Every morning now for the last five consecutive days my vehicle has stalled every morning when I start it up. Then you can crank it up again and no problem. Do you guys think it might be my battery?

 

No, it's not your battery. It's the ECU having a little brain fart because the climate conditions in your area may have changed lately (air temp, barometric pressure, humidity, etc.). Many S2000's experience this at some point during the year. Eventually, it should learn to deal with it UNLESS you've been trying to "help" it by giving it gas to prevent it from stalling. This only confuses it even more and will take that much longer to learn. It needs to figure out on its own based on throttle position (which you might mess with if you use the gas), MAP readings, etc.
Have you been trying to help it? If yes, stop and give it more time. If not and it continues to do this for a couple more days, then I would suggest you unplug the MAP sensor wiring harness and wiggle it firmly back on. Reset the ECU by pulling the BACk UP fuse for 1/2 a minute. If it doesn't learn on its own, you've got nothing to lose by resetting the ECU. Be prepared for it to do it again next year about this time if you do reset it. Mine took 3 years before it stopped doing it at more or less the same time each year.

 

you're gonna hear a lot of "advice" about this popular topic. but you got the best advice you're gonna get right there.