Strengths: Highly portable receiver; intuitive multi-device pairing; gentle LED alerts; no wiring needed.
Weaknesses: Very limited range (150ft); button lacks waterproofing; volume capped at 95dB; AA batteries not included.
Bottom Line: Opt for this only in compact spaces where portability trumps range. It’s a charming, no-fuss solution for apartments but fails for larger or outdoor-heavy setups.
8. TECKNET Wireless Doorbell, Door Bell 0-120dB, Battery-Powered 1300ft Range, Classroom Doorbells IP66 Waterproof, 60 Chimes & 5 Volume Levels, RGB Light for Home Kids Classroom Hearing Impaired, white
Overview: TECKNET delivers industrial-grade performance with a 1,300ft range, IP66 waterproofing, and 36-month battery life. Tailored for classrooms or large properties, it combines extreme durability with customizable alerts via RGB lights and 60 chimes.
What Makes It Stand Out: Unbeatable 1,300ft range penetrates thick walls, while IP66 sealing handles downpours or freezing temps (-20°C to 60°C). The 36-month battery life (thanks to sleep mode) and triple working modes (LED/ringer/both) cater to hearing-impaired users or noise-sensitive zones like nurseries.
Value for Money: Premium-priced but justified for large estates or commercial use. Outranges AIDA by 300ft, with better waterproofing (IP66 vs. IP55) and longer battery life. Cheaper than smart video doorbells while offering superior reliability for basic alerts.
Strengths and Weaknesses:
Strengths: Industry-leading range; exceptional weather resistance; ultra-long battery life; versatile alert modes; 60 chimes.
Weaknesses: Receiver requires non-included AA batteries; complex mode-switching; RGB light can feel gimmicky.
Bottom Line: The ultimate choice for rural homes, schools, or harsh climates. Its durability and range eliminate missed visitors, making it a smart long-term investment.
9. Ring Battery Doorbell (newest model), Home or business security with Head-to-Toe video, Live View with Two-Way Talk, and Motion Detection & Alerts, Venetian Bronze
Overview: Ring’s Battery Doorbell transcends traditional chimes with HD video, two-way talk, and motion alerts. This smart security device replaces audio-only doorbells, offering real-time remote monitoring via smartphone for homes or businesses.
What Makes It Stand Out: Head-to-toe video (66% more coverage) captures full visitor height, while USB-C charging and customizable motion zones provide user-friendly security. Live View and two-way talk let you interact remotely—critical for package safety or verifying陌生 visitors.
Value for Money: Pricier than audio-only models but delivers comprehensive security. Avoids wiring hassles, and subscription-free motion alerts add value. Competes with pricier systems (e.g., Nest) by balancing features and cost, though advanced analytics require a Ring Protect plan.
Strengths and Weaknesses:
Strengths: Excellent video coverage; intuitive app integration; no wiring; USB-C convenience; robust motion alerts.
Weaknesses: Battery requires frequent recharging (1-2 months); subscription needed for video history; limited to Wi-Fi range.
Bottom Line: Essential for tech-savvy users prioritizing security over simplicity. Worth the cost if video verification and remote access are non-negotiable.
10. Wireless Doorbells for Home Battery Operated Doorbell at 1200 Feet with Flashing Light 36 Melodies 4 Volume Levels (2 Portable Receivers & 1 Touch Button White）JSIEEM
Overview: JSIEEM’s kit offers dual portable receivers and a touch-button transmitter with 1,000ft range. Focused on mobility, it targets users needing alerts in multiple zones (e.g., backyard + bedroom) without outlet dependency.
What Makes It Stand Out: Two battery-powered receivers (AAA included) enable simultaneous alerts in separate areas, while the IP44-rated touch button balances weather resistance and sensitivity. The large LED flash aids hearing-impaired users, and 36 melodies provide basic personalization.
Value for Money: Affordable for the dual-receiver setup, undercutting AIDA/TECKNET. Ideal for renters or small homes wanting multi-room coverage without complex installation. However, the 1,000ft claim is optimistic indoors—it matches Philips in real-world use but lacks their polish.
Strengths and Weaknesses:
Strengths: Two portable receivers; touch-button ease; strong LED visibility; simple mute mode; budget-friendly.
Weaknesses: Range overstated (1,000ft only in open areas); button not fully waterproof; melodies feel dated; no temperature resilience.
Bottom Line: A solid budget option for multi-room alerts in mild climates. Choose this for portability and dual receivers, but avoid for extreme weather or large properties.
Understanding Modern Battery-Powered Doorbell Essentials
Why Battery Power Dominates Home Security Upgrades
Battery operation removes the biggest barrier to entry: installation complexity. Renters can deploy these systems without landlord permission, homeowners avoid drilling into walls for wiring, and seasonal property owners benefit from easy setup during visits. Modern lithium-based batteries now support extended operational periods, often 4-6 months or more under typical use, making them a practical “set and forget” solution. This shift toward wireless convenience aligns perfectly with the rise of DIY home security, putting control directly in the user’s hands without compromising on essential features.
Core Technology Driving 2026 Innovations
Significant leaps in low-power chipsets and energy-efficient sensors are extending battery life while boosting performance. Advanced image sensors capture sharper footage in near-total darkness, and AI processors embedded directly on the device reduce false alerts by distinguishing between passing cars, stray animals, and actual visitors. Enhanced wireless protocols ensure stable connections to your home network even in challenging environments, eliminating frustrating dropouts. These under-the-hood improvements mean today’s battery doorbells deliver enterprise-grade reliability in a compact, user-friendly package.
Key Features to Prioritize When Choosing
Video Quality and Field of View Considerations
Look beyond basic HD specs. Models offering 2K or higher resolution provide critical detail for identifying faces or license plates, especially when zooming digitally. A wide field of view (150-180 degrees) minimizes blind spots, capturing package thieves approaching from the side. Crucially, verify low-light performance—true color night vision using ambient light or subtle infrared illumination ensures usable footage at midnight, not just grainy black-and-white images. Check if the device maintains resolution during motion-triggered recordings, not just live view.
Motion Detection Precision and Customization
Generic motion alerts flooding your phone defeat the purpose of smart security. Seek systems with customizable activity zones—draw virtual boundaries around your porch while ignoring the sidewalk. Advanced AI should classify motion types (person, vehicle, package) and trigger relevant alerts. Adjustable sensitivity prevents wind-blown leaves or headlights from causing false alarms. Some premium models even offer “motion tracking,” panning the camera to follow a visitor as they approach your door, ensuring they stay in frame.
Two-Way Audio Clarity and Range
Clear communication is non-negotiable. Test audio samples for crisp, lag-free conversation—static or delay makes remote chats frustrating. Ensure the microphone effectively picks up voices through wind or light rain. Consider speaker volume; it needs to be audible over background noise if you’re speaking to someone from another room. Bonus points for noise cancellation that filters out street sounds so your voice comes through cleanly to the person outside.
Installation and Usability Factors
Simplified Mounting Process Requirements
True DIY ease means no special tools beyond a screwdriver. Look for peel-and-stick adhesive mounts for temporary placement or quick swaps, alongside traditional screw options for permanence. Magnetic mounting systems are gaining popularity for effortless repositioning or removal. Verify the baseplate design—some allow you to detach just the camera for charging while keeping wiring hidden, maintaining security during battery swaps. Clear, visual installation guides within the companion app are essential for first-time users.
Battery Life Expectations and Management
Don’t trust marketing claims blindly. Real-world battery life varies drastically based on usage: frequent motion events, constant live viewing, cold temperatures, and video resolution settings all drain power faster. Prioritize models with user-replaceable batteries—avoiding the need to send the entire unit for servicing. Smart battery indicators showing estimated days remaining (not just a percentage) prevent unexpected downtime. Some 2026 models integrate solar charging docks as optional accessories, effectively making battery life indefinite in sunny climates.
Connectivity and Smart Home Integration
Wireless Protocol Reliability (Wi-Fi 6/6E and Beyond)
Stable connectivity is the backbone of performance. Devices leveraging Wi-Fi 6 or 6E handle network congestion better and maintain connections farther from your router—critical for detached garages or large properties. Check compatibility with your home network band (2.4GHz is essential for range; 5GHz offers speed but shorter reach). Avoid models locked to proprietary hubs; direct Wi-Fi connection simplifies setup and reduces failure points. Strong signal strength indicators during installation setup prevent future connectivity headaches.
Ecosystem Compatibility and Voice Control
Your doorbell should speak the language of your existing smart home. Verify seamless integration with major platforms like Apple HomeKit, Google Home, and Amazon Alexa for unified control. True “works with” certification ensures reliable voice commands (“Hey Google, show me the front door”) and automations (e.g., “Turn on porch light when doorbell detects motion after sunset”). Prioritize open standards like Matter for future-proofing, allowing your doorbell to interact smoothly with emerging devices regardless of brand.
Security and Privacy Protections
Data Encryption Standards for Peace of Mind
Video footage is highly sensitive. Insist on end-to-end encryption (E2EE) that secures video both in transit and while stored in the cloud. This means even the manufacturer can’t access your recordings—a vital layer against breaches. Look for physical privacy indicators (like an LED light) that show when the camera is active. Avoid services with vague privacy policies; prioritize companies with clear, transparent data handling practices and no history of major security lapses.
Local Storage Options Versus Cloud Subscriptions
While cloud storage offers convenience, it often requires ongoing subscription fees. Investigate models supporting local storage via microSD cards—giving you full ownership of footage without monthly costs. If opting for cloud, understand the retention period (24 hours vs. 30 days) and whether event-based recording (saving only when motion is detected) is included. Some 2026 systems offer hybrid solutions, storing recent clips locally with optional cloud backup, providing flexibility based on your budget and privacy needs.
Environmental Durability and Longevity
Weather Resistance Ratings Demystified
Your doorbell faces sun, rain, snow, and dust daily. An IP65 or higher rating is non-negotiable—it guarantees protection against water jets and dust ingress. Don’t confuse this with “weather-resistant” marketing fluff; check the specific IP (Ingress Protection) code. For extreme climates (desert heat or sub-zero winters), verify the manufacturer’s stated operating temperature range. Some premium models now include internal heating elements to prevent camera lens fogging in cold, humid conditions.
Physical Build Quality and Tamper Resistance
A flimsy plastic casing won’t deter determined thieves. Look for robust construction using UV-stabilized materials that won’t yellow in sunlight. Tamper-proof screws or hidden mounting hardware make physical removal difficult. Some advanced models trigger instant alerts if someone tries to unplug or forcibly detach the unit. Consider if the design includes anti-reflective coating on the lens to prevent glare from interfering with the camera’s view.
User Experience and Maintenance
Intuitive Mobile Application Design
The companion app is your command center. It must be stable, fast, and logically organized—no one wants to hunt through menus during a delivery. Key features like quick access to live view, easy alert customization, and one-tap two-way talk are essential. Check recent app store reviews specifically mentioning interface frustrations. Offline functionality (viewing local storage or basic settings without internet) is a valuable bonus for troubleshooting.
Notification Management and Alert Fatigue Prevention
Getting bombarded with alerts defeats the purpose. Sophisticated notification systems let you prioritize critical events (a person at the door) over minor ones (a car driving by). Scheduling “quiet hours” for vacations or nighttime prevents disturbances. Look for apps allowing per-user notification preferences—so your teenager doesn’t get pinged for every leaf blow—but you do for package deliveries. Granular control turns alerts from a nuisance into a genuinely useful tool.
Future-Proofing Your Investment
Over-the-Air Update Capabilities
Technology evolves rapidly. Choose a brand with a proven track record of delivering regular, meaningful firmware updates that enhance features or security. Automatic over-the-air (OTA) updates ensure your device stays current without manual intervention. Check how long the manufacturer commits to supporting the model with updates—5+ years is ideal. Avoid “smart” devices from companies known for abandoning older hardware.
Expandability Within Security Ecosystems
Consider how the doorbell fits into your broader security vision. Can it trigger other actions, like turning on smart lights when motion is detected at night? Does it integrate with professional monitoring services if you later opt for that layer? Some systems allow adding compatible battery-powered cameras or sensors later, creating a cohesive perimeter defense without rewiring. Planning for expansion saves cost and complexity down the line.
Frequently Asked Questions
How long do batteries typically last in 2026 models?
Most premium models last 4-6 months under average use (10-20 events daily), but heavy usage or extreme cold can reduce this to 2-3 months. User-replaceable batteries and solar charger options significantly extend operational time.
Can battery doorbells work in freezing temperatures?
Yes, but performance varies. Lithium batteries lose capacity below 32°F (0°C). Look for models rated for sub-zero operation (e.g., -4°F/-20°C), which often include battery warming features. Expect reduced battery life in sustained cold.
Is a subscription mandatory for basic functionality?
No. Core features like live view, two-way talk, and motion alerts typically work without a subscription. Cloud storage, advanced AI detection, or extended video history usually require a paid plan, but local storage alternatives exist.
How secure are these devices against hacking?
Security depends on the brand. Prioritize models with end-to-end encryption (E2EE), regular firmware updates, and strong password requirements. Avoid devices with known security vulnerabilities or poor privacy practices.
Can I install a battery doorbell on a metal door?
Generally yes, but metal can interfere with Wi-Fi signals. Test placement during setup—move the doorbell slightly away from the metal surface if signal strength is weak. Magnetic mounts often help position the camera optimally.
Do they work with existing wired doorbell chimes?
Some models offer optional wired kits to connect to your home’s existing chime system, providing both in-home audio and smartphone alerts. Check compatibility before purchasing if this feature is important to you.
What happens when the battery dies suddenly?
Most apps provide low-battery warnings weeks in advance. If it dies unexpectedly, you’ll lose remote features but the physical doorbell button (if equipped) may still trigger your wired chime, if connected. Charging takes 2-4 hours.
Are solar chargers worth the extra cost?
For locations with consistent sunlight, solar chargers effectively eliminate battery changes, making them ideal for hard-to-reach doors or eco-conscious users. They’re less effective in shaded areas or extreme northern/southern latitudes during winter.
How do I prevent false motion alerts from street traffic?
Use the app to draw precise activity zones only covering your porch pathway. Enable AI-powered person/vehicle detection to filter out irrelevant motion, and adjust sensitivity sliders based on your environment.
Can I use two battery doorbells for front and back doors?
Absolutely. Most ecosystems support multiple doorbells or cameras under one account. Ensure your Wi-Fi network has adequate coverage at both locations, and check that the app allows easy switching between devices.