Author: Jasmeen Aneja

If you have a large battery bank and you are looking to speed up charging, a parallel configuration with two TRUEcharge3 chargers is an ideal solution. By combining the output currents of two chargers, you essentially double the charging power, reducing downtime and ensuring that your power system is ready for action. This guide provides an in-depth look at the setup and installation process, with a focus on essential safety and functionality requirements.

Why Choose a Parallel Configuration?

In a parallel setup, two TRUEcharge3 chargers work in sync to provide a combined output current. For example, pairing two 40-amp TRUEcharge3 chargers results in an 80-amp charging capacity, ideal for larger battery banks that demand higher power to reach full charge quickly. Note: Parallel configuration requires the TRUEcharge3 Remote Panel (PN: 808-8040-10), which synchronizes the two chargers and ensures smooth, reliable operation.

Installation Pre-requisites

Before diving into the installation, ensure the following conditions are met to avoid equipment damage or inefficient operation:

Matching Output Voltage and Current: Both chargers must have the same output voltage and current rating. For instance, pair two 12V 40A chargers or two 24V 30A chargers, but never a 12V with a 24V or 20A with an 30A.

Remote Panel Requirement: Both chargers must be connected to the TRUEcharge3 Remote Panel to function in parallel.

Correct Mounting and Wiring: Install each charger securely and per the setup guide to prevent any operational issues.

Step-by-Step Guide for Setting Up a Parallel Configuration

Step 1: Mount the Chargers Securely

Choose a well-ventilated, dry location for each charger. Mount them following the specific instructions provided below:

Connecting the DC Chassis Ground

Locate the Ground Stud: Each charger has a dedicated ground stud for DC grounding.

Connect to Ground Bus: Attach each charger’s ground stud to the ground bus using a flat washer, lock washer, and nut from the installation kit.

Tighten: Secure the ground connection by tightening the nuts to 2.3 N-m (20 lb.-in.) torque. Avoid over-tightening, this may damage the equipment or compromise the connection.

Install DC Wiring

Plan the Wiring Route: Plan a direct path for the DC wiring from each charger to the battery banks, ensuring a safe and efficient setup.

Label Wires: Clearly mark positive and negative cables. Use red for positive and black for negative, as recommended by standard marine codes.

Install Circuit Breakers: Place a DC circuit breaker or fused disconnect in each positive cable, close to the battery’s positive terminal.

Connect the Wires: Route the cables from the chargers directly to the battery banks, avoiding intermediate devices that could cause voltage drops. Attach each wire securely to prevent looseness or shorts.

Install AC Wiring

Route AC Wiring: Plan the route from the power source to each charger, ensuring the cables remain undamaged and properly secured.

Prepare the Wires: Strip the outer insulation from the AC wiring, taking care to avoid damaging the inner conductors.

Connect the AC Wires: Attach the AC supply wiring (L, N, G) to each charger, using the color-coded pigtail leads provided. Ensure that each connection is secure.

Use a Double-Pole Breaker: Connect both chargers to the same AC circuit branch with a double-pole breaker. This setup synchronizes the chargers and helps avoid potential issues with unsynchronized currents.

Initial Power-Up for Parallel Setup

Switch on DC Power: Start by closing the DC disconnect switches or breakers.

Turn on AC Power: Next, turn on the AC breaker. You should see a brief delay as the chargers initialize, indicated by flashing LEDs on each unit.

Step 2: Designate Primary and Secondary Chargers

Once the chargers are powered up, select one as the primary charger and the other as the secondary. Only the primary charger (charger connected to the primary terminal on the remote panel) or the remote panel itself should be used to configure and control the parallel system.

Step 3: Configuring the Battery Banks

Connect Battery Banks: Link the positive and negative terminals of the primary charger’s battery bank 1 to the secondary charger’s battery bank 1. Repeat this step for battery banks 2 and 3.

Note: You can connect a maximum of three battery banks in a parallel configuration.

Leave Unused Outputs Unconnected: Disconnect any unused DC outputs from both chargers to avoid accidental connections.

Step 4: Connecting the Remote Panel

Connect Communication Cables: Attach the remote panel’s communication cables to the primary charger’s remote port (labeled Primary) and to the secondary charger’s remote port.

Connect Battery Temperature Sensor: If you’re using a Battery Temperature Sensor (BTS), connect it to the primary charger’s BTS port. For dual BTSs, connect one to each charger. The BTS with the higher detected temperature will manage temperature adjustments.

Read this blog to understand and configure TRUEcharge3 Battery Temperature Sensing functionality.

Powering Up and Synchronizing the Chargers

Power On the Chargers: Once all connections are in place, turn on both the DC and AC power sources.

Observe Parallel LED: The Parallel LED on the remote panel will light up, indicating the chargers are synchronized and functioning in parallel.

During charging, the remote panel displays the combined output of both chargers. As your battery nears a full charge, one charger may reduce its output sooner than the other—this is normal and helps prevent overcharging.

Configuring and Operating the Parallel Setup

You can configure and monitor both chargers through the primary charger or the remote panel. The settings on the secondary charger will automatically synchronize with the primary charger, allowing for consistent and easy management.

Battery Equalization during Parallel Charging

Equalization can be programmed and monitored from the remote panel, ensuring balanced charge distribution across battery banks.

Fault and Warning Monitoring

If one charger encounters a fault, the other continues operating. The remote panel will display the fault condition, stopping synchronization temporarily until the issue is resolved.

Exiting Parallel Operation

To exit parallel mode, completely power down the chargers and disconnect both communication cables from the remote panel.

Setting up TRUEcharge3 chargers in a parallel configuration provides a flexible, powerful charging solution for larger battery banks. By following this guide and meeting all prerequisites, you’ll be able to safely and effectively double your charging capacity, ensuring your batteries stay healthy and ready for your next adventure.

Upgrading your house battery bank to lithium is a game-changer. Lithium iron phosphate (LiFePO4) batteries offer longer lifespan, faster charging, and reduced weight compared to traditional options like AGM or flooded batteries. They have the benefits of the high capacity like lead-acid, but deep the discharge of lithium. But here’s the real question: do you need a lithium charger to keep them running at their best?

It’s tempting to stick with your current charger, especially if it’s been reliable for years. However, lithium batteries have unique charging requirements. They operate at higher voltages—typically 14.4 to 14.6 volts—to reach a full charge. A non-lithium charger might leave your batteries stuck at 80–90%, leaving power on the table and gradually reducing their capacity over time.

Why the Right Charger Matters

Lithium batteries also don’t require trickle or maintenance charging. Using a charger designed for lead-acid batteries can confuse the battery’s internal Battery Management System (BMS), leading to errors or even temporary shutdowns. Over time, this can chip away at your battery’s performance and lifespan.

And then there’s the insurance angle. If your charger isn’t compatible with lithium and something goes wrong—whether it’s a fault or a failure—your insurance provider could deny a claim. Many policies require that your setup follows the battery manufacturer’s guidelines. Having the right charger isn’t just about performance; it’s about protecting your investment.

The TRUEcharge3 Battery Charger is purpose-built for house battery banks, offering optimized lithium charging to ensure you’re getting all the performance you’ve paid for.

Charging Lithium While Underway

Charging lithium batteries while cruising brings another challenge. Lithium batteries can draw a lot of current, which can overheat or damage your alternator.

If you’re running an inboard engine, consider adding an alternator regulator with a lithium profile. For outboard engines or simpler setups, a DC-to-DC converter with lithium settings is a great choice. These solutions protect your alternator while delivering the charge your lithium batteries need. Pairing these with a dockside charger like TRUEcharge3 ensures your house batteries are optimally charged.

Protecting Your Investment

Lithium-specific chargers are designed to:

· Fully charge batteries to 100%, maximizing capacity and longevity.

· Balance cells for long-term performance.

· Avoid incompatible charging modes that can harm batteries or cause errors.

While AGM or flooded profiles may work temporarily, they often leave lithium batteries undercharged, leading to premature capacity loss. Over time, this could cost you more in replacements and repairs—not to mention potential insurance headaches.

Switching to lithium batteries is an upgrade you’ll appreciate every time you’re out on the water. But to get the most out of them, it’s important to pair them with the right charger. Whether you’re adding a lithium-compatible dockside charger like the TRUEcharge3 or a DC-to-DC converter for underway charging, the investment is worth it.

The new TRUEcharge3 Remote Panel transforms the way you monitor and control your charging system. Designed to bring flexibility and control to your fingertips, this remote allows you to keep tabs on battery health, adjust settings, and activate features without ever having to reach your charger. Whether tucked away in a cabinet or mounted deep in your setup, the TRUEcharge3 charger becomes easy to manage—perfect for making the most of every journey on the water or road.

Why the TRUEcharge3 Remote Panel Makes a Difference

The TRUEcharge3 Remote Panel is like a fuel gauge for your charger, giving you essential insights into your battery’s status and charging progress. Equipped with a clear display and advanced controls, the remote panel helps you keep your power system running smoothly without hassle. Plus, it’s designed to be quick to install and easy to use, so you can spend less time adjusting settings and more time enjoying the open water or the open road.

Key Features for Ultimate Control and Convenience

This remote pairs seamlessly with all TRUEcharge3 charger models in 12V and 24V configurations, adding new levels of convenience and reliability to the charging experience. Here’s a closer look at what makes it so useful:

Fault and Error Display: The remote panel displays fault codes and warnings in real-time, helping you troubleshoot any issues with ease.

Remote Charger Control: Switch your charger output on or off without having to access the charger itself. This feature is especially handy when the charger is installed out of reach, letting you stay in control from anywhere on board.

Adjustable Output: Tailor the charger’s output to match your power needs, with options from 20% to 100% capacity. This adjustability gives you peace of mind, knowing your power draw can be adjusted as needed.

Battery Status at a Glance: Get a clear view of each battery’s State of Charge (SOC) and the current going into each battery bank. This instant insight into your battery health is invaluable for making quick, informed decisions.

Parallel Charging: Need more power? The remote panel supports parallel stacking of two chargers, giving you up to twice the output current for those times when you need extra charging capacity.

Quiet Mode Activation: Enjoy quieter charging at night by activating Quiet Mode from the remote panel. It’s perfect for low-noise, uninterrupted sleep, whether in the comfort of a cabin or on a peaceful night at anchor.

Temperature Control: Choose the right battery temperature setting—Cold, Warm, or Hot—to ensure optimal charging based on your environment, all with the touch of a button.

Easy to Install and Ready to Use

With the same form factor as previous models, the TRUEcharge3 Remote Panel is easy to install and fits seamlessly into most setups. It connects to the charger with the included telephone cable, making installation quick and simple. Once mounted, this remote becomes an indispensable addition to your charging system, putting total control and peace of mind within reach.

Note: The TRUEcharge3 Remote Panel is compatible exclusively with the TRUEcharge3 series chargers.

Bringing Convenience to Your Charging System

With the TRUEcharge3 Remote Panel, managing your charging system becomes a breeze. Designed for those who value reliable power and simplicity, this remote panel ensures your charging setup is always accessible, easy to monitor, and adaptable to any journey. Whether preparing for a new day on the water or winding down for the night, the TRUEcharge3 Remote Panel is a tool built for freedom, reliability, and ultimate control.

For a system that keeps your batteries in peak condition with minimal effort, the TRUEcharge3 Remote Panel is the perfect addition to complete your charging experience.