Are there mileage limits on a replacement battery from Honda that is just 2 years old?

The battery is not covered under the vehicle warranty, just like tires or brakes.

Its a time limit and is prorated after a certain point the one that was in my 2016 Civic from the factory was a 36 month 24 months free replacement and then prorated for the final 12 months on the 36

Most battery companies use time not miles, check with the battery mfg or your dealer.

You will need to contact the actual dealership for that information.

I would think not should be 8 year replacement when I got mine done