Power to the pedal: Achieving longer-lasting 13S, 48-V lithium-ion battery packs for e-bikes and e-scooters


The rise in popularity of electric bikes and electric scooters demands an increasing need for longer-lasting e-bike/e-scooter battery packs. A longer run time allows for further travel and less frequent charging.

To achieve longer-lasting lithium-ion (Li-ion) batteries, you can choose one of two methods: either increase the total battery capacity or improve the energy utilization efficiency. Increasing the total battery capacity means adding more or better battery cells, which can significantly increase the overall cost of the pack. Meanwhile, improving energy utilization efficiency gives designers more usable energy without increasing capacity. There are two ways to improve energy utilization efficiency: increase the state-of-charge accuracy and/or reduce the current consumption.


Go further with longer-lasting 13S battery packs

 charging battery icon View our "Accurate gauging and 50-μA standby current, 13S, 48-V li-ion battery pack reference design."

For a longer run time, you need to pull as much energy as possible from the battery pack; however, the battery will be permanently damaged if overdischarge occurs. In order to avoid battery overdischarge, it is critical to accurately know the battery capacity, or state-of-charge information. There are three ways to accurately measure state of charge:

  • Cell voltage measurement.
  • Coulomb counting.
  • TI Impedance Track™ technology.

Cell voltage measurement is the easiest, but it also has low accuracy overload conditions. Coulomb counting measures and integrates current over time. But achieving better state-of-charge accuracy requires regular full-to-empty learning cycles, and state-of-charge accuracy will be affected by self-discharge and standby current. Low temperatures and an aged battery will also lower state-of-charge accuracy. Impedance Track technology directly measures the effect of discharge rate, temperature, age and other factors by learning cell impedance. Therefore, the Impedance Track method gives you better state-of-charge gauging accuracy even with an aged battery and low temperature.