Inverex Inverter Battery Settings: Tubular vs. Lithium

Key Takeaways

• Incorrect battery type selection or voltage settings are the most common causes of battery issues.
• Always verify Program 05 (Battery type) and ensure system voltage (24Vdc or 48Vdc) matches your battery bank.
• NEVER charge a frozen battery.
• Stop DIY troubleshooting and call a technician if the inverter displays internal fault codes (e.g., 08, 09, 53, 57) or if you are uncertain about high-voltage wiring.

How do I correctly set up my Inverex inverter for different battery types?

The correct setup for your Inverex inverter depends on your battery chemistry, such as tubular lead-acid or lithium-ion. You must configure the inverter's battery type and voltage settings to match your specific battery bank to ensure safe and efficient charging. Incorrect settings can lead to undercharging, overcharging, or premature battery failure.

Diagnosis

To ensure your Inverex inverter is correctly configured for your battery type, follow these steps to check the current settings via the LCD display:

1. Check Battery Type (Program 05): Navigate to Program 05 on your inverter's LCD. This program defines the battery chemistry. Options include "AGM (default)", "Flooded", or "User-Defined".
2. Verify System Voltage: Confirm your inverter model (e.g., 1.5KW, 3KW, 5KW) and its nominal DC input voltage (24Vdc or 48Vdc) matches your battery bank's voltage. This is fundamental for all voltage settings.
3. Review Charging Voltages: Check Program 26 (Bulk charging voltage) and Program 27 (Floating charging voltage). These values should align with your battery manufacturer's specifications for the chosen battery type, including any recommended temperature compensation.
4. Examine Low DC Cut-off Voltage: Look at Program 29 (Low DC cut-off voltage). This setting determines when the inverter stops drawing power from the battery to prevent over-discharge.
5. Inspect Equalization Settings (for Flooded Batteries): If you have flooded batteries, check Program 30 (Battery equalization) to ensure it is enabled. Then, review Program 31 (Battery equalization voltage), Program 33 (Battery equalized time), Program 34 (Battery equalized timeout), and Program 35 (Equalization interval). These settings are critical for maintaining flooded battery health. CAUTION --To reduce risk of injury, charge only deep -cycle lead acid type rechargeable batteries. Other types of batteries may burst, causing personal injury and damage. Ensure proper ventilation and follow all safety precautions from your battery manufacturer.
6. Assess Maximum Charging Current: Go to Program 02 (Maximum charging current). This setting limits the total current supplied to the battery from both AC and solar chargers. Ensure it is appropriate for your battery's capacity and recommended charge rate.

Cause/fix table section

Configuring Inverex Inverter Settings for Different Battery Types

The Inverex inverters (rebadged Voltronic Axpert VM III) offer flexible battery settings through their LCD interface. It is crucial to match these settings to your specific battery chemistry to ensure optimal performance and longevity. Menu/program NUMBERING can differ by model and firmware on rebadged units. Readers must match settings by NAME rather than by number.

1. Battery Type Selection (Program 05)

This is the foundational setting that informs the inverter about the general characteristics of your battery bank.

• AGM (default): For Sealed Lead-Acid (SLA) batteries like AGM and Gel. The inverter uses its default voltage profiles for these types.
• Flooded: For traditional wet-cell lead-acid batteries, often referred to as tubular batteries in Pakistan. This option enables specific equalization settings.
• User-Defined: This setting is essential for lithium-ion batteries or if you need to fine-tune voltage parameters beyond the default profiles for AGM or Flooded batteries.

2. Maximum Charging Current (Program 02)

This program sets the total maximum charging current from both solar and utility sources.

Always ensure this value does not exceed your battery manufacturer's recommended maximum charge current.

3. Charging Voltage Settings

These programs define the critical voltage points for charging your battery bank.

For 24Vdc Systems (1.5KW/3KW models)

For 48Vdc Systems (5KW models)

• Note on User-Defined Settings: When using "User-Defined" (Program 05), you have a wide range to set bulk, float, and low DC cut-off voltages. For lithium batteries, these values are critical and must come directly from your battery's specifications or its Battery Management System (BMS). The increment for voltage settings is 0.1V. For lead-acid batteries, always consider temperature compensation as specified by your battery manufacturer.

4. Equalization Settings (Programs 30-35)

Equalization is a feature specifically for flooded (tubular) lead-acid batteries. It is not recommended for AGM, Gel, or lithium batteries. CAUTION --To reduce risk of injury, charge only deep -cycle lead acid type rechargeable batteries. Other types of batteries may burst, causing personal injury and damage. Ensure proper ventilation and follow all safety precautions from your battery manufacturer.

5. BMS Communication for Lithium Batteries

Inverex inverters, being rebadges of the Voltronic Axpert platform, feature a "Reversed communication port for BMS (RS485, CAN-BUS, RS232)". If your lithium battery bank includes a Battery Management System (BMS) with compatible communication protocols, connecting it to the inverter allows for closed-loop control of charging and discharging parameters. This is the safest and most recommended method for managing lithium batteries, as the BMS directly dictates the inverter's behavior based on the battery's state. Always refer to your lithium battery's manual for specific communication setup instructions and required cables.

Safety: Battery Chemistry Considerations

Working with batteries and inverters requires adherence to strict safety protocols.

• Flooded Lead-Acid (Tubular) Batteries: CAUTION --To reduce risk of injury, charge only deep -cycle lead acid type rechargeable batteries. Other types of batteries may burst, causing personal injury and damage.
• Lithium-Ion Batteries: While generally safer, lithium batteries require a robust Battery Management System (BMS) to prevent overcharging, over-discharging, and thermal runaway. NEVER charge a frozen battery.
• General Safety:
• • Qualified Personnel: CAUTION – Only qualified personnel can install this device with battery. Warning!! Only qualified service persons are able to service this device.
  • Insulated Tools: Be very cautious when working with metal tools on or around batteries. A potential risk exists to drop a tool to spark or short circuit batteries or other electrical parts and could cause an explosion.
  • Over-Current Protection: CAUTION: For safety operation and regulation compliance, it’s requested to install a separate DC over-current protector or disconnect device between battery and inverter.
  • Cable Sizing: It’s very important for system safety and efficient operation to use appropriate cable for battery connection. Refer to /pk/tools/cable-sizing-calculator for assistance.

When to call a technician instead

While many settings adjustments can be done by the user, certain situations warrant professional intervention:

• Persistent Internal Fault Codes: If your inverter displays fault codes such as Fault Code 08 Bus voltage is too high, Fault Code 09 Bus soft start failed, Fault Code 53 Inverter soft start failed, or Fault Code 57 Current sensor failed, these indicate internal component failures that require repair by a qualified service center.
• Uncertainty with High-Voltage Wiring: If you are unsure about any aspect of high-voltage DC or AC wiring, or if you need to open the inverter unit, it is best to consult a qualified technician. Opening the inverter unit yourself may void your warranty.
• Complex BMS Integration: If your lithium battery's BMS is not communicating correctly with the inverter, or if you encounter issues with closed-loop control that you cannot resolve with the battery or inverter manuals, a specialist may be needed.
• Safety Concerns: If you detect unusual smells, smoke, or excessive heat from the inverter or batteries, immediately disconnect power sources (PV, utility, and battery) and contact a professional.