Uniden BT-800 Cordless Phone Replacement Battery 3.6V 1300mAh
This product ships directly from our Manufacturer’s Warehouse and is usually delivered within 5 – 8 business days to your doorstep.
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Uniden BT-800 Cordless Phone Replacement Battery 3.6V 1300mAh - is backordered and will ship as soon as it is back in stock.
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Battery Care Tips
Battery Care Tips
🔹 Getting Started
Charge your new battery fully before you use it for the first time. Over the next few charge cycles, run your device down to around 20% before you recharge—this helps the battery perform its best. After that, charge whenever you need to.
🔹 Keep It Healthy
Avoid letting your battery completely drain or staying plugged in constantly. Both extremes wear it out faster. Store the battery in a cool, dry place when you're not using it, since heat damages batteries quickly.
Delivery and Shipping
Delivery and Shipping
🔹 Most orders ship the next day, and we use FedEx, UPS, Purolator and other carriers to get them to you. Lithium batteries have to ship by ground only, not air or USPS. Make sure your address is right before you order, because if we have to send it back, you pay for shipping again.
Disclaimer
Disclaimer
⚠️ Disclaimer: All product names, trademarks, and registered trademarks belong to their respective owners.
🔹 We use these names, brands, or model numbers only for identification and compatibility purposes.
Uniden BT-800 Cordless Phone Replacement Battery 3.6V 1300mAh - is backordered and will ship as soon as it is back in stock.
Voltage
3.6V
Amp
1300mAh
Uniden 24-148 / AE255 Series — 3.6V Ni-MH Replacement Battery (BT-800 / BT-905)
This is a 3.6V, 1300mAh Ni-MH rechargeable battery for Uniden cordless phone handsets, including the 24-148, AE255, BBTY0300001, and BBTY0444001 among many others. It replaces OEM part numbers BT-800 and BT-905. When the original pack stops holding a charge, this battery restores normal handset operation without replacing the whole phone system.
- Broad handset compatibility: These Uniden models share the same 3.6V NiMH cell configuration, connector pinout, and charge-acceptance voltage range — so one battery pack covers over 160 handset variants without modification.
- Bench tested on actual hardware: We cycled this pack through charge and discharge on a Uniden handset cradle. The BMS accepted charge correctly at the base station voltage and held stable output across the RF transmit load without dropping below the handset's low-battery cutoff threshold.
- First-charge protocol for NiMH handsets: After installing, seat the handset in the base and leave it for a full 16 hours before use. NiMH cordless phone batteries do not reach rated capacity on a short first charge — skipping this step is the most common reason a new battery appears weak out of the box.
Range dropping after a battery swap on Uniden cordless handsets
NiMH cells that haven't been conditioned yet show a lower resting voltage than a fully cycled pack. When the handset's RF transmitter pulls current during a call, that low voltage sags further — and the handset responds by reducing transmit power to stay within operating limits. The result looks like a range problem, but it's actually a voltage problem. Run three to five full charge-and-discharge cycles through the base station and the transmit power will stabilise at its normal level.
Base station shows no charge light or error after installing a new battery
NiMH batteries discharged below approximately 3.0V during storage can fall outside the voltage window the base station uses to detect a valid battery. The charger circuit sees a voltage it doesn't recognise and either shows an error or does nothing. To recover, leave the handset seated in the base undisturbed for at least 30 minutes — most Uniden base stations apply a trickle current that slowly raises cell voltage until the charge circuit takes over. If the charge light comes on after that window, the pack is recovering normally.
Compatible Models
Replaces Part Numbers
Technical Specifications
Product Highlights
- Brand: Uniden
- Manufacturer: CS
- Series: Standard
- Color: Black
- Product Type: Ni-MH
- Battery Type: Ni-MH
- Warranty: 12 Months
- Bulk Orders: sales@batteryweb.com
Frequently Asked Questions
My new Uniden battery talk time is much shorter than the old one — is it defective?
It's almost certainly not defective — it's unconditioned. NiMH cells ship partially discharged and don't reach rated capacity until they've been through three to five full charge-and-discharge cycles in the base station. Run the handset down until it signals low battery, then seat it for a full 16-hour charge, and repeat that cycle at least three times. Talk time will increase noticeably with each cycle.
The handset lost its pairing with the base after I swapped the battery — how do I fix it?
Some Uniden DECT handsets store pairing data in volatile memory that resets when power is fully removed during a battery swap. The fix is to re-register the handset manually. On most Uniden models, press and hold the Page or Find button on the base station for five seconds, then follow the handset's on-screen registration prompt — the exact sequence is in the handset's setup guide under "registering a handset."
The battery drains completely overnight even when the handset is sitting in the base — what's causing it?
This points to the handset not making proper contact with the charging cradle rather than a battery fault. Check that the handset is fully seated — a slight tilt or debris on the charge contacts is enough to break the circuit while the handset's standby draw continues. Clean the gold contacts on both the handset and the base with a dry cloth, reseat the handset firmly, and confirm the charge indicator light activates within 30 seconds of placing it in the cradle.
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