Don't even bother with the original manufacturer. Even if by some chance
they had the battery pack you need, odds on it would be the same age as the
radio and the batteries would only hold a twenty minute charge. I have seen
this happen a number of times when we had to replace portable pc or radio
batteries. even from first class companies like Gateway and Raytheon.
Think about it, when you build or commission a device to be built you order
the spares at the same time and put them on the shelf until someone orders
them.