I also use my JTV-59 & now 69S with DVI to my HD500, and prior to that, my X3L and XTL. I found it redundant to have the battery in there when I was powering it from the pedal, so I always have the battery out. I do keep it in my guitar case as a backup. I did need it once, as my VDI cable end apparently got bent or something -- don't remember stepping on it or anything, but one night at a gig about a year ago, one end just no longer fit in either the JTV or the POD X3L at the time, so I pulled out the battery and plugged into the X3L guitar in 1/4" jack for the night. It had been in my case for literally months, but still had a respectable charge on it to get me through. I quickly ordered anothe VDI cable, as I really missed the model switching with the patches -- even with the X3L.

When I got the nw 69S last week, I checked the battery that came with it and it was only showing one LED on the 69S, so I pulled out the charger and left it charging over night. It lit up all LED's the next day. Out of curiosity, I then pulled the battery out of my 59's guitar case and put it in the 69S to check the charge, and it lit up all LED's on the guitar. Again, it's been months since I last charged that battery. Li-Ion batterys hold thier charges for very long times, as opposed to Ni-Cad's, and they also do not have the "memory" issues of Ni-Cad's from too-frequent charging, and charging before their drained. With Ni-Cad's it's best to operate the battery until drained, with Li-Ion and gel-cells, if they go completely dead, they are usually done and you can't re-charge them. I know this for a fact on gel-cells, and am pretty sure it's that way on the Li-Ion's as well.

My advice if you run on the HD500, HDPro, X3L, or XTL power, pull the battery, charge it and store it in your guitar case for contingencies or use with a regular amp & 1/4" cable -- keep one of those handy as well, just in case. I'm glad I did that night....

Dave