# Replacing the battery

Efento BLE loggers are powered by a single **AA 3.6 V lithium battery (type ER14505)**. Battery life depends on the logger model and configuration, but when the battery becomes depleted, it must be replaced to ensure continuous operation and accurate measurements.

## General notes

* Always use the recommended battery type: **ER14505, 3.6 V lithium, 2700 mAh**.
* Do **not** use rechargeable batteries or standard alkaline AA batteries.
* Dispose of used batteries according to local regulations.
* Measurements stored in the logger's internal memory are **retained during battery replacement** and will not be lost.

## IP30 enclosure

1. **Remove the back cover**\
   Use a cruciform screwdriver (PZ1 / PH1) to remove all screws from the housing.
2. **Replace the battery**
   1. Pull the old battery out of the holder.
   2. Insert the new battery, ensuring correct polarity (+/–).
3. **Reattach the back cover**\
   Insert and tighten all screws evenly.

The device will automatically restart and resume operation using the existing configuration.

## IP67 enclosure

IP67 loggers provide waterproof and dustproof protection. Because the enclosure is fully sealed, extra care is required when opening and closing the device to maintain its environmental rating.

1. **Open the enclosure**
   * Use a cruciform screwdriver (PZ1 / PH1) to remove all screws from the housing.
   * Lift the cover carefully to avoid damaging the sealing gasket.
2. **Check the gasket**\
   Inspect the rubber seal for dirt, wear, or deformation. Clean if necessary to ensure proper sealing.
3. **Replace the battery**
   * Remove the old battery from the holder.
   * Insert the new battery, ensuring correct polarity.
4. **Close the enclosure**
   * Align the cover so the gasket sits evenly.
   * Insert and tighten all screws evenly.
   * Make sure every screw is fully tightened - **insufficiently tightened screws may compromise waterproofness and damage the electronics**.

The logger will power on automatically once the battery is inserted.


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