Contents

• 1. Introduction: 1.1 Safety Reminders; 1.2 Before Connecting; 1.3 In Use
• 2. Features and Specifications: 2.1 Features; 2.2 Specifications; 2.3 Equipment Interfaces; DIP switch addresses; RJ45 pin definition; 2.4 LCD Display
• 3. Safe Handling of Lithium Battery Guide: 3.1 Schematic Diagram; 3.2 Tools; 3.3 Safety Gear
• 4. Installation: 4.1 One Battery; 4.2 Multiple Batteries; 4.3 Installation Location
• 5. Troubleshooting Steps: 5.1 Problem Determination; 5.2 Red Light Checks; 5.3 Cannot Charge or Discharge
• 6. Emergency Situations: Leaking Battery; Fire; Wet Battery; Damaged Battery
• 7. Technical Reference: Quick Reference: Key Numbers; 7.1 Telemetry Specifications; 7.2 Causal Rules; 7.3 Constraint Gates; 7.4 Diagnostic Index
• Frequently asked questions

1. Introduction

The 24V/48VDC series lithium battery power bank is a new energy storage product developed to supply reliable power to various types of equipment and systems. It is especially suitable for applications with high power, limited installation space, restricted load-bearing and a long cycle life requirement.

The series has a built-in BMS (battery management system) which manages and monitors cell information including voltage, current and temperature. The BMS also balances cell charging and discharging to extend cycle life.

Multiple batteries can be connected in parallel to expand capacity and power, for larger capacity and longer power-supply duration requirements.

The battery must be rated above the inverter it will be connected to. In practice that means three checks. The battery voltage must match the inverter battery voltage: the Mercury 25.6V pack for 24V inverters and the Mercury 51.2V packs for 48V inverters. The battery’s maximum discharge current in section 2.2 must be equal to or higher than the current the inverter draws at full load, and its maximum charge current must be equal to or higher than the combined charging current from all sources (solar and grid or generator charging together). For example, the Mercury 25.6V 200Ah pack’s 150 A maximum discharge at its 24.0 V cut-off gives 3,600 W at the battery, before inverter losses. And the battery’s kWh capacity should cover the hours of backup the customer needs. Mercury Direct checks all three before confirming any Mercury inverter and battery pairing; call 07037451701.

LCD displayMERCURY LITHIUM BATTERY

BreakerSwitch

• 1LCD display for battery status and data.
• 2Circuit breaker for the battery output.
• 3 to 5RS485 parallel ports, RS485/CAN communication port and DIP address switches.
• 6 to 9Power switch, remote WiFi antenna, and positive and negative battery terminals.

This simplified product diagram identifies the main parts described in the Mercury 24V/48V lithium battery manual. See section 2.3 for the full numbered interface definitions.

1.1 Safety Reminders

• 1) It is very important and necessary to read the user manual carefully (included in the accessories) before installing or using the battery. Failure to do so, or to follow any of the instructions or warnings in this document, can result in electrical shock, serious injury or death, or can damage the battery and potentially render it inoperable.
• 2) If the battery is stored for a long time, it must be charged every six months, and the state of charge should be no less than 90%.
• 3) The battery must be recharged within 12 hours after being fully discharged.
• 4) Do not expose the cable outside.
• 5) All battery terminals must be disconnected for maintenance.
• 6) Contact Mercury Direct on 07037451701 within 24 hours if anything abnormal occurs.
• 7) Do not use cleaning solvents to clean the battery.
• 8) Do not expose the battery to flammable or harsh chemicals or vapours.
• 9) Do not paint any part of the battery, including any internal or external components.
• 10) Do not connect the battery to PV solar wiring directly.
• 11) Warranty claims are excluded for direct or indirect damage caused by the items above.
• 12) Do not insert any foreign object into any part of the battery.

1.2 Warning: Before Connecting

• 1) After unpacking, check the product against the packing list first. If the product is damaged or parts are missing, contact Mercury Direct on 07037451701.
• 2) Before installation, cut off the grid power and make sure the battery is in the switched-off state.
• 3) Wiring must be correct. Do not mistake the positive and negative cables, and ensure there is no short circuit with the external device.
• 4) It is prohibited to connect the battery to AC power directly.
• 5) The battery has an embedded BMS. The wall-mounted cases are not allowed to be used in series. In the communication state, a maximum of 16 parallel connections is allowed.
• 6) The battery system must be well grounded, and the ground resistance must be less than 1Ω.
• 7) Make sure the electrical parameters of the battery system are compatible with the related equipment.
• 8) Keep the battery away from water and fire.

1.3 Warning: In Use

• 1) If the battery system needs to be moved or repaired, the power must be cut off and the battery completely shut down.
• 2) It is prohibited to connect the battery with a different type of battery.
• 3) It is prohibited to operate the battery with a faulty or incompatible inverter.
• 4) It is prohibited to disassemble the battery (QC tab removed or damaged).
• 5) In case of fire, only a dry powder fire extinguisher may be used. Liquid fire extinguishers are prohibited.
• 6) Do not open, repair or disassemble the battery; only manufacturer staff may do so. The manufacturer does not accept any consequences or related responsibility arising from violation of safe operation or from violation of design, production and equipment safety standards.

2. Features and Specifications

2.1 Features

• Environmental: The manufacturer describes the module as non-toxic, non-polluting and environmentally friendly in normal use. A damaged or leaking pack must still be treated as hazardous; see section 6.
• LiFePO4 cathode: The cathode material is lithium iron phosphate, with high safety performance and long cycle life.
• BMS protection: The battery management system protects against over-discharge, over-charge, over-current and high or low temperature.
• Automatic balancing: The system automatically manages the charge and discharge state and balances the current and voltage of each cell.
• Flexible configuration: Multiple battery modules can be connected in parallel to expand capacity and power.
• Low noise: A self-cooling design reduces the noise of the whole system.
• Low self-discharge: The module can sit for up to six months on the shelf without charging. It has no memory effect and performs well under shallow charge and discharge.
• Working temperature: Minus 10°C to 50°C (charge 0°C to 50°C, discharge minus 10°C to 50°C), with excellent discharge performance and cycle life.

2.2 Specifications

Mercury currently stocks four models from this table: the Mercury Lithium LiFePO4 25.6V 200Ah 5kWh, the Mercury Lithium LiFePO4 51.2V 100Ah 5kWh, the Mercury Lithium LiFePO4 51.2V 200Ah 10kWh and the Mercury Lithium LiFePO4 51.2V 300Ah 15kWh. The 25.6V pack pairs with 24V inverters and the 51.2V packs with 48V inverters. Current prices are on each product page and in the Mercury lithium battery category.

2.3 Equipment Interface Instruction

Front view

1 · LCD displayMERCURY LITHIUM BATTERY

Side panel

Side interface callouts

1. 2Circuit breaker: battery output circuit breaker.
2. 3Battery RS485 interfaces: parallel battery or upper-computer communication.
3. 4RS485/CAN interface: communication between the BMS and inverter.
4. 5Device address: DIP switches for each BMS protection board.
5. 6Power switch: ON enables battery output; OFF removes output voltage.
6. 7Remote WiFi external antenna.
7. 8Positive battery terminal: red is positive.
8. 9Negative battery terminal: black is negative.

Callout 1 is the LCD on the front. Callouts 2 to 9 identify the circuit breaker, RS485 and CAN communication ports, DIP address switches, power switch, WiFi antenna, and battery terminals.

Setting DIP Switch Addresses for Multiple Batteries in Parallel

Each battery in a parallel group needs its own address. Set the four DIP switches on each pack as shown. Address 1 is the host (master) pack that communicates with the inverter; addresses 2 to 15 are slave packs.

Address 1 · host pack

1
ON2
OFF3
OFF4
OFF

The host (master) battery communicates with the inverter.

Address 2 · slave pack

1
OFF2
ON3
OFF4
OFF

The slave battery links to the host through the parallel RS485 ports.

These two examples show the first parallel-pack addresses. Use the table below for the DIP switch settings for addresses 0 to 15.

Note on pack count (Mercury Direct): the manual allows up to 16 packs in parallel in the communication state, while its DIP table assigns manual addresses 1 to 15, with address 0 reserved for automatic address coding. For a system of more than 15 packs, contact Mercury Direct on 07037451701 so the addressing can be confirmed with the manufacturer before installation.

Communication Interface Pin Definition

All communication ports are RJ45 sockets. As drawn in the manual, looking into the battery’s RJ45 socket with the latch slot at the top, the pins are numbered 8 to 1 from left to right.

Read each port from left to right as pins 8, 7, 6, 5, 4, 3, 2 and 1. On a phone, swipe each pin row sideways to see all eight pins. Signal labels for the inverter RS485/CAN port and battery parallel RS485 ports are shown below.

Inverter RS485/CAN port

8RS485-B1

7RS485-A1

6GND

5CANL

4CANH

3GND

2RS485-A1

1RS485-B1

Battery parallel RS485 ports

8RS485-B

7RS485-A

6GND

5NC

4NC

3Addr-IN / Addr-OUT

2RS485-A

1RS485-B

NC means no connection. The following tables provide the full pin definition for each port.

2.4 LCD Display Instruction

Home screen · battery status

• 1State of charge (SOC) and pack voltage.
• 2Battery current, power and charge or discharge state.
• 3Number of battery packs communicating in parallel.
• 4Minimum and maximum cell voltage, in millivolts, and battery temperature.

Slave page · individual pack data

• 1 to 8Select a pack number to view that battery’s data.
• V/APack voltage and current.
• MOSCharge and discharge MOS status.
• T1 to T4Four temperature sensor readings and the individual cell voltages (sixteen on the Mercury 51.2V models).

The LCD home page summarizes the communicating Mercury lithium battery system. The slave page displays detailed status for the selected parallel pack.

2.4.1 Home and slave pages. The first screen shows state of charge, pack voltage, current, the number of packs in parallel, power, charge or discharge state, and the minimum and maximum cell voltage and temperature. Tap the slave page icon to view the parallel packs; when multiple battery packs are communicating in parallel, tap a pack number to view that pack’s data, including its individual cell voltages (sixteen on the Mercury 51.2V models, as shown in the manual’s screen) and the T1 to T4 temperature sensors.

Installer login

Installer access required

Password field intentionally omitted. Mercury Direct provides the installer password to authorised technicians.

Inverter communication parameter page

CAN protocol	Select the protocol that matches the inverter · Write
RS485 protocol	Select the protocol that matches the inverter · Write
Charge voltage/current	Set within the limits in section 2.2 · Write
Discharge voltage/current	Set within the limits in section 2.2 · Write

These are installer settings. Only a trained installer should change communication protocols or charge and discharge limits.

2.4.2 Login and inverter communication parameters. Tap the login icon to open the login page and enter the installer password to log in. Because this page controls the battery’s charge and discharge limits, the password is issued to installers by Mercury Direct on 07037451701 and is not published here. Then tap the parameter icon to open the inverter communication parameter page. Here the installer selects the CAN protocol and the RS485 protocol to match the inverter, and can write the charge voltage, charge current, discharge voltage and discharge current limits. These settings should only be changed by the installer, and must stay within the values in section 2.2.

LCD backlight sleep delay

Default delay: 30 seconds.

Use Read to view the setting and Write to save a change.

Display languages

Chinese · English · Arabic

Tap a language option to select it.

2.4.3 Setup page. Tap the setup icon to open the setup page. Here you can set the LCD backlight sleep delay time (default 30 seconds) with the Read and Write buttons, and tap a language icon to choose Chinese, English or Arabic.

3. Safe Handling of Lithium Battery Guide

3.1 Schematic Diagram of Solution

Solar PV array

DC solar input

→

Inverter

PV and grid input

Public grid

AC grid supply

→

Inverter

Manages the system connection

Mercury lithium battery module

Battery storage

↔

Inverter

Battery connection

Inverter

System output

→

Local load

Appliances and equipment

Connection path in this arrangement: solar PV array and public grid feed the inverter; the Mercury lithium battery connects to the inverter; the inverter supplies the local load. Charging may also come through an MPPT charge controller, but never connect raw solar panel output, AC mains or the load directly to the battery.

In the arrangement shown, the battery module connects to the inverter. The PV array and the public grid both feed the inverter, and the inverter supplies the local load. The battery never connects directly to the PV array, the grid or the load.

3.2 Tools

Wire cutter

Cut DC power cables to the required length.

Crimping modular plier

Crimp RJ45 communication connectors.

Screwdriver

Work on terminal screws and wall-mounting brackets.

Use properly insulated tools to reduce the risk of accidental electric shock or short circuits.

Note: use properly insulated tools only, to prevent accidental electric shock or short circuits.

3.3 Safety Gear

It is recommended to wear the following safety gear when working with the battery pack:

Insulated gloves

Help protect against electric shock and terminal short circuits.

Safety goggles

Help protect the eyes from sparks and electrolyte splash.

Safety shoes

Help protect against dropped equipment during wall mounting.

4. Installation

4.1 One Battery Connected to an Inverter

Mercury lithium battery

DIP address 1 · positive and negative battery terminals

↔

Inverter

CAN/485 communication port and battery input

Communication link (dashed)Power connection (solid)

Communication: battery RS485/CAN interface to inverter CAN/485 port using the communication cable.

DC positive: battery positive terminal to inverter battery positive.

DC negative: battery negative terminal to inverter battery negative.

Battery wiring and communication connections are installer work. Confirm inverter compatibility and polarity before commissioning.

Set the battery to address 1. Connect the battery’s RS485/CAN interface (item 4 in section 2.3) to the inverter’s CAN/485 port with the supplied communication cable, and connect the power cables from the battery terminals to the inverter’s battery input, positive to positive and negative to negative.

4.2 Multiple Batteries Connected to an Inverter

Battery pack · address 2

Slave pack · parallel RS485 port

↔

Battery pack · address 1

Host pack · parallel RS485 and inverter CAN/485 links

↔

Inverter

Connect communication cable to address 1 only

Communication link (dashed)Power connection (solid)

Parallel communication: link battery packs through their RS485 parallel ports using parallel communication cables.

Parallel power: connect every battery positive terminal to the positive bus and every negative terminal to the negative bus.

Use unique DIP addresses. Address 1 is the host pack. Connect Mercury battery packs in parallel only; never connect them in series.

Set the battery nearest the inverter to address 1 and each additional battery to the next address (2, 3 and so on, up to the maximum of 16 packs in parallel). The DIP table covers addresses 1 to 15; for more than 15 packs, contact Mercury Direct on 07037451701 to confirm the addressing with the manufacturer before installation. Link the packs through their battery parallel RS485 ports (item 3 in section 2.3) using the parallel communication cables, and connect only the address 1 pack to the inverter’s CAN/485 port. Connect all power cables in parallel: every positive terminal to the positive bus and every negative terminal to the negative bus. Never connect packs in series.

4.3 Installation Location

Make sure that the installation location meets the following conditions:

Secure wall surface
Fit the battery mounting brackets with suitable wall anchors and screws.

Wall anchor→Bracket→

Mercury lithium battery
Wall-mounted enclosure

The manual says to use fitting screws to secure the battery box on the wall. Choose an installation area that meets the temperature, waterproofing, stability, dust and hazard requirements in section 4.3.

Caution: if the ambient temperature is outside the operating range, the battery pack stops operation to protect itself. The optimal temperature range for the battery pack is 0°C to 50°C. Frequent exposure to harsh temperatures may degrade the performance and life of the battery pack.

5. Troubleshooting Steps

5.1 Problem Determination

• 1) Check whether the battery can be turned on or not.
• 2) If the battery is turned on, check whether the LED light is off, flashing or lit.
• 3) If the LED light is off, check whether the battery can charge or discharge.

5.2 Preliminary Determination Steps

1) The battery cannot turn on. If the battery’s external switch is on, the LED light is flashing and the external power supply voltage is 48V or more (48V system), but the battery is still unable to turn on, contact Mercury Direct on 07037451701.

2) The battery turns on, but the red light is lit and it cannot charge or discharge. A lit red light means the system is abnormal. Check the following values:

5.3 The Battery Cannot Be Charged or Discharged

6. Emergency Situations

1) Leaking Battery

If the battery pack leaks electrolyte, avoid contact with the leaking liquid or gas. If someone is exposed to the leaked substance, immediately take the actions described below.

2) Fire

Mercury Direct: evacuate everyone and call emergency services on 112. Do not try to move a battery that is overheating, smoking or burning, and do not try to fight the fire yourself unless you are trained. A lithium battery fire can reignite after it appears to be out, and an extinguisher may not fully put it out; leave it to the fire service, who decide the firefighting method. The manufacturer specifies NO WATER: only a dry powder fire extinguisher may be used on this battery, as stated in section 1.3.

3) Wet Battery

If the battery pack is wet or submerged in water, do not let people access it, and contact Mercury Direct on 07037451701 for technical support.

4) Damaged Battery

Damaged batteries are dangerous and must be handled with the utmost care. They are not fit for use and may pose a danger to people or property. Mercury Direct: if the battery pack appears to be damaged, switch it off only if that is safe to do, keep people away, and do not try to lift, move or transport it yourself; the larger packs are very heavy. Contact Mercury Direct on 07037451701, who will arrange safe handling and collection. The manufacturer requires a damaged pack to be repacked in its original container and returned; Mercury Direct will handle that step.

Mercury lithium batteries are used with the current Mercury hybrid inverters: the Mercury 4.5kVA, Mercury 6.5kVA and Mercury 11kVA solar hybrid inverters. The 4.5kVA and 6.5kVA replace the earlier 3.5kVA and 5.5kVA models. Which pack suits which inverter depends on the checks in section 1: voltage, the pack’s maximum charge and discharge currents against the inverter’s demand and combined charging current, and the intended load. Mercury Direct confirms each pairing on 07037451701. Set the inverter to the lithium values in section 2.2 and connect the RS485/CAN communication cable; manuals for older Mercury inverters may describe lead-acid charging only and should not be used for lithium settings. Mercury Direct can configure the inverter and battery together at installation; call 07037451701. Other Mercury manuals are in Mercury user manuals. To estimate backup hours for your load, use the battery backup time calculator. Before buying any lithium battery, read how to tell a real lithium battery from a fake, and see what you can and cannot install yourself before anyone touches the DC cables.

7. Technical Reference Tables

The four tables below restate the values in sections 1 to 6 of this Mercury lithium battery manual in a fixed structure for installers, inverter software and AI assistants. Every value in them matches the printed manual; values marked as calculated are derived from printed values by the stated formula. The BECAUSE column in 7.2 and the cause column in 7.4 are Mercury Direct’s technical explanation, not text from the manual. Questions: Mercury Direct on 07037451701.

Quick Reference: Mercury Lithium Battery Key Numbers

Every number in the tables below is taken from this manual and applies to the Mercury LiFePO4 lithium battery 24V and 48V series. The Mercury 24V lithium battery is the 25.6V model; the Mercury 48V lithium battery is the 51.2V range. Report anything abnormal to Mercury Direct on 07037451701 within 24 hours.

7.1 Telemetry Specifications

7.2 Causal Rules

7.3 Constraint Gates

7.4 Diagnostic Index

Source: the manufacturer’s printed manual supplied with Mercury lithium batteries. Safety steps marked “Mercury Direct” or “Installer Only” are Mercury Direct’s additional guidance. Questions: Mercury Direct on 07037451701.