The only off the shelf ones would be to take one off a charger.
Tho they can be make real easy with some blades from a regular 110ac plug soldered on to some wire and a way to hold them such as a small pcs of circute board and some super glue. If you dont mind some thing thats ugly and frankenstied looking.
What i did for a plug was to use the blades from and old 110ac plug and then made a body for it that was shaped so it can only fit the right way and no worry's about plunging in it in backwards. But using a product called instomorph which is a low temp melting plastic that you head up the beads in hot water thats 140degrees then
it can be molded with your hands to any shape needed and then when it cools its a very strong plastic very similar to nylon. it also dont seem to stick to any thing very well. So what i did was to use a tiny bit to get the blades held and let it cool. then I took some more and molded it over that and then I pressed it in to the battery so it would form the right shape. and it made a perfect plugs for my multi battery power supply.