So I've been bouncing around the amazing country of Germany for the past two weeks and I couldn't bare to leave my RYTM back in the States. I read every thread on here but had no luck finding a solid recommendation for a battery that didn't cost at least $100 ( or a lot more).
Well, I took a leap of faith on the following and couldn't be happier:
On a full charge, I,ve played over 3-4 hours and apparently only used about half of it's juice. On top of that, you can also power a 9V device (MicroGranny 2.4 for me) and a USB device (juicing my iPad) at the same time, although I didn't bring those along to test the batteries longevity running all three (also you will need to purchase another cable like the one included separately for the 9V).
This has been a game changer for me!
For the record, the first battery they sent was giving me some issues staying fully charged so they immediately sent me out a replacement which has been working perfectly.
The only bad side is I've nearly missed several of my stops on the Bahn because my eyes were glued to my black box