Motorola Talkabout T82 Extreme Wont Charge

Why wont the T82 Extreme charge standard NiMh batteries?

The Motorola Talkabout (not TLKR) T82 Extreme has a micro USB port which you can use to charge the 700mAh battery pack. I put some standard NiMh cells and was puzzled why it would not charge them.

I looked at pictures of the rechargeable battery pack, to see if there was any clues as to how the radio detects it has a rechargeable pack in it

There was nothing obvious, and I pondered the problem for a few moments, then it came to me. The radio detects voltage across the middle cell, which is not connected when the rechargable pack is used.

So, to get the radio to charge standard NiMh cells we just need to disconnect one end of the middle cell from its contact in the radio. However, that connection is also linked to the adjacent cell and thats how the cells are connected together. We need to electrically link the 2 cells together, then isolate them from the radio contacts.

I have tested this and it works, but have not actually done the job yet. One thought is to use a thin piece of metal from a drinks can or something, stick some insulating tape on one side and wedge it in. This should create a good solution, without needing to do any permanant modifications to either the radio or battery pack.

EDIT 27/06/2020: I have now done the job. I used some aluminium foil tape (as used to seal air conditioning ducts and stuff), I left the backing paper on one side and cut it to fit, placed it in the radio (paper side facing the radio contacts) and carefully re-installed the NiMh cells. It works perfectly and with the tape/paper being so thin, it doesn't affect the radio detrementally in any way.

An elegant and effective solution, though the alu-foil tape is quite expensive. Thankfully I had some here from a previous repair to my air-con ducting.

The Motorola Talkabout T82 Extreme is a 16 channel radio, but when you receive it you may be disapointed to find it only has 8 channels.

The other 8 channels need to be unlocked by the user if it is legal in their region. Its a way that Motorola can ship the exact same radio to all countries and dont have to make different radios for each region.

To unlock the full 16 channels; turn the radio on, press the menu button once so that the channel number flashes, then immediatly press and hold both the + and - buttons, after about a second the radio will display 16 CH. That's it, your radio is in 16 channel mode. However, be sure you want the radio in 16 ch mode, because at the time of writing this, there is no known way to revert the radio back to 8 channel mode

Turn the radio off, Press and hold both the Menu button and the Lock button, then turn the radio on, then once you have noted the firmware version release the buttons. The radio should display a big U on the top line (U = V for version) and then a number on the bottom line such as 012.