Mower deck What part do I neeed?

I have a Troy-Bilt lawn tractor. I just installed a new fully charged battery in it. It started up fine. After I stopped the mower to clear an obstruction, there was no charge left in the battery to restart it. This same thing happened to the battery that was in it before. What do I need? A battery, starter, voltage regulator, a generator, all or none of the above?

Probably either a stator or voltage regulator and possibly both. I’d have someone with electrical knowledge of how to test these components check it out before you start throw money at it. It would help if you told us the brand of engine you have with model and serial numbers.

Just went out to where the mower stalled and looked at the engine. It's a Power Built 500cc 17.5 hp Briggs and Stratton Engine. The first thing I saw was a white plastic strip with some numbers and a bar code printed it. To read it, I had to wipe off the dirt and grime, and everything printed on it came off, too. Not sure if anything on it could have been useful. Elsewhere I found three numbers embossed in the case. Model: 31c707 Type: 346 b2 Code: 100417z.

Those numbers are the engine numbers so that is a big + 1.
The tag that has Troy bilt ( or had ) it printed on needs to be photographed at 1/2 dozen different angles.
Download the photos to your computer then invert the colours ( called "make negative" in some apps ) and / or push up the contrast.
Where they type was will not be faded and where it was not will be faded.
Our eyes can not resolve white on off white but a computer can.