I've had the Tascam DR-60D for about 4 years now (it's now been replaced with the mk II) and I barely bought a battery pack to power it via USB. I filmed a conference where I needed to record audio for about 6-7 hours straight and I knew AA batteries weren't gonna survive. The DR-60D eats through AA batteries. I mean really. I've gone through so many batteries. I should have bought this external battery so long ago. I looked around online to see what other people were doing and I saw that some people were attaching them to their tripods and external mounts. I think I've found something more convenient.
I found myself reading about gear all the time but never posting anything I've learned, so I've decided to make an effort to show the solutions that I've come up with.
Here's what I bought:
For about $30, you won't need to buy batteries for the DR-60D again! I attached two velcro strips on the outside of the DR-60D's battery door so that I can attach the battery right onto the recorder. Make sure you use two. Only one strip wasn't enough to hold the battery pack securely.
From there, you use a USB cable to connect the battery pack to the DR-60D and that's it! You can also put AA batteries in the DR-60D as backup. If the external battery dies or gets unplugged, the DR-60D will automatically pull power from the batteries without shutting off.
I haven't tested how long the DR-60D can record with the external battery, but I did record audio from the conference for about 6 hours and it seemed like I only used about 30% of external battery. However, your mileage may vary. This is also my go to for run and gun setups. It's a bit crazy with the wires on both sides, but it's still pretty compact! Usually I'll attach a quick release plate on the bottom of the Tascam that way I can mount it on a tripod quickly if I need to.