BlueSwordM
(BlueSwordM)
2
Ok first off, please separate into paragraphs. It makes it much easier to read :+1:
Also, don’t delete topics like this! They are very helpful for people who search on the web and want to find answers 
Now, the battery you spoke about are 1,2Vx3 cells in series resulting in a 3,6V battery pack.
So, what you would need to do is just put 3xNiMH rechargeable AAs in series. At 2000mAh total capacity, you would be getting 3 times the total energy, and it would actually be a bit more powerful and run a lot longer.
Also, could you please take a picture of the battery pack? That would help a lot!