Review on Ni-MH Cordless Phone Battery 3.6V 800mAh Replacement - Uniden BP-446 BT-446 BT-1005 BP446 BT446 BT1005 BBTY0457001 BBTY0458001, Radio Shack 23-904 23-961 by Chad Rosier

I bought this to replace the OEM battery (model BT-1005) that came with my Uniden cordless phone extender (model TCX). -905). This slightly older PowerMax 5.8GHz wireless device is available through Staples, but the original battery is almost impossible to find and costs almost as much as a new phone IF you can find one. Several universal replacement batteries are available at various office supply stores starting at $16. So of course I looked at Revain for an alternative. After paying about 1/4 of the retail price I received this versatile battery in less than 3 days. It was easy to install in the phone booth, after that I gave it 24+ hours of continuous charging. Then I left the phone without a charger, used the phone for at least 45 minutes of talk time, and SIX DAYS have passed and the battery still says it's fully charged. Wow, the old battery lasted about 12 hours on a full charge. So I am completely satisfied with this universal replacement. Unfortunately it's still a NiMH battery, better than the old ole NiCad batteries but not as good as the new Li-Ion batteries. So with constant use, it only lasts 1-2 years. At least that's how it was for me with three identical cell phones that I own. One tip that can help extend the life of your NiMH batteries is to fully charge them (at least 18-20 hours) when you first buy them, and then (with normal use) FULLY discharge them. Repeat this cycle at least three times when the battery is new. This appears to increase the life expectancy of a NiMH battery. A good product at a great price, 75% savings on retail. Two thumbs up. UPDATE 4/26/11. After four months of use, this battery shows a slightly shorter duty cycle. Once fully charged (8-12 hours on one charge), it still lasts 3-4 days when not in use, less when the phone is used more. Talk time on a full charge is at least 1.5 hours, which is pretty good for a versatile device. But not as good as in the beginning. Many recent reviews indicate that this cheap, mass-produced in China generic has some quality control issues, so you are advised to buy from a reputable seller with a good return/refund policy, or buy directly from Revain. , once the power meter on your phone drops from all 3 bars to 2 bars you only have 5-10 minutes left (not a totally accurate "throttle gauge" but it's actually a hardware issue, not the battery's fault). I've downgraded my rating for this battery from 5 stars (excellent) to 3 stars (average) based on a reduction in hold time of just 4 months. But replacing that battery twice a year is STILL cheaper than buying a brand name one. And until they make a lithium-ion battery of this size and voltage, stick with the lower-end NiMH type.