How Many Kilometers Can a 72V 100Ah Lithium Battery Run?
3 Answers
If calculated based on the theoretical value of a good battery, it can run approximately 200 kilometers. If the battery performance has declined, it can run about 150 to 200 kilometers. Lithium batteries also have both disadvantages and advantages. Disadvantages of Lithium Batteries: All lithium primary batteries have poor safety and pose a risk of explosion. Lithium-ion batteries with lithium cobalt oxide cannot discharge at high currents and have poor safety. All lithium-ion batteries require protection circuits to prevent overcharging and over-discharging. The production conditions are demanding, and the cost is high. Advantages of Lithium Batteries: They have a relatively high energy density. With high energy storage density, currently reaching 460-600Wh/kg, which is about 6-7 times that of lead-acid batteries, they have a long service life, up to more than 6 years. For lithium iron phosphate (LiFePO4) batteries used as the cathode, 1C (100% DOD) charge-discharge cycles can achieve up to 10,000 cycles. They have a high nominal voltage (single-cell working voltage of 3.7V or 3.2V), approximately equal to the series voltage of three nickel-cadmium or nickel-metal hydride rechargeable batteries, making it easy to form battery power packs.
I've been tinkering with batteries for several years. A 72V 100Ah lithium battery has a total energy of 7200Wh. Converted to daily riding, an electric bicycle typically consumes 15 to 20Wh per kilometer. A simple calculation suggests a theoretical range of around 400 kilometers. However, reality isn't so ideal—many factors come into play. For instance, if you ride at a steady speed of 20 km/h on flat terrain, energy consumption is low, potentially reaching 450 kilometers. But climbing steep slopes or carrying heavy loads can spike consumption to 30Wh/km, immediately dropping the range below 300 kilometers. Temperature also plays havoc: in winter, lithium battery activity decreases, reducing range by 20% to just 320 kilometers, while it improves in summer. Battery aging is another factor—performance is best when new, but after two years, capacity may degrade to 80%, cutting range to 350 kilometers. I often advise fellow riders to get handlebar displays with battery level indicators for more accurate real-time estimates, rather than relying solely on nominal values.
I usually commute by electric scooter, and the battery specs are similar to what you mentioned. Based on my experience, on flat city roads at a controlled speed of 25 km/h, a full charge can typically last 300 to 350 km, which is enough for my weekly commute without needing to recharge. However, on a trip to the mountainous area with lots of slopes and extra load, the range dropped sharply to 250 km, and I almost had to push it back to town. Avoid rapid acceleration or sudden braking—maintaining a steady speed is the most energy-efficient. Weather also plays a role; rain, snow, or strong winds can increase power consumption, reducing the range by about 1/4. I’ve tracked data using an app, averaging 18 Wh/km. A new battery can last up to 380 km, but as it ages, it drops to just over 300 km. I recommend keeping a fast charger as a backup and charging more before long trips—safety first.
