Here's the thread about using more than 5v:
http://taperssection.com/index.php?topic=125404.0I suspect that 7 is too much, but 6 might be fine.
None of this has to do with the internal, though. Just an external.
If a steady 6v did not overheat after 6 hours or so, I'd say that is the key to keeping the internal "charging" while in the field.
Again, the important part about that is that once the external is done, you are running down your internal, and the only has so many charges before its unreliable.
I am definitely keen on watching igene go on this search for a better internal.
One that could run the thing for 4-5 hours while pulling DSD is really all you would need.
But again, that battery would eventually lose its charge and probably fast when it happens.
One day you'd have 4 hours of record time and the next 2, etc...
That's how my first one went.
Now I feel its important to not actually fully charge > discharge all the time to keep the life in them for when you need it.
(like the spontaneous jam session in the bar after the show when your gear is all stowed away but your MR1 isn't)
But if we could land on a battery that we could easily replace when the time comes (for less than the cost of a new deck) then I wouldn't even think twice. But I'd probably still want an external in a pocket for when the 3 hour mark arrives.
I'm pretty happy with the internal drive, and I can understand the desire to eliminate the moving parts by replacing the HD, but until that can guarantee the error-free writes that the current HD has, then that seems to risky for the primary deck.
BTW, they are now completely out of production, so maybe Korg has some batteries they'd let go in bulk somewhere.
Its not like them to ever release release anything that might help hobyists tinker with their products, but I would love to have a gross of those batteries and be able to pop them out and put new ones in.
In fact, that would be the real way to upgrade this deck:
Remove the battery altogether and cut a slot in the side which would take a pre-charged lithium that fit into it like a memory card.
I realize it sounds crazy, but looking at the size of the battery, it wouldn't be too troublesome if it had some extra hardware on it-- if it had a connection grid that would allow it to snap in and hold, which could be built in the space the battery used to take, then it stuck out the side a little, that wouldn't be too bad. (I guess it would have to be the bottom, though)
You could build a unit to hold 4 batteries and charge them, then you'd have a handful of 2+ hour batteries in your pocket at the show & you could just shut down, pop one out and pop a new one in.
Yes, I realize that's all crazy, but then that's how all of this looked when i started reading it.
Picture something like this:
http://eshop.macsales.com/item/Newer%20Technology/BATCAPMB13/That would have all your batteries in it.