If you own an Apple AirTag, Samsung Galaxy SmartTag, Tile, or Chipolo tracker, you have probably asked: what battery does it use — and what is the best replacement?
The short answer: most Bluetooth trackers run on CR2032 lithium coin cell batteries. But not all CR2032s are equal. Choosing the wrong one means shorter battery life, unreliable tracking, and more frequent replacements.
This guide covers every major Bluetooth tracker, the exact battery each one uses, how long it lasts, and why a high-performance lithium coin cell is the only replacement worth buying.
What Battery Do Bluetooth Trackers Use?
The vast majority of Bluetooth trackers use lithium coin cell batteries, with the CR2032 being the most common format. The “CR” designation indicates a lithium manganese dioxide chemistry — the same type used in car key fobs, medical devices, and digital watches. (For a full technical breakdown of the CR2032, see the Uniross CR2032 complete guide.)
| Tracker | Battery Type | Rated Battery Life By Manufacturer |
|---|---|---|
| Apple AirTag | CR2032 | ~1 year |
| Samsung Galaxy SmartTag2 | CR2032 | ~6–7 months |
| Samsung Galaxy SmartTag | CR2032 | ~6–7 months |
| Tile Pro | CR2032 | ~1 year |
| Tile Mate (2022+) | CR1632 | ~3 years |
| Chipolo ONE | CR2032 | ~2 years |
| Chipolo CARD | CR2025 | ~2 years |
The CR2032 dominates because it delivers the best balance of capacity, size, and availability in a 20mm diameter, 3.2mm height form factor.
Why Lithium Is the Only Chemistry That Works for Bluetooth Trackers
Bluetooth trackers are low-power but always-on devices. They broadcast a Bluetooth signal continuously sometimes every few seconds, even while sitting untouched in a bag for months. That demands a very specific type of power source.
Alkaline coin cells exist, but they are the wrong choice. Here is why lithium wins:
Stable Voltage Output
A CR2032 lithium cell holds a near-constant 3V throughout most of its discharge cycle. Alkaline cells sag in voltage as they deplete, causing trackers to report low battery prematurely or behave erratically.
Low Self-Discharge
A quality lithium coin cell loses less than 2% of its charge per year in storage. If your tracker sits unused for six months, a good CR2032 will still have close to full capacity when you need it.
Wide Temperature Range
Trackers end up in cars, bags left in the boot, and cold garages. Lithium coin cells operate reliably from −40°C to +60°C — alkaline chemistries lose significant capacity in cold conditions.
Long Shelf Life
Uniross CR2032HP lithium coin cells carry a 10-year shelf life, meaning a multipack bought today will still be fresh years from now — ideal for keeping spares in a drawer.
Apple AirTag Battery — Everything You Need to Know
The AirTag uses a single CR2032 battery. Apple rates it at approximately one year of battery life, though real-world life depends on:
- Precision Finding usage — the Ultra-Wideband (UWB) chip draws more power than passive Bluetooth pinging
- Ping frequency — frequent Find My requests drain the battery faster
- Temperature — cold environments reduce effective cell capacity
When the battery drops low, AirTag sends a notification to your iPhone. Replacement takes about 30 seconds: press and rotate the back cover counter-clockwise, swap the CR2032 (positive side up), and rotate the cover back.
Important note for AirTag users: Some CR2032 batteries with an anti-bitter coating can prevent proper electrical contact inside the AirTag. Uniross CR2032HP cells are coating-free and seat correctly every time.
Tile Tracker Battery — Which Model Uses Which Cell?
Tile uses different battery formats across its range:
- Tile Pro → CR2032
- Tile Mate (2022 and later) → CR1632
- Tile Slim → non-replaceable internal battery
If you own a Tile Pro, the same CR2032 recommendation applies. Tile Mate owners need a CR1632 a thinner 16mm coin cell available in the Uniross lithium coin cell range.
Samsung Galaxy SmartTag Battery Life
Both the Samsung Galaxy SmartTag and SmartTag2 use a CR2032. Samsung estimates 6–7 months per battery — shorter than AirTag because SmartTag uses UWB and more aggressive polling intervals. The SmartTag app sends a push notification when battery level drops low.
To replace: insert a coin into the battery cover slot, rotate counter-clockwise to open, swap the CR2032 positive side up, and rotate the cover closed.
CR2032 vs CR2025 vs CR2016 — What Is the Difference?
All three are 20mm diameter lithium coin cells. The trailing number indicates height in tenths of a millimetre. For a full side-by-side comparison beyond trackers, see the Uniross CR2032 battery guide.
| Model | Diameter | Height | Typical Capacity | Common Use |
|---|---|---|---|---|
| CR2032 | 20mm | 3.2mm | 220–240 mAh | AirTag, SmartTag, Tile Pro, Chipolo ONE |
| CR2025 | 20mm | 2.5mm | 150–170 mAh | Chipolo CARD, some older trackers |
| CR2016 | 20mm | 1.6mm | 75–90 mAh | Slim card trackers, key fobs |
Never substitute a thinner cell for a thicker one. A CR2025 in a CR2032 slot may not make reliable electrical contact, and a CR2016 will deplete far faster than expected.
Why Uniross CR2032HP Is the Best Replacement Battery for Bluetooth Trackers
Not all CR2032 batteries are built the same. The Uniross CR2032HP is engineered specifically for high-drain devices — which is exactly what a Bluetooth tracker is: a device that sends short, sharp bursts of power to its radio hundreds of times per day.
Specifications:
| Spec | Value |
|---|---|
| Nominal voltage | 3V |
| Capacity | 240 mAh |
| Annual self-discharge | ≤2% per year |
| Shelf life | 10 years |
| Operating temperature | −40°C to +60°C |
| Pack size | Blister of 5 |
The HP (High Performance) designation means the cell maintains stable voltage even under the pulsed current demands of a Bluetooth radio. That translates directly into longer effective battery life compared to standard coin cells — and fewer interruptions to your tracking.
Shop Uniross CR2032HP — Blister of 5 →
Need a different size for your tracker or key fob? Browse the full Uniross lithium coin cell battery range including CR2025, CR2016, and CR1632.
How to Know When Your Tracker Battery Needs Replacing
| Tracker | How It Alerts You |
|---|---|
| Apple AirTag | iPhone notification via Find My app |
| Samsung SmartTag | SmartThings app notification |
| Tile | Tile app notification + LED indicator |
| Chipolo | Chipolo app notification |
Most apps also show a battery percentage or indicator in the tracker’s detail screen. Check this periodically — especially before a trip.
Frequently Asked Questions
What is the best battery for an AirTag?
A CR2032 lithium coin cell. The Uniross CR2032HP offers 240 mAh capacity, stable 3V output, and a 10-year shelf life making it one of the best CR2032 replacements for AirTag. It is also coating-free, so it seats correctly without contact issues.
How long does an AirTag battery last?
Apple rates AirTag at approximately one year per CR2032. Real-world life is typically 8–14 months depending on how often Precision Finding is used and the ambient temperature.
Can I use any CR2032 in my AirTag?
Yes, but avoid CR2032 batteries with a bitter anti-taste coating — they can block proper electrical contact in AirTag. Uniross CR2032HP cells have no coating.
What battery does Samsung Galaxy SmartTag use?
Both the SmartTag and SmartTag2 use a CR2032 lithium coin cell.
Is CR2025 the same as CR2032?
No. Both are 20mm in diameter but the CR2025 is 2.5mm thick versus 3.2mm for the CR2032. They are not interchangeable — always use the size specified by your tracker’s manufacturer.
What battery does Tile use?
Tile Pro uses a CR2032. Tile Mate (2022+) uses a CR1632.
What type of battery does an AirTag use?
AirTag uses a CR2032 lithium coin cell a 3V, 20mm diameter button battery. It is one of the most widely available battery sizes in the world.
