The Eelink BTT02 is an ultra-thin 2.4 mm BLE 6.0 temperature data logger built on the Nordic nRF54L10 SoC, with a built-in light sensor, ±0.2 °C accuracy across −20 °C to +60 °C, 100,000-reading on-device memory, broadcast range up to 500 m, IP67 sealing, a 1000 mAh battery rated up to 3 years, and PDF/CSV export through the BeaconCloud app and web for cold chain, pharmaceutical, warehouse and food logistics monitoring.
MODEL NO: BTT02 | ULTRA-THIN BLE TEMPERATURE LOGGER
BTT02 Ultra-thin BLE 6.0 Temperature Data Logger for Cold Chain & Logistics
The BTT02 is a 2.4 mm reusable BLE 6.0 temperature logger built on the Nordic nRF54L10 SoC. It records up to 100,000 readings on-device at ±0.2 °C, broadcasts to phones or gateways up to 500 m, and runs up to 3 years on a 1000 mAh cell.
- ±0.2 °C precision across −20 °C to +60 °C, plus a built-in light sensor
- BLE 6.0 broadcast up to 500 m — read by phone app or Eelink BLE gateways
- 100,000-reading on-device memory, exportable to PDF / CSV
- 1000 mAh battery, up to 3-year life · IP67 sealed · only 20 g
- Temperature, light & low-battery alarms · EELINK Beacon Protocol with OTA
Overview
The BTT02 packs precision temperature logging, light sensing, long-range BLE 6.0 broadcast and multi-year battery life into a sealed 2.4 mm tag built for cold chain and logistics.
Nordic nRF54L10 · BLE 6.0
Latest-gen Bluetooth LE SoC for efficient long-range broadcast and reliable connections.
±0.2 °C Precision
High-accuracy sensor measuring −20 °C to +60 °C for compliant cold chain logging.
Built-in Light Sensor
Detects ambient light from 0.01 to 655 lux — flags carton opening and exposure.
Triple Alarm Logic
Configurable high/low temperature, light-exposure and low-battery alerts.
100,000-Reading Memory
Stores up to 100K readings on-device, so data survives gateway or network gaps.
Up to 3-Year Battery
1000 mAh cell lasts up to 3 years in normal use, up to 1 year in cold conditions.
500 m BLE Range
Broadcasts up to 500 m in open air; adjustable −20 to +8 dBm power.
IP67 Waterproof
Fully sealed against dust and water for condensation-heavy reefer environments.
Only 2.4 mm Thin
Slim 20 g tag slips flat between cartons, pallets and product packaging.
EELINK Beacon Protocol
Standard Eelink broadcast format with firmware OTA for fleet-wide updates.
BeaconCloud App & Web
Configure parameters and review history on the BeaconCloud mobile app and web dashboard.
PDF / CSV Export
One-tap audit-ready reports with temperature curves and highlighted alarm events.
Cold Chain Data Pathways
One logger, three ways to get the data out. The BTT02 keeps a full local record while broadcasting live to phones or gateways — so a momentary network or device gap never loses a reading.
On-device Logging
Up to 100,000 readings are stored locally at your chosen interval. Data is retained even with no phone or gateway in range, then synced later.
Phone & App
Connect over BLE 6.0 with the BeaconCloud app to read live values, set alarm limits and interval, sync the clock, and export PDF / CSV on the spot.
Gateway to Cloud
An Eelink BLE gateway (TK417, TK418, TK419) captures broadcasts and forwards them to the Beacon Cloud server for 24/7 unattended monitoring and alerts.
Technical Specifications
Validated against the Eelink BTT02 user manual. Download the datasheet for the full reference.
| Category | Detail |
|---|---|
| General | |
| Product name | BTT02 — Ultra-thin BLE 6.0 Temperature Data Logger |
| Dimensions | 103.5(L) × 63(W) × 2.4(H) mm |
| Weight | 20 g |
| Ingress protection | IP67 (dust-tight, water-resistant) |
| Protocol | EELINK Beacon Protocol · Firmware OTA |
| Wireless | |
| Communication | Bluetooth LE 6.0 (broadcast + connection) |
| SoC | Nordic Semiconductor nRF54L10 |
| Broadcast power | −20 dBm to +8 dBm (adjustable) |
| Transmission range | Up to 500 m in open space |
| Compatible gateways | TK417 · TK418 · TK419 · TK419-3 · GPT46 |
| Sensors | |
| Temperature range | −20 °C to +60 °C |
| Temperature accuracy | ±0.2 °C |
| Light sensing range | 0.01 lux to 655 lux |
| Logging interval | Configurable (collection & storage interval) |
| Data & Alarms | |
| Local storage | Up to 100,000 readings (offline cache) |
| Alarms | Temperature high/low · light exposure · low battery |
| Data export | PDF & CSV (with curves and alarm flags) |
| App & Web | BeaconCloud app (iOS/Android) · Beacon Cloud web |
| Power | |
| Battery | 1000 mAh · 3 VDC |
| Battery life | Up to 3 years (normal) · up to 1 year (low-temperature) |
| Interface | |
| Button | 1× START (hold 3s on / hold 8s off) |
| Indicator | 1× red LED (status & activation) |
Last updated: June 2026 · Specifications subject to change without notice.
Components & Sensors
Everything the BTT02 needs is sealed inside the 2.4 mm enclosure — dual sensors, a single START button, a status LED and a multi-year battery.
Temperature Sensor
±0.2 °C accuracy across −20 °C to +60 °C.
Ambient Light Sensor
0.01–655 lux for carton-open and exposure detection.
Red LED Indicator
Visual feedback for activation, working and shutdown states.
START Button
Hold 3 s to power on, hold 8 s to power off.
1000 mAh Battery
Sealed cell rated up to a 3-year service life.
nRF54L10 BLE 6.0 SoC
Low-power Nordic chip driving broadcast and connectivity.
Applications
From reefer trucks to vaccine fridges, the BTT02 brings transparent, audit-ready temperature monitoring to every link in the cold chain.
Cold Chain Transport
Reefer trucks, sea containers and last-mile delivery. Continuous logging with threshold alarms for temperature compliance across the journey.
Pharmaceutical & Vaccine
GDP-aligned monitoring for vaccines, biologics and reagents. Audit-ready PDF/CSV records with full curve history for inspection.
Warehouse & Cold Storage
Place loggers across zones and shelves; Eelink gateways forward every reading to the cloud for 24/7 unattended room monitoring.
Food & Perishables Logistics
Farm-to-shelf visibility for produce, seafood, dairy and frozen goods. Light alarms also flag unexpected carton opening en route.
Frequently Asked Questions
Quick answers on BTT02 connectivity, sensors, deployment and data.
What wireless technology does the BTT02 use?
Bluetooth LE 6.0 on the Nordic nRF54L10 SoC. It both stores readings locally and broadcasts them, so data can be read by a phone or forwarded by a gateway to the cloud.
How far can the BTT02 broadcast?
Up to 500 m in open space. Broadcast power is adjustable from −20 dBm to +8 dBm to balance range against battery life for your environment.
Which gateways are compatible with the BTT02?
Eelink BLE-capable trackers including the TK417, TK418, TK419 and TK419-3, plus the GPT46. They capture BTT02 broadcasts and relay them to the Beacon Cloud server.
How accurate is the temperature measurement?
±0.2 °C across a −20 °C to +60 °C range, suitable for frozen, chilled and ambient cold chain monitoring.
What is the built-in light sensor for?
It detects ambient light from 0.01 to 655 lux. A light alarm flags when a sealed carton or container is opened unexpectedly, adding a tamper and exposure signal alongside temperature.
How do I activate the BTT02?
Press and hold the START button for 3 seconds; the red LED lights solid for 3 seconds then flashes for one minute to confirm boot. Hold 8 seconds to power off.
Is the BTT02 waterproof?
Yes. It carries an IP67 rating, sealing it against dust and water — important for condensation and wash-down inside refrigerated transport and storage.
How long does the battery last?
The 1000 mAh battery lasts up to 3 years in normal conditions and up to 1 year under sustained low-temperature operation, depending on logging and broadcast intervals.
How is data stored and exported?
Up to 100,000 readings are cached on-device. Through the BeaconCloud app or Beacon Cloud web platform you can view temperature curves and export PDF or CSV files with alarm events highlighted.
What alarms does the BTT02 support?
High and low temperature thresholds, light exposure, and low battery. Alarm limits and intervals are configured over BLE in the BeaconCloud app.
How does the BTT02 compare to single-use USB temperature loggers?
Single-use USB loggers are read once at destination by plugging into a PC. The BTT02 is reusable, broadcasts live over BLE for in-transit visibility, retains 100,000 readings, adds a light alarm, and runs up to 3 years — lowering cost per shipment over time.
How does it compare to other reusable BLE temperature loggers?
The BTT02 pairs an ultra-thin 2.4 mm form factor and IP67 sealing with a built-in light sensor and the EELINK Beacon Protocol, so it slots directly into Eelink gateways and the Beacon Cloud platform for an end-to-end OEM/ODM cold chain solution.
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