These batteries are also wired in series end-to-end-that is, the plus terminal of one battery is connected to the negative terminal of the next. A parallel bank increases amp-hours for longer runtime at the same voltage. To ensure the safety of both the batteries and the individual handling them, several important factors should be taken into consideration. GSL Energy, as a leading provider of lithium-ion energy storage solutions, offers a range of residential, commercial, and. Determine how many batteries you need in series, parallel, or both to meet your system voltage and capacity requirements. Series connection increases voltage, parallel connection increases capacity (Ah). This calculator shows the required arrangement to match your target system specs.