So I got this in the mail today. Thanks AngryRooster.I have one of those AA battery packs for the UV-5R. I never really use it. It's like this one except it's not by Btech. I looked in my order history and it seems the seller I got it from back in 2014 is gone now.
https://smile.amazon.com/BTECH-BaoF...06926&sr=8-3&keywords=baofeng+aa+battery+pack
If anyone has one of these EX model radios and wants to try it out let me know, you can have it. I haven't used it in years and don't really plan to.
ETA: IIRC I had to do some mild filing of the top to get it to fit without popping off the radio like Camerymonkey's did above. Once it was together and fitted to the radio it seemed to stay attached well enough. They are cheaply made and probably not checked for fit very well at the factory.
I do have one of the extended 3800 batteries and it fits much better. There was minor filing but it snaps right into place and holds tight. It fills the hand well, great for playing with satellites.
It did not fit the newer version UV-5R EX model. The hook on the latch is much fatter then the new version and also those ears on top won’t let it slide in ether. You would have to remove the ears completely and also file the back of the hook so it could insert into the radio latch. So this means the older version batteries won’t work out of the package. It may work if you highly modify it. I have not found a source for extra UV-5R EX batteries. The group buy may want to switch to the older version.