I said awhile about my battery problem, so thought I'd show you what I did today 
My old korg i5s..
The problem was, the original battery was electronic soldered on (i think)
Which meant it didn't come with a battery holder. so changing the battery wasn't something korg must have thought about.
This was the problem
This was the solution, to fit a new holder.
They're a pound on ebay.
So, a bit of de soldering later..
If you look at the first picture, you'll see that the live is held down by 2 points.
because the new holder only has one, I jumped it with a piece of wire.
The new battery holder not only looks a lot more better, but also allows the battery to be replaced with ease.
Now when I turn it on. I no longer get the internal battery low message.
My old korg i5s..
The problem was, the original battery was electronic soldered on (i think)
Which meant it didn't come with a battery holder. so changing the battery wasn't something korg must have thought about.
This was the problem
This was the solution, to fit a new holder.
They're a pound on ebay.
So, a bit of de soldering later..
If you look at the first picture, you'll see that the live is held down by 2 points.
because the new holder only has one, I jumped it with a piece of wire.
The new battery holder not only looks a lot more better, but also allows the battery to be replaced with ease.
Now when I turn it on. I no longer get the internal battery low message.