Lithium Battery Wiring: Understanding Series vs. Parallel

Series and parallel connections change a battery bank's electrical characteristics. Start with the voltage required by your equipment and the configurations explicitly permitted by the battery manufacturer. This overview explains the concepts; use an approved wiring design for installation.

Series: voltage adds

In a series arrangement of matched batteries, nominal voltages add while the bank's amp-hour capacity remains that of one battery. As an arithmetic example, two matched 12.8 V, 100 Ah batteries would represent a 25.6 V, 100 Ah bank, with 2,560 Wh of nominal energy.

Parallel: amp-hour capacity adds

In a parallel arrangement of matched batteries at the same nominal voltage, amp-hour capacities add. The same two example batteries would represent a 12.8 V, 200 Ah bank, also with 2,560 Wh of nominal energy. These examples do not authorize either arrangement for a particular model.

Check the complete battery and BMS

Confirm series and parallel permission, maximum bank size, supported battery combinations and charger compatibility. The Victron system-design manual provides an example of product-specific configuration and BMS requirements. Its limits are not Gree specifications.

Connecting complete battery packs in parallel does not establish that their internal cells will balance one another. Nor does it guarantee equal current sharing or uninterrupted operation after a fault. Those outcomes require a suitable design and compatible protection.

Have the wiring design reviewed

Ask your installer to specify cable size, routing, connectors, fusing, isolation, terminal torque and the required preparation before connection. Do not select a connector solely by its family name or copy a torque value from another battery. Manufacturer installation instructions illustrate why these details must be checked for the exact model.

Questions to send before ordering

Send Gree Battery support the proposed battery models, quantity, system voltage, inverter or motor, charger and intended layout. Ask for written confirmation of permitted configurations. Do not open sealed packs or bypass their BMS to make a proposed arrangement work. Review our capacity-planning guide alongside the equipment manuals.