Whenever possible,using a single string of lithium cells is usually the preferred configuration for a lithium ion battery pack as it is the lowest cost and simplest. However,sometimes it may be necessary to use multiple strings of cells. When designing a battery pack, cells can be connected in two ways: in series to increase voltage, or in parallel to increase capacity. Series. Creating your own 60V lithium ion battery pack involves selecting quality cells, designing proper series and parallel configurations, integrating a battery management system (BMS), and assembling with safety and precision. Here's what determines how many "teammates" you need: Power Demand: A typical off-grid cabin uses 5-15 kWh daily, while telecom towers may require 20-50 kWh.