A complete analysis of parallel connection of home storage batteries

In our previous article, we described (How to make your own 5kwh home battery pack). This article will guide readers through the process of paralleling and connecting a battery pack to an inverter after assembly.

This article provides a detailed explanation of lithium battery pack aging, parallel communication, and connection to inverters for home storage. It demonstrates how to achieve parallel communication among multiple battery groups through automatic coding, as well as monitor and manage the battery system via a host computer. Additionally, it covers battery reset, key switch function settings, and showcases the charging/discharging of paralleled batteries and their connection to inverters, supporting up to 16 batteries in parallel.

Preparation:

2 or more batteries: Typically supporting 16 series connections between energy storage batteries. Determine the required quantity based on your needs.

Network cable: Prepare a network cable for battery parallel communication using the 468B wiring method. Ensure consistent sequence at both ends; no crossover is needed.

Ⅰ. After completing battery assembly, we must conduct aging tests to ensure performance and safety meet standards, while monitoring charging status in real time via the host computer.

Ⅱ. How Batteries Communicate and Connect in Parallel

First, identify the battery’s communication port. A single port is for external communication (connecting to a computer or inverter). Two ports side-by-side are for the battery’s internal communication protocol.

When connecting two or more batteries, cross-connection is required for communication between the batteries.

Ⅲ. Output Parallel Connection

Before performing output parallel connection, first verify the battery’s parallel current limiting module. Typically, commercially purchased home storage batteries can be directly connected in parallel. If using a self-assembled battery pack, ensure the output current is compatible with the Battery Management System (BMS).

Ⅳ. Battery Coding and Connection to Inverter

Batteries automatically code themselves. If four batteries are connected in series, they will be coded in sequence from 1 to 4. How then do you identify which battery is Battery 1?

Typically, Battery 1 refers to the battery connected to the upper position (computer/inverter). The same applies to the remaining batteries.