# Battery estimates and replacement dates

> For the complete documentation index, see [llms.txt](https://docs.oriondata.io/llms.txt)

How replacement dates, battery types and device models affect displayed battery estimates.

## Overview

The **Battery Reset** feature in the Orion database allows users to track battery replacements more accurately. This enhancement introduces a **“Last Battery Change”** date field in the **Device Configuration** page, ensuring better monitoring of battery life and performance.

## Feature Details

### 1. Last Battery Change Date

- A new field, **“Last Battery Change”**, is added to the **Device Configuration** page.
- Users should update this field every time a device’s battery is replaced.
- This date is used to start counting transmits for **non-rechargeable** batteries.

### 2. Battery Type Identification

All devices in Orion are considered **rechargeable**, except when:

- **Device Type** is set to **Tilt**
- **Battery Sensor Type** is set to **Non-rechargeable Battery (NR)**

For non-rechargeable devices, battery life is estimated based on **2500 transmits per battery lifetime**.

### 3. Battery % Calculation Logic

#### Non-Rechargeable Batteries (NR)

- **EWS Tiltmeter** → Always follows **NR (2500 transmits)** calculation.

- **Other Devices**(EWS Switch MKII, DVWT, EWS Solar Mount MKII, MKII VWT, EMT):

  - If **offline for 5+ days** → Battery % = **0%**
  - If **Battery Sensor Type = NR** → Uses **NR calculation (2500 transmits)**
  - Otherwise → Uses **3.1V calculation**

- **All Other Devices** use the **8.2V calculation**.

## Frequently Asked Questions (FAQs)

### 1. What happens if I don’t update the “Last Battery Change” date?

If the date is not updated, Orion may not track the correct battery usage, leading to inaccurate battery life estimates for non-rechargeable devices.

### 2. Does this change impact rechargeable devices?

No, the battery percentage for rechargeable devices continues to be calculated using the battery voltage curve.