Midac 2 MSP 55 User manual

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MSP
Vented Lead-Acid
STANDBY POWER BATTERIES
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Vented Lead-acid | StandBY POWeR BatteRieS 
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Standby batteries are generally used as back-up power, to support all those users who need a reliable service continuity
in case of black-out of the distribution network of electricity, hybrid and off-grid installations.
Lead-acid standby batteries are components of a system and they require the observance of suitable precautions and
behavioral norms to guarantee safe working conditions and to ensure the best performance of the battery during its entire
life. Scope of this document is to supply the necessary instructions for the correct cure, handling, installation, use and
maintenance of MIDAC MSP low maintenance Standby Power batteries.
Carefully read this manual in all its parts upon receipt of MIDAC MSP low maintenance standby batteries.
The non-compliance with the instructions given herein may cause injury to people and damages to the equipment, as well
as the bad operation of the battery.
Keep this manual in the battery room in a place easily accessible to the staff.
Observe the following precautions at all times. Batteries are no more dangerous than any other equipment when handled
correctly.
Batteries may give off explosive gasses.
They are lled with diluted sulphuric acid (electrolyte), which is a corrosive substance. When handling and working with
electrolyte always use protective equipment, such as protective clothing, rubber gloves and goggles. If acid is spilled on
the skin, wash immediately with copious amounts of clean water, then cover with dry gauze. If acid comes into contact
with the eyes, ush with clean water for at least 15 minutes. In all cases, obtain immediate medical attention.
Exposed metal parts of the battery always carry a voltage and are electrically live with the risk of short circuits.
Avoid any electrostatic charge; before starting your work on the battery, rst discharge any possible electricity from
yourself by touching an earth-connected part; repeat this action occasionally until the work is complete.

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Always take the following precautions:
• Keep batteries upright.
• Use insulated tools.
• DO NOT place or drop metal objects on top of the battery.
• DO NOT wear rings or bracelets. Remove any articles of clothing with metal parts that might come in contact with
the battery terminals.
• DO NOT smoke and DO NOT use open ames or create electric sparks.
• Take all precautions when using the main supply.
• Make sure that the rst aid kits and re extinguishers are easily accessible.
• Make sure that water and neutralizing products are easily accessible in case accidental contact with acid or spillage
occurs.
Used batteries contain recyclable materials. They must not be disposed with the house waste but as a special waste.
Methods of return and recycling must conform to the regulations in operation at the site where battery is located.
Unpack the batteries as soon as they are delivered.
Verify that the equipment has been delivered in good condition. Any damage must be reported immediately to the carrier
and the damaged items retained for inspection by the carrier’s representative.
For cells supplied in lled and charged conditions, check that the acid level in all the cells is at the “MAX” level. If neces-
sary, ll them in with diluted sulphuric acid with the correct specic gravity (see characteristics described under section 5).
If the battery cannot be immediately installed, store it in a dry, cool and clean place.
Do not expose the battery to direct sunlight, to avoid any damage to containers and lids.
Important Note! Storage time for lled and charged cells is limited. It is essential that they are placed on charge at the
latest within 90 days from the date of shipment. Failure to observe this condition may result in a greatly reduced capacity
and service life or in permanent damage to the cells.
The charge shall be carried out according to the instructions given under section 8.
Charge should be carried out with the shipping cases open, or the cells completely unpacked, and with adequate venti-
lation to disperse the gases formed on charging.
If continuous charging is not possible, the battery should be given a freshening or equalize charge at least every 60 days
and whenever distilled water is added.
If the battery is supplied in dry charged conditions, it can be stored for periods up to 3 years, provided that it is adequate-
ly protected against condensation and the effects of high humidity. For lling and commissioning of dry charged batteries,
see instructions given under sections 8.1 and 8.2.
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Vented Lead-acid | StandBY POWeR BatteRieS 

The following table gives specic gravity data at 25°C (77°F) for fully charged MSP low maintenance standby power
cells with the electrolyte at the maximum level:
Nominal Specic Gravity
(kg/l)
Specic Gravity Range
(kg/l)
Specic Gravity for
Filling Dry Charged Cells
(kg/l)
1,260 1,250 - 1,270 1,250
High quality electrolyte for standby lead-acid batteries (which is a solution of pure sulphuric acid diluted with distilled
water to the correct specic gravity) is required for the rst lling dry charged cells. If the electrolyte has been supplied by
MIDAC, store it in a safe place until required.
If electrolyte is purchased locally, make sure that its characteristics are in accordance with the following table:
Impurity Electrolyte for rst lling
(mg/l)
Electrolyte for relling
(mg/l)
Copper 0,5 0,5
Heavy metals (As, Bi, Sn, Sb) 2 6
Iron 30 100
Chlorine 5 200
Total azote 60 60
Organic substances 50 50
Other impurities 250 800
When electrolyte is sourced locally, we recommend an additional 10% spare is purchased to cover any loss or spillage
during handling and lling.
For quantity of electrolyte needed, please refer to cell technical data given under section 13. Always check the specic
gravity of the electrolyte before lling the cells. Minor adjustments may be made by adding water to lower the specic
gravity or by adding acid to raise the specic gravity.

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The battery room must be dry, clean and not subject to vibrations.
It must be properly sized to enable installation, inspection, topping up and maintenance. Also it must be duly ventilated,
especially during charge, and provided with explosion proof electrical equipment. Its temperature should be as moderate
as climate allows, preferably between 10°C (50°F) and 30°C (86°F). The battery will give its best performance when
working in a temperature of 20°C (68°F) - 25°C (77°F), but will be functioning even operating in temperatures between
-10°C (14°F) and 60°C (140°F). High temperatures increase the performance but reduce battery life, while low tempe-
ratures reduce the performance.
The entry doors of battery room must be provided with warning signs banning smoking, sparks and naked ames.
The batteries should be installed on suitable racks or shelves properly sized in loading capacity and dimensions. The
layout must enable easy access to all cells.
Racks or shelves can be made of wood or metal with acid-proof coating. If metal racks are used, they must be equipped
with rubber or plastic insulators to avoid any contact between the battery and the metal.
The rack location and ventilation system should be such that the maximum temperature differential between cells does not
exceed 3°C (5°F).
PAY SPECIAL ATTENTION TO BATTERY ROOM STANDARDS, EFFECTIVE AT THE MOMENT OF THE INSTALLATION
OF THE BATTERY.
Before installing the cells, clean and dry all parts. In particular: clean and dry lids and jars. Remove the protections from
the terminal posts and clean them with a soft clean cloth. In presence of spilled acid, dip a rag into a non-caustic alkali
solution (diluted ammonia or baking soda) and rub the posts body and the terminal inserts. If spilled acid is found into the
post inserts, soak the part with this solution and then dry. Do not let the solution get into the cells.
If the terminal posts surface is slightly white, lightly abrade it with a ne grit abrasive paper and remove oxidation. Do not
use a wire brush. Wipe off any dust and protect the post body to the lid with a thin coating of no-oxide grease.
Place the cells on the rack and make sure that the spacing allows the accommodation of the supplied inter-cell connectors
(around 10 mm between the cells). Most batteries have cells connected in a simple series arrangement, so the cells should
be arranged to preserve the sequence: positive (+), negative (-), positive (+), negative (-) throughout the whole battery.
Cells supplied in dry charged conditions must be lled-in with electrolyte after installation on battery racks.
WARNING
NEVER LIFT CELLS BY THE TERMINAL POSTS. ALWAYS USE APPROPRIATED DEVICES (SUCH AS LIFTING STRAPS AND
SUITABLE MECHANICAL LIFTING DEVICES) TO PREVENT INJURY TO PERSONNEL OR DAMAGE TO THE CELLS.
For batteries to be installed on multiple tiers, start by placing the cells on the lower tier on either side of the frame where
the stand sections meet. Any unused stand space should be on the upper tier.
For batteries on stepped racks, leave any unused space on the back (top) step.
Where multiple racks are arranged end-to-end, adjust the position of the adjacent end cells to accommodate the exible
inter-rack connectors supplied.
Take particular care to preserve the positive to negative sequence when using exible inter-tier, inter-step or inter-rack
connectors between rows of cells. Leave the main positive and negative terminals of the battery free for connection to the
charging source.
Check cell alignment.

Vented Lead-acid | StandBY POWeR BatteRieS 
Prepare the inter-cell connectors by cleaning up the contact surfaces. Do not use a wire brush and be especially careful
not to break through the insulation.
Apply a light coating of no-oxide grease to the contact-making areas of each connector.
Fit the inter-cell and inter-tier connectors using the bolts, nuts and washers supplied. Before assembly, lightly smear no-
oxide grease on the surfaces of all hardware.
Use only insulated wrenches to tighten the parts rmly together, with torque setting of 15 to 20 Nm (133 to 177 in lbs).
Pay special attention to avoid short-circuiting the cells with any of the battery hardware.
Check tightness and cleanliness.
Make sure that all vent caps are closed.
Connect the positive terminal of the battery to the positive terminal of the charger and the battery negative to the charger
negative.
Number the cells by using the set of numbering stickers supplied with the battery. It is common practice to number the
cells beginning with #1 at the positive end of the battery and following the sequence of electrical connection of the cells,
through to the negative end of the battery.

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8.1 Filling of dry charged cells
Always use glass or plastic jugs and funnels to ll the cells. Never use metallic materials; electrolyte may corrode them or
react by contact. Fill the cells to reach the “MAX” line level and wait to allow the acid soak into separators and plates.
This operation should take approx. 3 hours; then, due to absorption, the electrolyte level will drop allowing topping up
to the “MAX” level line.
The quantity of electrolyte required to ll each cell is given in section 13.
Always ll the cells with electrolyte after installation on battery racks.
NOTE
CELLS FILLED ON SITE MUST BE GIVEN AN INITIAL CHARGE AS SOON AS POSSIBLE. DO NOT STORE FILLED CELLS
FOR MORE THAN 18 HOURS WITHOUT CHARGING THEM.
8.2 First charge of dry charged cells
An initial or freshening charge must be given to all batteries before being put into service. This is most important for cells
supplied in dry charged conditions and lled on site.
Before starting the charge, check that electrolyte temperature does not exceed 35°C (95°F). If necessary let the battery
rest until this temperature is reached. Take individual cell readings of voltage, specic gravity and temperature before
starting initial charge. It is advisable to use a constant voltage charger, with constant adjustable voltage from 2.22 to
2.60 Vpc and with an available adjustable current from 0 to 0.20 C10 Amps.
If the charger does not allow any current adjustment, the max. current should not exceed 0.10 C10 Amps.
Charge the battery with a current rate of 0.10 C10 Amps for approx. 16 hours.
During this operation take voltage and specic gravity readings every 3 hours.
Voltage readings must be taken on every cell; specic gravity readings can be taken on designate pilot cells (for example
one out of ve).
Monitor also electrolyte temperature (select 2 or 3 pilot cells).
Should the temperature exceed 45°C (113°F) then:
- decrease the charging current to a lower rate (50%)
or
- discontinue the charge and let the battery stand on open circuit until the temperature falls down to 35°C (95°F); after
that, the charging process can be resumed. In this case, please consider the charging time to be extended proportionally.
At the end of this process, the Ah delivered to the battery must be 1.5 ÷ 1.6 times the C10 rated capacity.
Charging is to be deemed as completed when:
- the specic gravity readings in the cells have reached the nominal specic gravity of 1,260 kg/l ± 0.01 corrected at
25°C (77°F);
- the cell voltage is equal or greater than 2.60 Vpc;
- both above values (voltage per cell and specic gravity) remain constant for at least two or more hours under charge.
If the charger characteristics do not allow to reach 2.60 Vpc, the charging time shall be extended in order to deliver to
the battery at least 1.5 ÷ 1.6 times the nominal Ah capacity. In any case a minimum constant voltage of 2.40 Vpc should
be available for rst charge process.

Vented Lead-acid | StandBY POWeR BatteRieS 
8.3 Filled and charged cells (Freshening Charge)
For batteries which have been supplied in a lled and charged condition, it is normal to lose charge while in transit or du-
ring storage. For this reason, a freshening charge should be given before putting the battery into service. This is normally
accomplished using the “equalize” voltage setting on the charger (see section 8.4.3).
A lower charging voltage (down to a minimum of 2.33 Vpc) may be used, but this will extend the duration of the initial
charge to as much as 100 hours.
The initial charge may be terminated when the specic gravity readings of all cells have remained constant for at least
2 hours.
At the end of this initial charge, set the battery voltage to the MIDAC recommended oat voltage (see section 8.4.1).
8.4 Charging in service
Temperature compensation must be as follows:
±3.5 mV each °C out of the range 20°C / 25°C
- from 20°C to 25°C: no need of temperature compensation
- below 20°C (68°F): voltage +0.0035 V/°C
- above 25°C (77°F): voltage -0.0035 V/°C
Once put into service, MIDAC MSP low maintenance Standby Power batteries should be charged as follows:
8.4.1 Float charge at constant voltage
To maintain the battery in fully charged condition during normal battery operation or, after a discharge, to recover 90%
of nominal capacity within 20 hours, a recommended oat charge has to be applied.
Recommended oat voltage settings are as follows:
Constant voltage 2.22 ÷ 2.23 Vpc with electrolyte SG 1.260 ± 0.01 kg/l at 25°C (77°F)
(Current limitation 0.10 C10 Amps)
With the method described above, the effective charging current is limited to very low values; such current increases as a
function of temperature and age of the battery. Gassing and water consumption are also minimized.
To verify the charge efciency of the battery, the constant control of the electrolyte specic gravity and temperature is
essential.
Decreasing of specic gravity is symptom of insufcient charge.
Increasing of specic gravity and decreasing of electrolyte level are indication of excessive charge.
For comparison of electrolyte specic gravity vs. temperature, refer to section 9.

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8.4.2 Equalizing charge
Chargers have usually two adjustable charging voltages: one for the “oating” charge and one for the “equalizing”
charge (also known as “boost”, “high rate” or “recharge”).
The equalizing charge is generally required:
- when the total voltage spread between the cells is greater than 0.04 V under oat charging conditions;
- for fast recharging after a discharge;
- after addition of distilled water to assist in mixing the acid and water;
- for oat charge using voltages below 2.23 Vpc (see table below)
- for oat charge using voltages below 2.22 Vpc (see table below)
Float Vpc Equalizing Required at these Intervals
2.25 Never
2.23 Every 3 Months
2.20 Every Month
2.17 Twice a Month
Equalizing may be carried out at voltage settings above 2.30 Vpc.
Recommended equalize voltage settings are as follows:
Constant voltage 2.35 ÷ 2.45 Vpc with electrolyte SG 1.260 ± 0.01 kg/l at 25°C (77°F)
(Current limitation 0.15 C10 Amps)
The length of equalize charging required will depend on the depth of discharge, electrolyte temperature and normal oat
voltage level. The best guideline is to continue equalizing until the specic gravity of the acid in the designate pilot cells
has been constant for at least 2 hours.
8.4.3 IU charge
The IU charge is normally used for fast recharging or in cycling use.
IU charge consists of two phases:
- 1st phase: constant current – recommended rate: 0.20 C10 (A). The voltage increases up to the limited voltage of 2.40 Vpc;
- 2nd phase: constant voltage of 2.40 Vpc. The absorbed current decreases. Once the current has reached a low and
constant value (approx. 0.03 A per Ah) the charge continues in oating.