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Selecting an effective door and window alarm sensor setup requires balancing perimeter access points, hub compatibility, and physical installation needs across your property. Shoppers typically choose between standalone contact sensor packs designed to expand an existing security setup and comprehensive kits containing a central hub or secondary sensors. When looking for a eufy door sensor 3 pack, determining whether your home already has an active management hub or needs a complete starter package is the essential first step. Proper perimeter coverage ensures every vulnerable portal remains monitored without gaps or redundant hardware.
The eufy security catalog organizes door and window protection into modular add-ons and all-in-one equipment bundles. Individual units like the standard eufy entry sensor and the upgraded eufy entry sensor e20 provide flexible additions for established networks. Multi-packs like the eufy 3-pack entry sensor offer multi-portal protection for several openings at once. For entirely new installations, bundled configurations like the eufy homebase 3 with sensors or the eufy home alarm kit integrate entry triggers with sirens, storage hubs, or supplemental motion detectors.
eufy Door Sensors Lineup at a Glance
| Model | Pack Size | Battery Life | Hub Needed | Key Detection Features |
|---|---|---|---|---|
| eufy Security HomeBase3 S380 Hub+4-Pack Entry | 4 Sensors + 1 Hub | Up to 5 years | Included | Dual-side detection, bypass button, 100 dB siren |
| 3-Pack Entry Sensor by eufy | 3 Sensors | 730 days | Yes | Forced entry detection, 100 dB HomeBase siren |
| eufy Security Entry Sensor E20 | 1 Sensor | Up to 5 years | Yes | Dual-side detection, bypass button, 656 ft range |
| eufy Security Entry Sensor | 1 Sensor | 800 days | Yes | Open/closed detection, optional 24/7 service |
| eufy Security 5-Piece Home Alarm Kit | 5-Piece kit | Not specified | System kit | Contact sensors, motion sensor, keypad, 30 ft range |
| eufy Security Entry Sensor (Renewed) | 1 Sensor | 800 days | Yes | Open/closed detection, screw or tape mounting |
The Models in Detail
eufy Security HomeBase3 S380 Hub+4-Pack Entry
Check price on Amazon Our score: 8.8/10
Best for: Complete home coverage with centralized hub storage
Pros
- Includes HomeBase S380 hub
- Up to 5-year battery life
- Expandable local storage to 16 TB
- Convenient bypass button
Cons
- Hub and sensors may ship separately
The eufy Security HomeBase3 S380 Hub+4-Pack Entry bundle provides a complete perimeter defense package featuring four Entry Sensors E20 and a centralized HomeBase S380 hub. The four included battery-powered sensors allow homeowners to secure front, rear, and side entryways alongside vulnerable ground-level windows. Each sensor delivers up to five years of continuous operation and measures 2.88 by 1.54 by 0.85 inches. Built-in dual-side detection supports left- or right-hand door jamb mounting, while an integrated bypass button allows temporary portal opening without triggering alarms. The listing states that the sensors and HomeBase hub ship in separate retail boxes and may arrive on different days.
The included HomeBase S380 acts as the central security bridge, sounding an integrated 100-decibel siren and broadcasting chime alerts whenever a contact is broken. It includes 16 GB of built-in storage with zero monthly fees, expandable up to 16 TB with an external portable hard drive that is not included. Data is secured via AES-256-GCM and ECC-256 encryption, while BionicMind AI provides up to 99 percent facial recognition accuracy when paired with compatible security cameras. Requiring eufy app version 6.0.00 or above, this bundle is suited for users building a comprehensive eufy security door sensor network from scratch, though it represents unnecessary hardware if you already own a functional base station.
3-Pack Entry Sensor by eufy Each battery lasts for 730 days of monitoring
Check price on Amazon Our score: 9.0/10
Best for: Securing three portals without extra hub hardware
Pros
- Convenient 3-pack bundle
- 730-day battery lifespan
- Simple peel-and-stick adhesive install
Cons
- Requires separate HomeBase unit
The 3-Pack Entry Sensor by eufy delivers a dedicated multi-portal solution designed for homes that already feature an operating base station. Finished in gray, each battery-powered sensor utilizes self-adhesive mounting tape for quick, tool-free installation on any standard door or window frame. The listing highlights an average battery lifespan of 730 days, providing two full years of continuous perimeter monitoring. The compact profile ensures neat placement along residential entry points without interfering with daily opening and closing actions.
When forced entry is detected, each sensor prompts your connected HomeBase to sound a 100-decibel siren while instantly dispatching a push alert to your smartphone. This setup lets occupants quickly outfit multiple rooms, such as the front door, patio entrance, and a ground-floor casement window. In any head-to-head eufy door sensor comparison, this three-pack stands out as a focused hardware expansion for apartment renters and homeowners seeking multi-room coverage. However, it yields to newer hardware like the E20 model if your setup requires extended five-year battery endurance, dual-side alignment, or physical bypass toggles.
eufy Security Entry Sensor E20 One battery provides 800 days of monitoring
Check price on Amazon Our score: 8.0/10
Best for: Budget-minded perimeter expansion using renewed hardware
Pros
- 800-day battery life
- Includes mounting screws and magnet
- Peel-and-stick or screw installation
Cons
- Amazon Renewed condition
- Requires separate HomeBase
Best for: Standard single-portal entry monitoring
Pros
- Includes CR123A battery and screws
- Up to 800 days of monitoring
- Optional 24/7 monitoring service support
Cons
- Requires existing eufy HomeBase
Best for: Single portal expansion with long battery life
Pros
- 5-year battery on CR123A cell
- 656-foot open-air wireless range
- Dual-side detection flexibility
- Dedicated bypass button
Cons
- Requires existing compatible HomeBase
The eufy Security Entry Sensor E20 (model number T90E0) represents an upgraded single-point contact sensor powered by a single 3-volt CR123A battery that delivers up to five years of operational life. Measuring 2.88 by 1.54 by 0.85 inches, it features dual-side detection that allows matching magnets to be placed on either the left or right side of the main housing. This reversible alignment simplifies installation on narrow moldings, uneven door jambs, and sliding frames. Additionally, the unit boasts an open-air wireless transmission range of up to 656 feet (200 meters) back to the hub.
The E20 requires an existing eufy HomeBase updated to specific minimum firmware versions: HomeBase Mini (v4.0.5.2 or above), HomeBase 2 (v3.4.1.2 or above, post-2021), HomeBase 3 (v3.7.2.6 or above), or HomeBase Pro (v4.1.4.3 or above). Through eufy app version 6.0.00 or higher, opening a door can trigger connected cameras and lights automatically. A convenient bypass button lets users open a portal temporarily without sounding the HomeBase siren or disarming the broader system. Pairing well with high-traffic exterior portals or entry doors secured by an electronic lock operating on a eufy door lock battery, this individual sensor is ideal for expanding newer systems, but outfitting an entire house one sensor at a time is less convenient than buying a multi-pack.
eufy Security Entry Sensor
Check price on Amazon Our score: 8.8/10
The white eufy Security Entry Sensor is a slim magnetic contact sensor built to monitor opened and closed doors or windows. Powered by an included CR123A battery (with the listing noting one lithium-ion battery required), the unit provides up to 800 days of active monitoring, representing over two years of battery life. Measuring 1.1 inches long, 0.87 inches wide, and 2.91 inches high, its slender shape fits neatly along interior frames. The listing specifies a 7.5-watt rating, contact sensor technology, and an EU spare part availability duration of two years.
The package contains the entry sensor body, a contact magnet, three mounting screws, and an owner’s manual. Operating with a required eufy Security HomeBase, the sensor can trigger a 100-decibel siren on the hub and transmit instant smartphone notifications when entry is detected. The listing also notes support for an optional 24/7 professional monitoring service offering emergency dispatch for police, fire, and medical response. This unit suits users seeking single-portal perimeter security with screw-mounting capability alongside door hardware such as a eufy door lock with camera, but it gives way to the E20 if you want dual-side placement or a longer five-year battery span.
eufy Security 5-Piece Home Alarm Kit Install in minutes all by yourself
Check price on Amazon Our score: 9.8/10
Best for: Multi-layer room and entryway monitoring setups
Pros
- Includes entry sensors, motion sensor, and keypad
- No monthly service fees
- 1080p video resolution specification listed
Cons
- Listing lacks detailed sensor piece counts
The eufy Security 5-Piece Home Alarm Kit expands residential security beyond simple contact switches by combining entryway monitoring with interior spatial protection in a single system. Finished in white, this battery-powered setup connects wirelessly to smartphones and operates without recurring monthly fees. The kit includes entry sensors for doors and windows, an interior motion sensor, and a wall-mountable keypad for convenient physical arming and disarming. Specifications list a maximum wireless range of 30 feet, motion alert types, and a 1080p video capture resolution listing.
Installation is designed for DIY setup in minutes, with entry sensors adhering directly to portal frames and the keypad and motion sensor mounting via included wall brackets. This combination provides a two-layer barrier where perimeter contacts signal entryway breaches while the motion detector monitors interior passageways. This kit suits apartment renters and small office managers who want an immediate all-in-one foundation featuring physical keypad PIN control. However, because the listing does not specify the exact breakdown of how many entry sensors are included within the five-piece count, shoppers who need four or more dedicated door contacts should look toward dedicated multi-packs.
eufy Security Entry Sensor 2 years Battery Life: One battery provides 800 days of monitoring
Check price on Amazon Our score: 8.8/10
The renewed eufy Security Entry Sensor under the Amazon Renewed program offers an inspected, pre-owned hardware option for homeowners expanding an existing alarm setup. Powered by an included CR123A battery (listed as lithium-ion), this indoor-use sensor delivers 800 days—over two years—of continuous monitoring. The unit measures 1.5 inches long, 1.1 inches wide, and 0.87 inches high in white. The package includes the entry sensor, magnet, one CR123A battery, three mounting screws, an owner’s manual, and a Happy Card.
Connecting wirelessly to a required base station, the listing specifically identifies compatibility with the original HomeBase, HomeBase E, or HomeBase 2. When forced entry is detected, the sensor prompts the connected hub to sound a 100-decibel siren and sends a smartphone alert. Installation supports both peel-and-stick adhesive tape and mechanical screw mounting using the provided screws. This renewed unit suits budget-conscious users maintaining legacy eufy base stations who need an extra contact switch. However, it gives way to newer retail models like the E20 if you require HomeBase 3 integration, five-year battery endurance, or brand-new retail packaging.
Matching a Model to Your Setup
- Equipping a full home from scratch: The eufy Security HomeBase3 S380 Hub+4-Pack Entry supplies four perimeter sensors alongside a central hub with expandable local storage and AI recognition.
- Securing three key perimeter openings with an existing hub: The 3-Pack Entry Sensor by eufy delivers an efficient, self-adhesive trio of contact triggers offering two years of battery life.
- Monitoring a high-traffic back door with pet access: The eufy Security Entry Sensor E20 features a physical bypass button allowing temporary door openings without tripping alarms, backed by a 5-year battery.
- Securing a single window with permanent screw anchoring: The eufy Security Entry Sensor includes three mounting screws and a CR123A battery for mechanical attachment onto wooden frames.
- Covering both entryway doors and interior hallway movement: The eufy Security 5-Piece Home Alarm Kit bundles entry sensors with an interior motion sensor and a keypad for PIN-code arming.
- Expanding an older HomeBase or HomeBase 2 setup economically: The renewed eufy Security Entry Sensor delivers 800 days of battery life and verified legacy hub compatibility in an inspected package.
Before You Buy
Before purchasing any eufy door or window sensors, review your existing hub hardware and mounting surfaces carefully. Standalone models like the eufy Security Entry Sensor E20, the 3-Pack Entry Sensor by eufy, and the renewed eufy Security Entry Sensor strictly require a compatible eufy HomeBase to sound sirens and push smartphone notifications. Furthermore, newer models like the E20 mandate minimum firmware versions across HomeBase 2, HomeBase 3, HomeBase Mini, or HomeBase Pro, while older renewed listings cite compatibility limited to legacy hubs like the HomeBase E and HomeBase 2. The listings do not include standalone Wi-Fi connectivity for these contact sensors, meaning they cannot connect directly to home routers without an intermediary base station.
Physical installation requirements and component specifics also vary across listings. While the eufy Security Entry Sensor includes three mounting screws alongside adhesive options, other listings like the 3-Pack Entry Sensor specify only self-adhesive installation methods. For the eufy Security 5-Piece Home Alarm Kit, the product description notes that entry sensors, a keypad, and a motion sensor are included, but the listing does not specify the exact breakdown of how many individual door contacts are inside the five pieces. In addition, external hard drives for expanding the HomeBase S380 storage beyond its factory 16 GB are sold separately and not included in the retail box.
FAQ
Can eufy door sensors work without a HomeBase?
No, the listings state that eufy entry sensors require a compatible eufy HomeBase to function. The contact sensors communicate wirelessly with the central hub, which sounds the 100-decibel siren, executes automated camera triggers, and pushes alert notifications to your smartphone app.
How long does the battery last in eufy door and window sensors?
Battery life depends on the specific hardware model. Standard units such as the 3-Pack Entry Sensor by eufy and the eufy Security Entry Sensor provide between 730 and 800 days of monitoring, representing approximately two years of service. The newer eufy Security Entry Sensor E20 features an extended lifespan rated for up to five years on a single CR123A battery.
What does the bypass button on the eufy Entry Sensor E20 do?
The bypass button on the E20 model allows you to temporarily open a protected door or window without triggering the system alarm or sounding the HomeBase chime. Pressing the button deactivates that specific sensor for exit or entry while all other connected perimeter sensors remain armed and active.
Which eufy door sensor to buy for a standard home?
Deciding which eufy door sensor to buy depends on whether you currently own a hub. If you already have an active HomeBase, the 3-Pack Entry Sensor by eufy covers three primary perimeter portals cleanly. If you are starting fresh, the eufy Security HomeBase3 S380 Hub+4-Pack Entry provides four long-life sensors alongside a central hub with expandable local storage.
Can these contact units function as a eufy window sensor?
Yes, all listed eufy entry sensors are designed to function interchangeably as either a door contact or a eufy window sensor. Because they operate via magnetic contact separation, they can be mounted onto sliding windows, casement frames, or standard doors using the provided adhesive or screws.