Autory Lithium Battery Parallel Connection Guide

Connecting Lithium Batteries in Parallel

How It Works

• Parallel connection keeps the same voltage but increases total capacity.
• Example: Four 300Ah batteries at 12.8V = 12.8V 1,200Ah total.
• Common setup for caravans, RVs, marine and off-grid systems.

Key Concerns

• Battery Matching: Use identical brand, model, age, and state of charge.
• Cable Balancing: Keep cable lengths and sizes equal; use bus bars for even current sharing.
• BMS Compatibility: Ensure each battery’s built-in management system supports parallel use.
• Charging: Charge each battery fully once before installation to start balanced.
• Maintenance: Normally no need to disconnect, but check occasionally for imbalance.
• Safety: Install fuses/breakers on each battery before the bus bar; use correctly rated cables and lugs.

Do They Need to Be Disconnected?

• At installation: Yes – fully charge each battery individually once.
• Ongoing use: No – keep them connected; they will balance if wired correctly.
• Occasional balancing: Only if imbalance develops (rare with quality matched packs).

Summary

• Parallel connections maintain the same voltage but increases capacity
• Use equal cabling, bus bars, and fuses for safety and balance.
• No need for regular individual charging after the initial setup.
• Monitoring via shunt or Bluetooth BMS app is recommended for peace of mind.