Tesla Model 3
For up to 100,000 miles on the standard battery and up to 120,000 miles on the long-range battery.
The battery retention portion of the warranty differs from that of the Model S and X. Neither of those Tesla carry a retention guarantee, nor does Tesla list degradation from battery usage as part of the Model S & X warranty. However, long-term tests have proven that most Tesla suffer only very little degradation over time, far below the 70% threshold put forth by Tesla for the Model 3.
Here's the wording from Tesla in regards to the Model 3 battery warranty and retention guarantee:
Battery and Drive Unit Limited Warranty
Your vehicle's Battery and Drive Unit are covered under this Battery and Drive Unit Limited Warranty for a period of:
•Vehicles with Standard Range Battery - 8 years or 100,000 miles (160,000 km), whichever comes ﬁrst, with minimum 70% retention of Battery capacity over the warranty period.
•Vehicles with Long Range Battery - 8 years or 120,000 miles (192,000 km), whichever comes ﬁrst,with minimum 70% retention of Battery capacity over the warranty period.
This 8-year time frame lines up exactly with the Model S and X, though neither of those vehicles have a listed mileage limit.
As for the more basic new vehicle warranty, the Model 3, like the S and X, gets 4-year, 50,000-mile coverage:
Basic Vehicle Limited Warranty
Subject to separate coverage for certain parts and the exclusions and limitations described in this New Vehicle Limited Warranty, the Basic Vehicle Limited Warranty covers the repair or replacement necessary to correct defects in the materials or workmanship of any parts manufactured or supplied by Tesla that occur under normal use for a period of 4 years or 50,000 miles (80,000 km), whichever comes ﬁrst.
Here are the battery-related warranty details from Tesla's Model 3 New Vehicle Limited Warranty document: