Well if ya'll aren't sure where the battery is you ought to consult your owner manual which will show you diagrams of your engine and give you instructions for replacement, troubleshooting tips and should give you the stats you need to make the right purchase at the store.
Remove the terminals from your old battery and take it to the store with you so you select the correct replacement battery for your Troy Bilt Wide Cut Mower. You need to take the old one with you so that you don't get charged a core fee at purchase.
I have no clue but I can give you advice on how I did it. I knocked on my neighbor's door and said I have nooooo clue what I'm doing... can you help me figure out where the battery is. He ended up doing the entire job.