Ultimate Guide to Lithium Battery Parallel Connection: JKBMS PB Series

Ultimate Guide to Lithium Battery Parallel Connection: JKBMS PB Series

Connecting multiple lithium battery packs in parallel is a popular method to expand system capacity. However, without proper management, it introduces the critical risk of cross-currents (circulating currents). This guide explains how to safely parallel JKBMS systems.

JK BMS Battery Parallel Connection Guide Overview

The Danger of Cross-Currents

When battery packs with unequal voltages are connected in parallel, the pack with the higher voltage will rapidly charge the lower-voltage pack. This massive surge of current can trigger overcurrent protection, damage cells, or even lead to thermal runaway.

3 Methods for Paralleling Lithium Batteries

Method 1: Systems 8S and Below (Direct Parallel)

For low-voltage systems (12V/24V) using 8S cells or fewer, you can typically parallel packs directly.

  • Connection: Connect main Positive (+) to Positive and Negative (-) to Negative.
  • Crucial Rule: Both battery packs must be top-balanced and at the exact same voltage level before the final connection.

Method 2: Systems Above 8S (Requires Balancing Modules)

For high-voltage systems (e.g., 16S 48V), direct parallel connection is strictly forbidden. You must use dedicated hardware to manage the current flow.

JK-BLMK-5A Parallel Balancing Module

Figure 2: JK-BLMK-5A Current Balancing Module.

Required Hardware: At least two JK Parallel Modules (e.g., BLMK-5A) and BMS boards with specific parallel communication logic.

Wiring logic consists of 3 sets:

  • Wiring Set 1 (D0): Communication link via the dedicated D0 parallel port.
  • Wiring Set 2 (B+): Connection to the main Total Positive terminal.
  • Wiring Set 3 (B- & P-): Respectively connected to the B- and P- ports on the BMS module.
BMS Parallel Logic Diagram Wiring Set 1: D0 Communication Wiring Set 2: B+ Connection Wiring Set 3: B- and P- Connection

Method 3: The Best Solution - JK BMS PB Series

The **JK BMS-PB Series** is specifically designed for high-capacity energy storage systems (ESS). It eliminates the need for external modules.

  • Native Support: Built-in parallel management circuitry supports up to 16 packs in parallel.
  • Plug-and-Play: No complex external wiring for current balancing.
  • Inverter Integration: Features integrated CANBus/RS485 for seamless communication with hybrid inverters like Victron, Growatt, and Deye.

Conclusion

For professional 48V solar storage systems, the PB Series is the most reliable and cost-effective choice. It ensures your parallel packs operate in harmony, protecting your investment and ensuring power stability.

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