Installation Guidelines

This section of the Procedure Guide covers procedures that are related to the installation. You will most likely use these procedures when Installation of Battery..

Installation Procedure

Discharge Characteristics

Connector Installation

Float Service Life

Environment & Condition of Use

Cycle Service Life

Safety Precautions while Installation

Recharge Time Characteristics

Charging characteristics

Charging method for cyclic applications

Freshening Charge

General reasons for battery failures



Installation Procedure

Install the battery in a clean and dry location. A minimum of 0.5meters of space should be provided on four sides of the battery


The MAXLIFE Batteries is a valve regulated maintenance free battery and gas evaluation is minimum, hence normal room ventilation as per local building regulations is sufficient

The MAXLIFE battery stack consists of floor mounting channels, and stackable battery modules. The battery stack layout drawing is provided with every consignment for ready reference and it is recommended to install the battery accordingly


If floor anchoring is required, mark location and install floor anchors and match the anchor holes with floor mounting channel. Install the floor-mounting channel depending on the system configuration in accordance with the lay out provided.

All electrical contacting surfaces must have clean, bright oil free finish. Wipe with dry cloth factory-applied petroleum jelly on the terminals clean the dust if any from the contact area of the battery terminals. Brush the contact surfaces of the battery terminals and connectors to a bright finish.

All cells are pre assembled in the stack modules with the cell polarities oriented to provided simple interconnections.


Connector Installation

  • Inter connect cells and modules with the lead plated copper connectors.

  • The connectors provided are numbered and the same are to be connected according to the lay out.

  • Take extreme care when installing connectors.

  • Maintain a firm grip to prevent it from dropping and potentially causing a short circuit

  • All the connectors should be connected from top module to bottom module.

  • Over torqueing could damage the post seal and terminal integrity permanently

  • Loose contacts could cause poor performance and sparking which can lead to fire.


Environment & Condition of Use

  • Do not install VRLA Battery in airtight cabinets / equipment, which may cause explosion..

  • Do not place the battery near a device that may cause sparks / flame.

  • Avoid placing the battery near the heat source, such as transformers which are prone to get over heated during operation.

  • Battery Charging voltage settings to be followed strictly according to the manufacturer recommended when the batteries are operated at below or above 27 C.


Safety Precautions while Installation

  • Using un insulated tool may cause a short circuit and could result in burns / damages to the battery.

  • Take safety measures such as wearing rubber gloves when handling a voltage of 48V or higher

  • Avoid rough handling

  • Do not carry the battery by hanging it from the terminals. Use material handling equipment like fork lifts, chain pulley etc.

  • Do not under estimate weight of the battery. Because of the lead, it is heavy for its volume

  • Do not apply organic solvents such as thinner/gasoline/kerosene/liquid detergent to the battery.

  • Do not cover the battery with a material which generates static electricity such as a PVC sheet.

  • While tightening the terminals bolts of the battery apply a torque of 1.10kgf.m with torque wrench only.

---------x-------- The battery should be installed by a skilled personnel only -------x----------


Charging Characteristics

  • The life of lead acid battery is often considered to be a functional choice of raw materials, and design parameters such as grid alloy and grid thickness, paste composition.

  • Electrolyte concentration and operational conditions such as rate of discharge, depth of discharge, operating temperature. Charging can also have significant effect on life of the battery

  • The MAXLIFE batteries must be charged only at constant voltage with a current limited to 0.25 at C10.

  • The lead sulphate of the positive plate becomes lead peroxide.

  • When charging continuously, the positive plate generates O2 which in turn raises the battery voltage.

  • A constant voltage charge controller senses the voltage increase and control the charge amount

Charging for float applications:

Conventional CV float charging is a delicate process in which the energy applied to the battery string is not sufficient to charge to 100% SOC (State of Charge) during the float.

Some cells may have high voltage due to gassing; water loss and some cells will have low voltage due to partial discharge of negative plate.

Charge voltage / boost charging of VRLA Batteries at higher voltage than float voltage is the only way to recharge negative electrodes that suffer continual discharge and to maintain desired state of charge during service life

Cyclic Charging:

In cyclic charging the conditions of partial state of charge is common. Undercharging will have severe impact on service life of MAXLIFE VRLA Battery.

Safety Precautions during Charging:
MAXLIFE batteries are very safe; however simple safety precautions are to be followed as follows.
Use only direct current for charging; be sure charger is switched off before making the connections.
Be sure charger is switched off before making the connections.
All tools used should be insulated to avoid shorting of terminals
Connect battery positive terminal to the charger positive and battery negative terminal to the charger negative terminal.
Be certain that all connections are tight before switching on the charger.
Do not tamper cell cover or vent plug.

Safety Precautions During Charging:
Do not move the battery stack after installation without disconnecting the load and inter cell connections.
Do not allow metal objects to rest on the battery or fall across the terminals.
Never wear metal wrist band or metallic watch straps while working on the battery.
Keep the battery in a clean and dry location


Freshening Charge

  • All batteries are shipped fully charged.

  • Provide freshening charge in accordance with recommended charge due date given on the instruction label

  • MAXLIFE Batteries must receive a boost charge, if open circuit voltage drops to 2.10V/ cell or if installation will not occur in 6 months of shipping date from the factory

  • All lead acid batteries lose a certain amount of charge when they are stored in open circuit condition.

  • When the batteries are stored at higher temperature than normal storage temperature of 27C., then the batteries suffer an accelerated self-discharge by a factor of 2 for each 10C.

  • This in turn will reduce the storage time before initial charging.

  • The MAXLIFE batteries are equipped with a pressure regulated safety valve, flame arrestor that seals the cells during normal operation but allows it to safely vent incase of over charge.

  • Freshening charge to be carried out at the recommended float voltages for a minimum of 72 hours before load is connected.

Removing the Valve Assembly (Vent Plug) can cause permanent damage to the battery and will void the warranty

Record voltage of the individual cells, the battery voltage and ambient temperature on monthly basis.
Freshening charge records are essential for review by NED service engineer in the event of problem solving.


Over Charging

Higher than the normal battery voltage, with in float/charge voltage settings can damage a battery drastically, shortening its effective service life. Improperly set / improperly calibrated panel meters may result in battery over charge. Valve regulated lead acid batteries are very sensitive for over voltage charging. The following are the problems when the battery is exposed over voltage charging. Over charge accelerates gas generation and it may lead to premature dry out of the battery. A small increase in over voltage will increase the corrosion of the positive grid and it will lead to a reduced battery service life.

Discharge Characteristics

The capacity obtained from a battery during discharge mainly depends on the rate of discharge and on the operating temperature. The capacity at any other rate other than C10 up to specified end voltage as mentioned is inversely proportional to rate of discharge.

This relation is at one rate to another is not linear.

Discharge Characteristics at Various Rates of Discharges:


Float Service Life

The expected life of MAXLIFE is about 10 years. This is based on normal service conditions, where the float charging voltage is maintained at 2.25V +/- 0.02Volts per cell at an ambient temperature of 27C.


Cycle Service LIfe

There are several parameters which affect the number of cycles such as temperature, discharge rate, depth of discharge (DOD), and charging methods etc., out of which DOD is the most important factor.


Recharge Time Characteristics

Recharge time is a function of rate, depth of discharge, recharge voltage, maximum charging current, desired SOC and temperature


Charging Method for Cyclic Applications

  • Number of Cycles per day = 2 Numbers

  • Low voltage cutoff should be 23.5/47 V for 24/48V battery system respectively or 4 hours whichever occurs first. Charging time should be 8 hrs after every discharge Charging current should be 15%.

  • Charging voltage to be set @ 2.33V to 2.35V per cell i.e. 27.96 to 28.20 Volts for 24Volts system and 55.92 to 56.40 Volts for 48Volts system. After every 30 days battery should continuously charge for 22 hrs with boost voltage settings.

  • Constant Potential, current limits charging as per DIN 41773 to be followed.

  • Equalization charge should be done after every 6 month (NED will provide training to field staff)
Details of Equalizing Charging:
The charger should have IEI Characteristics as per DIN 41773. Equalization charge is essential when improper / inadequate charging is performed. It has to be administered once in 6 months Details of Steps:

Step-1: With constant current & 0.15C up to voltage of Battery Bank reaches 56.40V (2.35VPC) as a period of 11 hours.
Step-2: Automatically switch to constant voltage mode @56.40V for a period of 10 hours.
Step-3: Automatically switch to constant current mode with current of 0.6A for 3 hours.

The user shall follow strictly instructions as per installation and operating instructions manual Ref. No.: ML/IOM/01/01. The user shall give freshening charge to all cells once in 6 months at least from the date of factory charge when stored at 27C or otherwise in accordance with storage conditions of manual Ref. No.:ML/IOM/01/01.

Battery charging voltage, recharge time shall be maintained accordance to installation and operating instructions manual Ref. No.:ML/IOM/01/01.

In case of transit damages if any the same has to be informed to the manufacturer with in 7 days from the date of receipt.
The right to determine whether a battery/cell requires repair / replacement lies with NED ENERGY LIMITED

General Reasons for Battery Failures

MAXLIFE SERIES batteries should give many years of trouble free service provided that operating instructions are followed strictly. The following points help in ensuring expected battery life.


  • Standby batteries are specifically designed to provide long life in continuous float services. Generally these batteries are float charged continuously in parallel with the load, ready to supply DC power.

  • Depth of Discharge, Frequency of Discharge, Rate of Discharge and interval between subsequent discharges, charging voltages and battery operating temperatures are all determining in the battery life.

  • For long service life, cycling should be kept to a minimum

  • Recharge batteries as soon as possible of every discharge and do not leave the batteries in discharged condition

  • Strictly Charge the MAXLIFE VRLA battery as per recommended charging voltage and time for optimum life and performance

  • Either charger is switched off by mistake or faulty charger setting or frequent discharges, the result would lead the battery to partially charged condition, which will cause low cell voltages and the plates will be prone to sulphation.

  • Immediately check the charger set point for voltages by disconnecting the load and charge the batteries continuously for 24 hours at 2.25V/cell before connecting the load.

  • VRLA batteries maintained at partial SOC condition or undercharging, the impact of undercharging is savior on service life of VRLA batteries hence it is to be avoided.

  • If low voltage/ sulphated cells are allowed to remain in a partially charged condition for an extended period of time, then irreversible damage occurs requiring replacement.

If the batteries are over discharged and left in a discharged condition without immediate recharge, battery degradation will occur. However MAXLIFE batteries are more resistant for repeated deep discharges and revival of battery is simple by extending the period of charging. Avoid deep discharges and recharge the batteries immediately after every deep discharge. Do not leave the battery in a discharged condition

Batteries are subjected to the Electro-Chemical local actions during storage (This phenomena is called self discharge) Self discharge of MAXLIFE batteries are expected to occur at the rate of 5% per month at 27C. If the batteries are stored in open circuit (no charging) for prolonged periods, then sulphation occurs requiring corrective action. Batteries to be stored at room temperature (not exceeding 27C) and the batteries need to be charged at least once in six months.

For increasing the battery bank capacity it is common practice to connect the equal voltage battery strings in parallel. When paralleling if the MAXLIFE batteries, extreme care to be taken by maintaining the external circuit length identical for each battery string and all the connections to be tightened using a torque of 1.10Kgf.m with torque wrench only.

Any variation in circuit resistance i.e. string to string resistances may result in unequal charge and erratic performance

The following are the possible causes for low cell voltages

Sl.No.   POSSIBLE CAUSE   Recommended corrective action
1   Panel volt meter reading high   Recalibrate the panel voltmeter voltage correctly.
2   Poor inter cell and terminal contacts   Tighten all the bolts at torque of 1.10Kgf.m with torque wrench
3   Temperature variations between the cells   Avoid exposing batteries to external heat source which can cause temperature imbalance

Proper float operation at recommended individual cell voltage should be given within 2.25 0.05V.
When the voltage of the individual cell is lower than the normal, it is possible to conclude the insufficient charge has occurred.


As the temperature rises, electrochemical activity in the battery increases and as the temperature falls, the electrochemical activity decreases.

Increase capacity   Shortens life
Increase rate of discharge   Lowers the cell voltage
Increases rate of dry out    
Low temperatures (Lower than 27ºC) affects battery performance as follows.
Decrease the battery capacity   Increases battery life
Decreases rate of self discharge   Higher the cell voltage

If the battery operating temperature is something other than 27C (daily average temperature) it is desirable to modify the float voltages as follows.

Operating Temperature(0c) Float Voltage(v) Boost Charging Voltage(v)for maximum time of (12hr.) Charge Current(amps.)
0-9 2.35 2.40 0.25 C10
10-19 2.33 2.40 0.25 C10
20-29 2.30 2.40 0.25 C10
30-39 2.27 2.35 0.25 C10
40-49 2.25 2.35 0.25 C10
>50 Not Recommended Not Recommended Not Recommended

Temperature correction factors at various discharges

Corrections for variation of capacity with temperature to 27C shall be made in accordance with the formula given below. The capacity t 27C = {Ct + (Ct x R (27-t)}/ 100 Where: Ct = Obtained capacity at tC R = Variation factor chosen from the table given below. t = Average temperature in C

Discharge Rage Factor for variation capacity per 0C
C10 0.43
C8 0.47
C5 0.58
C4 0.62
C3 0.68
  Capacity / temperature correction is not a true liner relationship.
Requirement: The actual capacity corrected to 270C shall not
be less than 90% of the rated capacity at C10 rate of discharge.

Note: Temperature variation with in the battery string of more than 30c can cause cells to over or under charge.


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