1. Introduction
Thank you for choosing the Kastar BT-1025 Ni-MH rechargeable battery. This battery is designed to provide reliable power for a wide range of Uniden cordless telephones. This manual will guide you through the proper installation, initial charging, operation, and maintenance to ensure optimal performance and longevity of your battery.

This image displays a pack of six Kastar BT-1025 Ni-MH rechargeable batteries, ready for use.
2. Safety Information
Please read and follow these safety guidelines carefully to prevent damage to the battery or your device, and to ensure personal safety:
- Do not disassemble, crush, puncture, or short-circuit the battery.
- Do not expose the battery to high temperatures or direct sunlight.
- Do not dispose of the battery in fire or water.
- Use only the specified charger for your cordless phone.
- Keep batteries out of reach of children.
- If the battery leaks, avoid contact with skin and eyes. Rinse thoroughly with water and seek medical attention if irritation persists.

This image shows the Kastar BT-1025 battery. A label on the battery pack advises to charge the battery for 15 to 20 hours before connecting it to a phone line.
3. Setup and Installation
Follow these steps to install and prepare your new Kastar BT-1025 battery:
- Unpack the Battery: Carefully remove the battery from its packaging.
- Locate Battery Compartment: Refer to your cordless phone's user manual to locate and open the battery compartment, typically on the back of the handset.
- Connect the Battery: Align the battery connector with the corresponding port inside the phone's battery compartment. Gently push until it clicks into place. Ensure the polarity is correct.

A detailed view of the battery's 2-pin connector, which connects to the cordless phone's battery compartment.
- Close Compartment: Securely close the battery compartment cover.
- Initial Charge: Before connecting your phone to a phone line or using it for the first time, place the handset on its charging base and charge the battery continuously for 15 to 20 hours. This initial charge is crucial for conditioning the battery and achieving its full capacity.
4. Operating Instructions
Once the initial charge is complete, your battery is ready for normal use.
- Regular Charging: For daily use, return the handset to its charging base when not in use. This helps maintain the battery's charge level.
- Battery Indicator: Monitor your phone's battery indicator. Recharge the battery when the indicator shows low power to prevent interruptions during calls.
- Full Discharge (Occasional): To optimize battery life, it is recommended to allow the battery to fully discharge occasionally (e.g., once every few months) before performing a full recharge.
5. Maintenance
Proper maintenance can significantly extend the life of your Kastar BT-1025 battery:
- Avoid Extreme Temperatures: Do not expose the battery or phone to extreme heat or cold, as this can degrade battery performance and lifespan.
- Clean Contacts: Periodically clean the metal charging contacts on both the handset and the charging base with a dry cloth to ensure a good connection.
- Storage: If storing the battery for an extended period, charge it to about 50% capacity and store it in a cool, dry place. Recharge it every 3-6 months to prevent deep discharge.
- Lifespan: The Kastar BT-1025 battery is designed for up to 1200 charge cycles, offering long-term reliability.
6. Troubleshooting
If you experience issues with your battery, consider the following:
- Battery Not Charging:
- Ensure the handset is correctly seated on the charging base.
- Verify the charging base is properly connected to a power outlet.
- Clean the charging contacts on both the handset and base.
- Confirm the initial 15-20 hour charge was completed.
- Short Battery Life:
- Ensure the battery is fully charged before use.
- The battery may be nearing the end of its lifespan (rated for up to 1200 cycles).
- Environmental factors (extreme temperatures) can affect battery performance.
- Phone Not Powering On:
- Check if the battery is correctly installed and connected.
- Ensure the battery has sufficient charge.
7. Specifications
| Battery Type | Ni-MH (Nickel-Metal Hydride) |
| Voltage | 2.4V |
| Capacity | 400mAh |
| Dimensions | 44.5 x 20.5 x 10.2mm (1.75" x 0.8" x 0.4") |
| Reusability | Rechargeable (up to 1200 cycles) |
| Environmental | Eco-friendly cell, does not contain Hg/Cd/Pb |
| Model Number | MH-6B-BT1025-E |
8. Compatibility
The Kastar BT-1025 battery is compatible with numerous Uniden cordless phone models, including but not limited to:
- Uniden BT-1025, BT-1021, BT-1019, BT-1016, BT-1008
- Uniden BBTG0645001, BBTG0734001, BBTG0847001, 65AAAH2BMS
- Uniden D1361, D1361BK, D1364, D1364-2, D1364-3, D1364BK
- Uniden D1384, D1384BK, D1384-2, D1384-2BK, D1384-3, D1384-4, D1384-4BK, D1384-5, D1384-6
- Uniden D1483BK, D1483W
- Uniden D1660, D1660-2, D1660-2T, D1660-3, D1660-4
- Uniden D1680, D1680-2, D1680-3, D1680-3T, D1680-3X, D1680-4, D1680-8
- Uniden D1685, D1685-2, D1685-3, D1685-4, D1685-5
- Uniden D1688, D1688-2, D1688-2T, D1688-3, D1688-4, D1688-5
- Uniden D1760, D1760-2, D1760-2W, D1760-3
- Uniden D1780, D1780-BT, D1780-2BT, D1780-2W, D1780-3, D1780-3BT, D1780-4
- Uniden D1785, D1785-2, D1785-3, D1785-4, D1785-5, D1785-6, D1785-7, D1785-8, D1785-9, D1785-10, D1785-11, D1785-12, D1785-2T, D1785-3T
- Uniden D1788, D1788-2, D1788-3, D1788-4, D1788-5, D1788-6, D1788-7, D1788-8, D1788-9, D1788-10, D1788-11, D1788-12
- Uniden D2997, D2997-2, D2997-3, D2997-4, D2997-5, D2997-6
- Uniden D2998, D2998-2, D2998-3, D2998-4, D2998-5, D2998-6
- Uniden D3097, D3097-2, D3097-3, D3097-4, D3097-5, D3097-6, D3097-7, D3097-8, D3097-9, D3097-10, D3097-11, D3097-12, D3097S
- Uniden D3098, D3098S
- Uniden D3500, D3580-2, D3580-3, D3588, D3588-2, D3588-3
- Uniden DCX160, DCX170, DCX170BT, DCX170T, DCX170W, DCX200, DCX200-SLV, DCX200WHT, DCX210, DCX291, DCX309, DCX350
- Uniden DECT 1588, DECT 2060, DECT 2060-2, DECT 2080, DECT 2080-2, DECT 2080-5
- Uniden DECT1363BK, DECT1560, DECT1580, DECT1588, DECT1588-5
- Uniden DECT2060, DECT2060-2, DECT2080, DECT2080-2, DECT2080-2W, DECT2080-3, DECT2080-4, DECT2080-5
- Uniden DECT2085, DECT2085-2, DECT2085-2W, DECT2085-3, DECT2085-4, DECT2085-4WX, DECT2085-5
- Uniden DECT2088, DECT2088-2
- Uniden DECT2180, DECT2180-2, DECT2180-3, DECT2180-4
- Uniden DECT2185, DECT2185-2, DECT2185-3
- Uniden DECT2188, DECT2188-2, DECT2188-3, DECT2188-4, DECT2188-5
- Uniden DECT2662, DECT2662-2
- Uniden DECT2882, DECT2882-2, DECT2882-3
- Uniden DECT2888, DECT2888-3
- Uniden 1780-2, DWX207, WX12077, WXI2077
- Radio Shack 23-596, 23596, 23-931, 23931, 43-221, 43221, 43-223, 43223, 43-269, 43269, BT1008, DCX200
- Southwestern Bell BT1008, DCX200, DECT 2060, DECT 2080
- Energizer ER-P152
- Empire CPH-515B
- Sanyo CAS-D6325
- Dantona BATT-1008
- Interstate Batteries ATEL0031, TEL0031
9. Support
For further assistance or inquiries regarding your Kastar BT-1025 battery, please contact Kastar customer support. Your feedback is valuable for product improvement.

The Kastar product box, featuring a message that invites customers to share their feedback for product improvement.