How long does a 1000W 48V battery last? The battery should be able to last approximately 20 miles at 20 mph. However, this can vary depending upon the terrain and riders’ weight. A 1000W battery is rated at 36 watts per mile. However, these numbers can be misleading, and actual mileage will depend on the terrain, weather conditions, and rider weight. So, you should read the product’s datasheet carefully to ensure you have the right battery for your bike and for your riding style.