First National Battery RAYLITE M-SOLAR User manual

RAYLITE M-SOLAR
BATTERIES
INSTALLATION AND
MAINTENANCE INSTRUCTIONS

SAFETY WARNINGS
NO CHILDREN. Children must be kept away from batteries at all times.
EXPLOSION HAZARD, NO SMOKING, NO
NAKED FLAMES. Batteries generate highly explosive gasses during charge.
No smoking, sparks or any form of naked flame is to be allowed near the battery at
any time. Assume that there is explosive gas present above the cells at all times.
Keep the battery tops clear from all conductive objects that may cause a spark. Use
an insulated torque wrench when assembling the battery. To avoid electrostatic
build-up use a damp cloth when cleaning cells. In order to prevent electrical tracking
between cells keep the cell tops clean and mop up any spillage.
ELECTRIC SHOCK. The battery remains live at all times, even if
isolated and discharged. The threshold voltage for fatal electric shock is lower with
Direct Current than with alternating Current.
CORROSIVE ACID. Battery electrolyte contains dilute sulphuric acid.
This is highly corrosive and can cause severe skin burns. If spilt or splashed onto
skin or clothing, neutralise with a solution of baking powder and water. If splashed
into the eyes wash for at least 15 minutes with copious amounts of water and consult
a doctor as soon as possible.
PROTECTIVE CLOTHING. Wear eye protection (goggles or face
mask) and rubber gloves when working on the battery. An acid resistant (rubber or
plastic) apron and thick rubber soled shoes are also recommended.

SIZING OF M-SOLAR INSTALLATIONS
It is recommended that the battery be sized to limit the daily depth of discharge to
20% of the 100-hour rate capacity. This caters for up to 5 days of cloudy weather
whilst giving optimum life expectancy.
The daily consumption can be calculated by taking each electrical item’s wattage
and estimating the maximum time in hours that it is likely to run each day. The
product of these two figures will give the Watt-hour consumption each day. Totaling
the result for each item will give the system consumption per day. Alternatively many
web sites give the expected consumption for household appliances.
The total daily Watt-hour consumption divided by the overall nominal battery voltage
will give the Ampere-hours required each day. Multiplying this by 5 will indicate the
size of battery required.
The solar array must be able to deliver sufficient power to supply the load and
recharge the battery on an average day of irradiation plus have reasonable excess to
cater for the recharge over a few days when the battery is more deeply discharged
due to consecutive days of poor weather.
PREPARING THE BATTERY FOR SERVICE
UNPACKING
Clean off any packing material from the cells and trays. Examine carefully to see if
there has been any damage in transit.
Check that all components have been supplied.
Cells may be supplied loose or pre-assembled in 4 volt (2 cell) or 6 volt (3cell)
trays. If in trays, inter-tray cables and two take-off cables will be supplied. If
loose cells, inter-cell cables and two take-off cables are supplied.
One electrolyte level indicator per cell.
One Installation and Maintenance Manual (this document).
One battery log book.
One hydrometer.
Important: Any damage or shortages must be reported to the carrier and First
National Battery must be notified.
PREPARING THE CELLS
•Open all vent filler plugs and examine the electrolyte levels in all cells.
•Check all specific gravities (25°C).
•Batteries can be put into service immediately, provided the specific gravities are
above 1.240 (25°C) and electrolyte levels are correct.
If the specific gravities are below 1.240 it is necessary to give the battery an
equalizing charge. This consists of charging at a constant current of 2.5% to 5% of

the C100 capacity until the voltages and specific gravities have remained constant
over 3 x 1 hourly readings.
If the battery is not required immediately for service, it should be stored under roof in
a cool, clean, dry and well-ventilated area. Where connection has not been made to
the cell terminals, remove the covers, wipe the terminals clean and apply a thin layer
of Vaseline to the outer surface. Replace the terminal covers. Equalize charge at
three monthly intervals or whenever the cell voltage drops below 2.05Vpc (Volts per
cell) or the specific gravity drops below 1.210. The electrolyte levels should be
adjusted as required by topping up with approved water.
WIRING STANDARDS
Comply with all local regulations concerning codes of practice that apply to
electrical/battery installations.
BATTERY ASSEMBLY
If the cells have been supplied loose assemble the battery in the container/s. If (for
whatsoever reason) cells are not in plastic moulded trays or steel tanks, it is
essential that cells be strapped together so as to support the internal plates of the
cells while in operation. This should be done as follows.
1 Wooden boards ≥18mm thick should be used as support when strapping the
cells.
2 Note: In all cases, the wooden boards must be fitted against the 158mm
width face of the cells / or 198mm in case of DIN cells. See Figure 3 below.
3 It is not necessary to place boards against the length of the cells.
4 It is not recommended to strap more than 2 rows of cells together as this can
potentially reduce the support on the ends of the rows as well as prevent
adequate air cooling to the cells.
5 Cell packing spacers must be placed between cells. A minimum of at least
one spacer should be used to separate four strapped cells.
6 Note: Fitting spacers between each cell will give the cells a better chance of
working cooler in operation, which is beneficial to the life of the cell.
7 Cells must be firmly strapped, reducing any bulging of the cells on the
supported ends.
8 Do not over tighten the strapping. The walls of the cell container must be
perpendicular and square and not bow inwardly or push inwardly due to over
tightening of the support boards.

9 Caution: strapping the cells will cause acid levels inside the cells to rise,
especially with taller cells. If the electrolyte levels rise above maximum, any
surplus acid should be removed.
10 It is important to support the cell adequately across the full height of the cell.
Depending on the cell height, 2 to 3 ratchet tie down should be used.
11 Failure to provide this support will nullify any warranty.
Where connectors have not yet been fitted remove the bolts, wipe the terminals
clean and apply a light coating of Vaseline to the outer surface of the terminal.
Connect the cells together using the inter-connectors provided ensuring that the cells
are connected negative to positive throughout. When numbering the cells always
begin at the positive end as cell number 1.
Connect the take-off cables one at a time, terminating both ends of the first cable
before connecting the second. When connecting the second take-off connect at the
battery first before connecting to the charger side. This minimises the chance of
creating a spark close to the battery.
Fit the float level indicators. Check that the indicators move freely and are at the ‘full’
level. If the levels are low do not top up until the battery has been fully charged.
COMMISSIONING
Switch on the solar array. Check that all regulator settings are correct (see Solar
System Set Points). Allow the battery to be fully charged before applying any loads.
When fully charged take and record temperature corrected individual specific gravity
and cell voltage plus pilot electrolyte temperature readings (see Temperature
Correction of Specific Gravities). These readings provide a base that can be referred
to when assessing the condition of individual cells during the battery life.

SOLAR SYSTEM SET POINTS
Whilst there can never be hard and fast set points for a solar system due to
variations in operating modes the following data is given as a guide.
Normal recharge maximum voltage: 2.45Vpc
Absorption time: 3 to 4 hours
Float voltage: 2.27Vpc
Equalisation voltage: 2.60Vpcl
Equalisation interval: 20 days
Duration of equalise charge: 2 hours
Low voltage cut-off (100% DOD) 1.85Vpc*
Temperature compensation coefficient: 2mVpc per OC
* Based on the assumption that the system has been designed to give 3/5 days
autonomy and that recharge will be commenced within 48 hours of reaching fully
discharged condition.
In addition we recommend that batteries be fully equalised when individual cells
become out of step. This condition is present when:
(i) The end of charge voltages of individual cells differ by more than 0.10 Volt
from the lowest to the highest voltage.
(ii) The specific gravities at completion of charge vary by more than 0.030 or
do not rise to within 0.030 of the normal recommended top of charge
value.
Equalising implies charging at approximately 3.5% of the 100 hour capacity. At this
rate of charge, voltages of 2.60 to 2.75Vpc should be achieved (when new at
temperatures of 20/25 degrees C), the voltage will be lower at higher temperatures
and as the battery ages). If the solar panels do not have the power necessary for
equalising, other means, such as a generator should be provided. Equalisation is
regarded as complete when there is no rise in voltages or specific gravities over
three one hourly readings.
The PV array should be sufficient to supply the daytime load while maintaining the
battery in a charged state on days of average irradiation plus have reasonable
excess to cater for the recharge over a few days when the battery is more deeply
discharged due to consecutive days of poor weather.

BATTERY OPERATION
DISCHARGE
Immediately after the solar array output falls below that being consumed by the load
the battery begins supplying the load. This will initially result in a rapid fall in voltage.
Assuming the battery was on float charge at 2.27Vpc it will drop to the open circuit
voltage of about 2.12Vpc even if there is no load. Depending on what the actual load
is at the time it is possible that the voltage could drop to around 2.00Vpc. After this
the voltage will stabilise and only drop slowly over time. Assuming the battery has
been sized to give 3 to 5 days autonomy it is permissible to fully discharge on those
rare occasions to 1.85Vpc.
Whilst discharging, acid is absorbed by the plates and the specific gravity drops in
proportion to the depth of discharge. From a fully charged condition the specific
gravity will drop from 1.280 to approximately 1.100.
The life of the battery is very dependent on the depth of discharge (DOD) that it is
subjected to on a daily basis. When used in a purely standby application where there
are virtually no discharges the expected life is 10 to 12 years. When cycling it would
be unrealistic to expect any longer life than that achieved on float, therefore the
maximum life to be expected would be 4380 cycles (i.e. 365 cycles x 12 years).
From the graph below it can be seen that this would be attained if the battery had a
daily 20% DOD. The occasional deeper discharges would have marginal effect on
the life to be expected.
1.100
1.120
1.140
1.160
1.180
1.200
1.220
1.240
1.260
1.280
1.300
100 90 80 70 60 50 40 30 20 10 0
SPECIFIC GRAVITY
STATE OF CHARGE (%)
SPECIFIC GRAVITY Vs STATE OF CHARGE OF M-SOLAR CELLS

RECHARGE
The normal method of solar charging is to charge at the current available from the
solar array up to a maximum of 30%C100Amps until the battery voltage reaches
2.40/2.45Vpc. This period is referred to as the ‘bulk charge’. The regulator then
controls the charge voltage at 2.40/2.45Vpc for a set period of 2 to 4 hours. This is
termed ‘absorption time’. The charge then reverts to the ‘float charge’at 2.27Vpc.
During this charge, acid is released from the plates and because it is heavier than
the surrounding electrolyte it sinks to the bottom of the cell.
With the above charging regime the battery may receive sufficient charge on a good
irradiation day to fully convert the active materials but, because there is no vigorous
gassing of the electrolyte, the acid that has been released from the plates remains at
the bottom of the cell. This results in weak acid at the top of the cell and strong acid
at the bottom. This is called stratification and can cause deterioration of the plates.
To prevent stratification damage it is recommended that the battery be given an
equalisation charge every 20 days. This mixes the electrolyte and brings weaker
cells into line with those that are stronger.
Initially, top of charge specific gravities should be in the range 1.250 to 1.270 but
these may rise above 1.270 over the first few weeks of operation. This is normal and
is not detrimental to the performance of the battery. However if the specific gravities
rise above 1.300 they should be adjusted downward (see Adjustment of Electrolyte
Specific Gravity).
0
500
1000
1500
2000
2500
3000
3500
4000
4500
5000
010 20 30 40 50 60 70 80 90 100
NUMBER OF CYCLES
DEPTH OF DISCHARGE (AS % OF 100 HOUR CAPACITY)
EXPECTED CYCLE LIFE Vs DAILY DEPTH OF DISCHARGE

TEMPERATURE
The operating temperature of the battery affects the capacity available and the life of
the battery.
When temperatures are higher than the nominal 25oC the capacity increases and at
lower temperature, decreases. However, increases in temperature can drastically
reduce the expected life. A 10oC increase in the average operating temperature can
reduce the life of the battery by 50%.
It is therefore important to install the battery in as cool an area as possible and to
provide good ventilation.
BATTERY MAINTENANCE
The maintenance of the battery is a major factor in the service life achieved. It is
therefore important that the following instructions are followed.
WEEKLY
Check to ensure the charging system is operating within specified limits and
reset if necessary.
Check that the level indicators move freely and that the electrolyte levels are
between the full and low marks. If levels are low, top up with distilled or
deionised water (see Specification for Purity of Topping-up Water) .
Inspect the cells for any apparent signs of failure or problems requiring
immediate repair.
Clean the cell lids with a damp cloth.
MONTHLY
As weekly plus:-
Apply equalising charge.
At the end of the equalise charging period measure and record the cell
voltages, corrected specific gravities and pilot cell electrolyte temperature in
the log book provided.
At end of night discharge period measure and record the cell voltages,
corrected specific gravities and pilot cell electrolyte temperature in the log
book provided.
Check for signs of loose connections and re-tighten where necessary.

SPECIFIC GRAVITY MEASUREMENT
DETERMINING THE STATE OF CHARGE OF THE BATTERY
Dilution of the electrolyte during discharge is a useful guide to the state of charge of
a lead acid cell. The less acid there is in the electrolyte, the less dense it is, and the
lower its specific gravity. One cubic centimetre of water has a mass of 1 gram. In
other words, its density is 1 gram per cm3 at 4°C. Specific gravity is the ratio of the
density of the substance measured to the density of water. The density of water at
4°C is 1.000 g/cm3. The specific gravity of water is therefore usually expressed as
1.000.
Density could also be expressed as the mass of the liquid divided by the mass of an
equal volume of water.
Specific gravities are usually measured with a hydrometer. This works on the
principle that a float will sink further into a liquid of low specific gravity than of high
specific gravity because the latter is denser and provides greater support.
USING THE HYDROMETER
From one of the cells, draw acid into the barrel until the hydrometer float moves
freely. Now read the specific gravity at the point where the scale emerges from the
acid. Afterwards, make sure the acid is returned to the cell from which it was drawn,
or the specific gravity and acid level of both cells will be altered.
When taking a reading
• Make sure that there are no air bubbles under the float.
• Bring your eye level with the acid surface in the barrel of the hydrometer.
• Ensure that the hydrometer is in a vertical position.
• If necessary, shake the hydrometer gently to enable the float to move freely.
• If the ambient temperature differs from the battery temperature, draw in electrolyte
to warm the hydrometer first.
• Read off against the lower meniscus.

Wash the hydrometer barrel and float with soap and water on a regular basis. Rinse
thoroughly with water after washing to prevent soap transfer to the battery
electrolyte.
The change in specific gravity of the acid is directly proportional to the ampere hours
taken out of the cell on discharge.
The minimum recommended specific gravity is 1.140. Select a different pilot cell
each month to serve as a useful, general indicator of the condition of the battery
during charge and discharge.
Note: The specific gravity of a cell will decrease with any increase in temperature.
Always record the electrolyte temperature when specific gravity readings are taken.
TEMPERATURE CORRECTION OF SPECIFIC GRAVITIES
All specific gravities quoted relate to temperature at 25oC and have to be corrected if
read at other electrolyte temperatures.
Specific gravities decrease as the temperature increases. To provide a standard, the
specific gravity can be corrected to 25oC in the following manner:
Take the temperature of the electrolyte and
• add 7 points (0.007) to the specific gravity reading for every 10oC above 25oC or
• subtract 7 points (0.007) from the specific gravity reading for every 10oC below
25oC.
For example:
A reading of 1.255 at 35oC corrected to 25oC gives 1.255 + 0.007 = 1.262
or
A reading of 1.275 at 15oC corrected to 25oC gives 1.275 - 0.007 = 1.268
ADJUSTMENT OF ELECTROLYTE SPECIFIC GRAVITY
Charge the battery at the equalising rate until specific gravities have been constant
over three successive readings taken at hourly intervals.
Should the specific gravity be high, remove a little of the electrolyte and replace
with an equal volume of distilled or deionised water. Add a small amount at a time,
forcing it well down into the cell, with the cells gassing, to help mix the water with the
acid. Allow the electrolyte to thoroughly mix by leaving on a vigorous gassing charge
for at least 1 hour. When mixed, read the specific gravity. Repeat this process until
the specific gravity is within the specified tolerance.
It is essential that the battery has been on charge at a voltage high enough to cause
vigorous gassing over 3 hours with no increase in specific gravity before attempting
to adjust the specific gravity upwards. If in doubt First National Battery should be
contacted for advice. When these conditions have been met and specific gravity is
still low remove a little of the electrolyte and replace with an equal volume of stronger
sulphuric acid (e.g. 1.400) while agitating as described above. Once again, repeat
the process until the specified tolerance is achieved.
When the adjustment has been completed, ensure that the level of the electrolyte in
each cell is correct by removing excess acid or topping up to the correct level with
acid of the same specific gravity.

BATTERY WATER
Water used for topping up batteries must comply with the following specifications:
• It shall be clear, colourless and odourless.
• The pH shall be between 5 and 7.
• Impurities shall not exceed the limits below.
• It shall, wherever possible, be stored in a glass or plastic container.
• Conductivity shall be less than 30 μS/cm
IMPURITY
MILLIGRAMS
PER LITRE
DISSOLVED SOLIDS
25
ARSENIC (As)
1
CHLORIDE (Cl)
5
COPPER (Cu)
0.1
IRON (Fe)
0.2
MANGANESE (Mn)
0.1
NITROGEN (as NH4)
5
NITROGEN (as NO3)
5
HEAVY METALS (as Pb)
5
KMn04 REDUCING SUBSTANCES*
10
*As determined by F.N.B. test method LTM - 31 -01
TROUBLE SHOOTING
The following notes are provided to assist in identifying symptoms and causes of
possible system problems.
SYMPTOMS CAUSES SOLUTIONS
Low or irregular voltages Undercharge. Faulty Reset regulator
and/or specific gravity. regulator settings. settings.
.
Battery requires Apply equalise charge.
equalise charge.
Undercharge. Install more panels or
Insufficient solar reduce load.
panels to recharge.
Overdischarge. System Reduce load or
undersized for the load. increase capacity.
Faulty cell/s. Replace cell/s unless
battery is near end of
life.

Battery reaching end Replace battery.
of life.
Battery fails to supply load. Undercharge. See above.
Overdischarge. System Reduce load or
undersized for the load. increase capacity.
Faulty cell/s. Replace cell/s unless
battery is near end of
life.
Battery reaching end Replace battery.
of life.
High operating temperatures. Overcharge. Faulty Reset regulator
regulator settings. settings.
Poor ventilation or Improve ventilation,
batteries in sun. re-site to shade.
Excessive water consumption. On one cell, suspect Confirm and re[lace.
leaking cell container or
faulty cell.
On complete battery. Reset regulator
overcharge. settings. Reduce
equalise charge.
Growth of positive post. Early in life: overcharge. Reset regulator
settings. Reduce
equalise charge.
Towards expected end Budget for.
of life normal. Indication replacement
that failure may occur
soon.
August 2017