Originally Posted by kopfan
correct me if i am wrong.
a proper battery replacement will need to be a 12v Sealed Lead Acid, size: 7.1" x 3" x 6.5" with flat terminal connectors. Higher AH (capacity) will give you longer run.
Even if you find the size and type of battery you want but with different connectors than what your machine needs you can sometimes buy adapters to make that battery work with your machine. I did this and saved about $15 by buying the battery I needed but with the wrong connectors for my SP and separately buying the adapters to make it work. I found the adapters for $.56 each with free shipping too. You just have to wear out google and wade though a lot of battery sites but deals are out there.