How is this 3 pad connector called? I'm trying to build something similar into a product but can't seem to find anything similar.
What exactly are you trying to achieve?
If you are making a product that needs a battery but you are not prepared to tool up a custom design then I would strongly suggest that you look at the possibility to source an existing 3rd party battery and concentrate on the other aspects of your product. Adapt your product around that battery selected.
Make sure to select something that was or is widely used in the market place. For example you would do well to select a battery style from something like a Panasonic point and shoot camera that has several alternate sources for its batteries and sold world wide as opposed to some special battery pack made for a portable baby monitor.