Motorola TalkAbout AA Battery Kit for 280 & T289 Series

Rating:
Summary: Using AA NiMH with this AA Alkaline battery kit
Review: I just finished the my own drain test with 3 x Maha 1550mAh AA NiMH batteries in TalkAbout TA280. The results are quite interesting.

TB is smart enough to tell it is being powered by original Motorola proprietary NiMH rechargeable (3.6V, have 3 contact points) or Alkaline AA adaptor kit (4.5V, have only 2 contact points).

I put 3 FULLY-CHARGED 1.2V NiMH into the Alkaline AA adaptor and started up the FRSs. The battery indicator showed only 2 (out of 3) bars. It was working without strange behavior though. I left them on and it ran out of power 30 hours later !! The battery indicator stayed at 2 for more than 18 hours and dropped to 1 for the rest. I used it occasionally (just to see it was still alive).

I think when you install the AA Alkaline battery kit, the TB is expecting 4.5V (= 3 x 1.5V). However, 3 x AA NiMH 1.2V batteries yielded only 3.6V (< 4.5V) and this attributes to the 2 (out of 3). On the other hand, AA NiMH can deliver stable 1.2V for 80% of the discharge cycle which attributes the 'long-standing' 2 and 1. Whereas Alkaline poses a steeper discharge curve than NiMH.

I will try them again to test how the 'real-life' performance (duration, range) will look like using NiMH in Alkaline adaptor.

Rating:
Summary: Using AA NiMH with this AA Alkaline battery kit ... part II
Review: Just came back from Birch Run, Michigan (the real-life test site of my pair of TA280s AA model).

Some 150 outlet stores scattered around the whole block. To go from one section to another, driving is often required. A pretty ideal place to use FRSs, especially your spouse/kids have very different preferences of stores to visit.

I fully-charged a set of Maha 1550mAh NiMH AA batteries for each unit and started them off at around 10:00am. With frequent conversation, it lasted thru the day until I turned them off at around 10:00pm with 1 bar (out of 3) left at the battery indicator.

I don't know the capacity of the proprietary Motorola NiMH battery for TA28x but Motorola claims 11 hours of 'normal' usage (5%/5%/90%). My 1550mAh NiMH AA setup beats this handily. Also, just imagine how much $$$ you are going to save from those disposable alkalines.

I am quite pleased about the performance of my batteries as well as the FRSs so far. Highly recommended.