Samlexpower MSK-10A User manual

Solar
Charge
Controller
MSK-10A
Please read this
manual BEFORE
using your
Charge
Controller
Owner's
Manual

2 | SAMLEX AMERICA INC.
OWNER'S MANUAL | Index
SECTION 1
Safety Instructions................................................................. 3
SECTION 2
General Information, Features & Layout ............................... 5
SECTION 3
Installation ........................................................................... 7
SECTION 4
Operation ........................................................................ 13
SECTION 5
Protections & Troubleshooting ........................................... 22
SECTION 6
Specications ...................................................................... 26
SECTION 7
Warranty ........................................................................ 28

2 | SAMLEX AMERICA INC. SAMLEX AMERICA INC. | 3
SECTION 1 | Safety Instructions
IMPORTANT SAFETY INSTRUCTIONS
PLEASE READ THE FOLLOWING SAFETY INSTRUCTIONS BEFORE USING THE CHARGE CONTROLLER.
FAILURE TO ABIDE BY THE RECOMMENDATIONS MAY CAUSE PERSONAL INJURY / DAMAGE TO THE
CONTROLLER.
The following safety symbols will be used in this manual to highlight safety
and information:
WARNING!
Indicates possibility of physical harm to the user in case of non-compliance.
!CAUTION!
Indicates possibility of damage to the equipment in case of non-compliance.
i
INFO
Indicates useful supplemental information.
WARNINGS !CAUTIONS!
1. This Charge Controller is not waterproof (Ingress Protection Rating is IP-30). PLEASE
ENSURE THAT THE UNIT IS INSTALLED IN DRY, COOL AND WELL VENTILATED ENVI-
RONMENT.
2. Ground the Negative of the battery as follows:
• to Earth Ground in shore installations
• to Chassis Ground in Negative grounded mobile installations
3. There are no user serviceable parts inside the controller. Do not disassemble or
attempt to repair it.
4. Install external fuses / breakers as required.
5. Disconnect the PV Panel(s) and fuse / breakers near to battery before installing or
adjusting the controller.
6. Conrm that power connections are tightened to avoid excessive heating from
loose connection.
7. The charge controller has been set to optimally charge 12V / 24V Lead Acid
Batteries (Sealed/AGM)
8. Comply with battery manufacturer’s recommendations.
9. Avoid charging damaged, defective or old battery.
10. Ensure correct polarity is maintained when connecting the Charge Controller to the
battery - Connect the Positive output terminal to the Positive Battery Post and the
Negative output terminal to the Negative Battery Post.
11. When charging, removal of the battery from the vehicle is not necessary provided
the battery is being charged in a well-ventilated area.

4 | SAMLEX AMERICA INC.
SECTION 1 | Safety Instructions
12. Batteries contain very corrosive diluted Sulphuric Acid as electrolyte. Precautions
should be taken to prevent contact with skin, eyes or clothing. If battery acid
makes contact with skin or clothing, ush immediately with water. See a doctor
immediately.
13. Batteries generate Hydrogen and Oxygen during charging resulting in evolution of
explosive gas mixture in non-sealed batteries. Care should be taken to ventilate the
battery area when non-sealed batteries are used and follow battery manufacturer’s
recommendations.
14. Ensure there are no ammable substances, explosive gases, ames, smoke or spark
near the battery or the PV Panel(s).
15. Use caution to reduce the risk of dropping a metal tool on the battery. It could
spark or short circuit the battery or other electrical parts and could cause an
explosion.
16. Remove metal items like rings, bracelets and watches when working with batteries.
Batteries can produce a short circuit current high enough to weld a ring or the like
to metal and thus cause a severe burn.
17. If you need to remove a battery, always remove the ground terminal from the bat-
tery rst. Make sure that all the accessories are off so that you do not cause a spark.
18. PV Panel(s) generate electrical power when exposed to sunlight. Place a dark cover
over the panels when handling panels that have bare, un-insulated output wires.
Accidental shorting of panel terminals or wiring connected to the panels can result
in spark causing personal injury or a re hazard.
19. It is important that the battery gets fully charged frequently (at least once per
week). Otherwise, the battery can become permanently damaged due to under
charging. Partially charged batteries can quickly sulfate internally which is an ir-
reversible condition. It is good practice to prevent a battery from being discharged
below 50%. Deeper discharging severely shortens battery life.
20. Keep the surface of PV Panel(s) clean from dust. Clean with a soft cloth. Do not
walk on the panels.
21. Installation and wiring must comply with the local and National Electrical Codes
and must be done by a certied electrician.

4 | SAMLEX AMERICA INC. SAMLEX AMERICA INC. | 5
SECTION 2 | General Information, Features
& Layout
2.1 GENERAL INFORMATION
MSK-10A is a 10A rated, Series Type of PWM (Pulse Width Modulation) Charge Control-
ler. It is based on an advanced design using a microcontroller for digital accuracy and
fully automatic operation. It can be used for 12V or 24V battery systems.
2.2 FEATURES
- Advanced microcontroller based, high performance design for digital accuracy and fully
automatic and intelligent operation
- Series Type PWM (Pulse Width Modulation) charging for low loss, higher efciency
charging and longer battery life
- Up to 50V Open Circuit Voltage (Voc) and up to 10A Short Circuit Current (Isc) of PV
Panel(s) - enables use of up to 150W of 12V Nominal panels for 12V battery and up to
300W, 24V Nominal panels for 24V Nominal battery.
- Dual voltage capability – can be used with 12V / 24V Nominal PV Panel(s) / batteries. 12V /
24V Nominal Battery System is detected automatically: Battery voltage < 18V is detected as
12V Nominal battery and >18V is detected as 24V Nominal battery
- 4 stages of charging for 100% return of capacity and for longer battery life
• Normal: Bulk Stage gAbsorption Stage gFloat Stage
• Once every 28 days or, if battery voltage drops to 11.1/22.2V: Bulk Stage gEqualization
Stage gFloat Stage
- Set for charging sealed/AGM Lead Acid Battery
- User friendly LED display for monitoring of operation and self diagnostics for
troubleshooting
- Integrated or optional external Temperature Sensor for temperature compensation to
ensure improved charging of batteries that experience wider temperature variations
during the year
- MOSFET based reverse current blocking for night-time battery discharge prevention. This
allows much lower losses as compared to Diode based blocking
- Protections: (i) PV over current (ii) PV short circuit (iii) PV reverse polarity (iv) PV over
voltage (v) High voltage transients on PV input (vi) Battery reverse polarity (vii) Battery
over voltage (viii) Battery over discharge (ix) Controller / battery overtemperature (x) Over
voltage, overload and short circuit protections on Load Terminals
2.3 APPLICATIONS
- Recreational / Service Vehicles
- Off grid
- Portable Charging Kits
- Boats and marine crafts
- Field work / mobile ofces
- Telecommunications

6 | SAMLEX AMERICA INC.
2.4 LAYOUT
LEGEND FOR FIG 2.1
Item No. Description Item No. Description
1 PV Status LED 6A Battery Terminal (+)
2 Battery Status LED 6B Battery Terminal (–)
3 Load Status LED 7A Load Terminal (+)
4 Load On/Off Button
Also used for clearing fault 7B Load Terminal (–)
5A PV Input Terminal (+) 8 *Connector for optional remote
battery temperature sensor
"MSK-TS"
5B PV Input Terminal (–) 9 RS-485 Communication Port
(NOT USED)
* If the temperature sensor is short-circuited or damaged, the controller will charge or
discharge at the default temperature setting of 25°C.
SECTION 2 | General Information, Features
& Layout
1 2 3
4
5A
5A
5B
5B
6A
6A
6B
6B
7A
7A
7B
7B
98
Fig 2.1: Layout of Charge Controller MSK-10A

6 | SAMLEX AMERICA INC. SAMLEX AMERICA INC. | 7
SECTION 3 | Installation
3.1 SAFETY
WARNING! !CAUTION!
PLEASE READ ALL THE SAFETY INSTRUCTIONS GIVEN IN SECTION 1 BEFORE
INSTALLING AND OPERATING THE CONTROLLER. FAILURE TO ABIDE BY THE
RECOMMENDATIONS MAY CAUSE PERSONAL INJURY / DAMAGE TO THE KIT.
DO NOT USE THE UNIT IN WET ENVIRONMENT
• Please note that this unit is not waterproof (its Ingress Protection Rating is
IP-30). Hence, please ensure that the unit is installed in dry environment.
GROUNDING
• Ground the Negative terminal of the battery to Earth Ground in shore
installation and to the Chassis Ground in Negative grounded mobile
installations.
BATTERY TYPES
• The unit has been set to optimally charge 12/24V, sealed (AGM) Lead Acid
Batteries
MISE EN GARDE! !ATTENTION!
VEUILLEZ LIRE TOUTES LES INSTRUCTIONS DE SÉCURITÉ DONNÉES DANS LA
SECTION 1 AVANT D'INSTALLER ET D'UTILISER LE CONTRÔLEUR. NON-RESPECT
DE LA LES RECOMMANDATIONS PEUVENT PROVOQUER DES BLESSURES OU
ENDOMMAGER LE KIT.
N'UTILISEZ PAS L'APPAREIL DANS UN ENVIRONNEMENT HUMIDE
• Veuillez noter que cet appareil n'est pas étanche (son indice de protection
d'entrée est ip-30). Par conséquent, veuillez vous assurer que l'unité est installée
dans un environnement sec.
MISE À LA TERRE
• Mettez à la terre la borne négative de la batterie à la terre à la terre dans
l'installation à terre et à la masse du châssis dans les installations mobiles à la
terre négative.
TYPES DE BATTERIE
• L'unité a été réglée pour charger de manière optimale des batteries au plomb
scellées (AGM) de 12/24V

8 | SAMLEX AMERICA INC.
SECTION 3 | Installation
3.2 DIMENSIONAL DRAWING
Dimensional drawing is given at Fig 3.1 below:
126
+ – + – + –
Height: 37
NOTE: All dimensions are in mm
69.3
6
138.6
Mounting Hole: 4.3 mm
Terminals: 4 mm2
4.3
34.65
Fig 3.1: Dimensional Drawing of Charge Controller MSK-10A
3.3 MOUNTING
Refer to Fig 3.2
When mounting the controller, ensure free air through the ventilation slots at the
bottom of the unit. There should be at least 6 inches (150 mm) of clearance above
and below the controller to allow for cooling. If mounted in an enclosure, forced air
ventilation is highly recommended.
WARNING!
RISK OF EXPLOSION! NEVER INSTALL THE CONTROLLER IN A SEALED ENCLO-
SURE WITH FLOODED BATTERIES! DO NOT INSTALL IN A CONFINED AREA
WHERE BATTERY GASSES CAN ACCUMULATE.
MISE EN GARDE!
RISQUE D'EXPLOSION! N'INSTALLEZ JAMAIS LE CONTRÔLEUR DANS UN
BOÎTIER SCELLÉ AVEC DES BATTERIES INONDÉES! NE PAS INSTALLER DANS
UNE ZONE CONFINÉE OÙ DES GAZ DE BATTERIE PEUVENT S'ACCUMULER.

8 | SAMLEX AMERICA INC. SAMLEX AMERICA INC. | 9
3.3.1 Step 1: Choose Mounting Location
Locate the controller in area protected from direct sun, high temperature, and water.
Make sure there is good ventilation.
3.3.2 Step 2: Check For Clearance
Place the controller in the location where it will be mounted. Verify that there is suf-
cient room to run wires and that there is sufcient room above and below the controller
for airow.
3.3.3 Step 3: Mark Holes
Use a pencil or pen to mark the 2 mounting hole locations on the mounting surface,
(Refer to the dimensional drawing in Fig 3.1)
3.3.4 Step 4: Drill Holes
Remove the controller and drill 2 holes in the marked locations. Use drill size #29 for #8
self tapping screws.
3.3.5 Step 5: Secure Controller
Place the controller on the surface and align the mounting holes with the drilled holes
in Step 3.3.4. Secure the controller in place using 2, #8 self tapping screws.
3.4 CONNECTIONS
+
12V/24V
Battery
12V/24VDC
Load (<10A)
e.g. Light
Light Switch “S1”
rated for 10A
Ground the Negative Terminal
of the battery as follows, if required by code:
• Ground to Earth Ground in shore installations
• Ground to Chassis Ground in Negative Grounded
mobile installations
12V/24V
Inverter Optional
Temp
Sensor
MSK-TS
120 VAC
Fuse F2 Fuse
F1
(15A)
Solar Panel
or Array
MSK-10A
+ –
NOTE: Maximum current on the Load
Terminals should be limited to 10A
Fig 3.2: Wiring Diagram
SECTION 3 | Installation

10 | SAMLEX AMERICA INC.
SECTION 3 | Installation
3.4.1 Step1: Battery Connection
WARNING!
RISK OF EXPLOSION OR FIRE! NEVER SHORT CIRCUIT BATTERY POSITIVE (+)
AND NEGATIVE (-).
MISE EN GARDE!
RISQUE D'EXPLOSION OU D'INCENDIE! NE COURT-CIRCUITEZ JAMAIS LA
BATTERIE POSITIF (+) ET NÉGATIF (-).
Refer to Fig 3.2
Before the battery is connected, make sure that battery voltage is greater than 8V so
as to start up the controller. If the battery system voltage is 24V, make sure the battery
voltage is not less than 18V to ensure that battery system voltage is correctly sensed as
24V (auto sensing feature for battery system voltage will erroneously sense voltage <
18V as 12V battery system). Battery system voltage will be sensed automatically when
the controller starts up for the rst time. 15A fuse "F1" is used to protect the cable run
from the battery to the charge controller against short circuit. Install the fuse not more
than 7" from the battery Positive terminal. Do not insert the fuse at this time.
3.4.2 Step 2: Load Connection through Load Terminals (Limited to 10A)
Refer to Fig 3.2
The Load Terminals of the controller can be connected to such electrical devices as lights
and other devices with load current of up to 10A. Controller provides power to the
load(s) through the battery.
When load(s) are fed from the Load Terminals, the controller will provide the following
protections on the load side:
Protect the battery as follows:
- Battery Low Voltage Alarm (≤12V/24V): Battery Status LED (2, Fig 2.1) will be steady OR-
ANGE. Output will still be available at Load Terminals. This condition will be auto reset at
12.2 / 24.4V
WARNING!
CURRENT OUTPUT ON THE LOAD TERMINALS IS LIMITED TO A MAXIMUM
OF 10A. IF HEAVIER LOADS DRAWING MORE THAN 10A LIKE INVERTER ETC.
ARE REQUIRED TO BE POWERED, CONNECT THEM DIRECTLY TO THE BATTERY
THROUGH APPROPRIATE FUSE "F2" THAT SHOULD MATCH THE DC INPUT CUR-
RENT OF THE INVERTER. THIS FUSE SHOULD ALSO BE INSTALLED WITHIN 7" OF
THE BATTERY (+) TERMINAL.

10 | SAMLEX AMERICA INC. SAMLEX AMERICA INC. | 11
MISE EN GARDE!
LA SORTIE DE COURANT SUR LES BORNES DE CHARGE EST LIMITÉE À UN
MAXIMUM DE 10A. SI DES CHARGES PLUS LOURDES DE PLUS DE 10 A
COMME L'ONDULEUR, ETC. DOIVENT ÊTRE ALIMENTÉES, CONNECTEZ-LES
DIRECTEMENT À LA BATTERIE VIA LE FUSIBLE APPROPRIÉ "F2" QUI DOIT
CORRESPONDRE AU COURANT D'ENTRÉE CC DE L'ONDULEUR. CE FUSIBLE
DOIT ÉGALEMENT ÊTRE INSTALLÉ À MOINS DE 7 "DE LA BORNE (+) DE LA
BATTERIE.
- Battery Over Voltage (≥16V/32V):
• Battery Status LED (2, Fig 2.1) will be blinking GREEN (4 Hz)
• Load will be disconnected. This condition will be automatically reset at 15.0 / 30.0V.
- Battery is Over Discharged (≤11.1V/22.2V): Battery Status LED (2, Fig 2.1) will be steady
RED. Output to Load Terminals will be disconnected. This condition will be auto reset at
12.6/ 25.2V
Protect the load as follows:
- Overload or short circuit in the load connected to the Load Terminals: Output
to Load Terminals will be disconnected (Refer to Sections 5.1.4 & 5.1.5 for details)
Connect the Positive (+) and Negative (-) of load(s) to controller Load Terminals as
shown in Fig 3.2.
An in-line Switch "S1" may be wired in series in the load Positive (+) wire as show in
Fig 3.2. This switch may be placed near the load to turn on and turn off the load locally.
If the Load Terminals of the controller are fed to a distribution panel for further distri-
bution to the loads, each load circuit may be fused separately. Ensure that the maximum
total running / start up current draw of the load(s) is less than 10A.
3.4.3 Step 3: Solar Panel / Array Connection
WARNING!
RISK OF ELECTRIC SHOCK! EXERCISE CAUTION WHEN HANDLING SOLAR
CONNECTIONS. HIGH VOLTAGE OUTPUT FROM THE PV PANEL(S)/ARRAY MAY
CAUSE SHOCK OR INJURY. COVER THE PV PANEL(S)/ARRAY FROM THE SUN
BEFORE INSTALLING SOLAR WIRING.
SECTION 3 | Installation

12 | SAMLEX AMERICA INC.
MISE EN GARDE!
RISQUE DE CHOC ELECTRIQUE! FAITES PREUVE DE PRUDENCE LORS DE LA
MANIPULATION DE L'ÉNERGIE SOLAIRE CONNEXIONS. LA SORTIE HAUTE
TENSION DES PANNEAUX PHOTOVOLTAÏQUES PEUT PROVOQUER DES
CHOCS OU DES BLESSURES. COUVREZ LES PANNEAUX PHOTOVOLTAÏQUES
DU SOLEIL AVANT D'INSTALLER LE CÂBLAGE SOLAIRE.
The controller can accept 12V (36 cell) or 24V nominal (72 cell) PV panel(s) with maxi-
mum Open Circuit Voltage of up to 50V. Continuous voltage > 50V will damage the
input section of the controller due to short circuiting of the Transient Voltage Suppres-
sor (TVS) connected across the PV input terminals.
3.4.4 Step 4: Battery Temperature Sensing & Compensation
The controller has internal battery temperature sensing that will provide approximate
battery temperature sensing in cases where the controller is located very close to the
battery.
Optional Battery Temperature Sensor Model MSK-TS (with 3m/10ft cable) may be or-
dered if the battery is installed up to 3m/10ft away from the controller. Insert the female
connector into the Jack marked "Temp Sensor" (8, Fig 2.1). Attach the cylindrical sensor
half way down the vertical side of the warmest battery in the battery bank so that the
sensor picks up the temperature of the electrolyte. Use 1 mil PVC Pipe Wrap to tape the
sensor to the battery (pre-clean the battery surface with rubbing alcohol prior to placing
the tape).
Battery Temperature Coefcient is -18mV/°C for 12V battery & -36mV/°C for 24V battery.
3.4.5 Step 5: Install Fuse
Install 15A fuse "F1" in the battery circuit.
3.4.6 Step 6: Conrm Power ON
When battery power is applied, the controller will start operating. Refer to Table 4.1
under Section 4.7 for operational information through the PV / Battery / Status LEDs (1,
2 & 3 in Fig 2.1).
SECTION 3 | Installation

12 | SAMLEX AMERICA INC. SAMLEX AMERICA INC. | 13
SECTION 4 | Operation
4.1 PRINCIPLE OF OPERATION OF SOLAR CHARGING WITH SERIES
TYPE PULSE WIDTH MODULATION (PWM) CONTROL
The design and operation of MSK-10A is based on Series Type PWM (Pulse Width
Modulation) control at PWM frequency of 25 Hz.
4.2 PWM EXPLANATION
The output of the PV Panel(s)/Array is connected to the battery in series with a Mosfet
Switch inside the controller. A Micro-controller controls the ON / OFF operation of the
Mosfet Switch to control the charging current and consequently, the State of Charge of
the battery.
A PV Panel /Array is a current source that outputs constant current equal to its Short
Circuit Current (Isc) over a wide voltage range (provided Irradiance Level, Spectrum and
Cell Temperature remain constant). For example, at STC, a typical 12V nominal, 45W PV
Panel may provide constant Short Circuit Current (Isc) of around 3A over voltage range
from 0V to around 15V.
PWM consists of repetitive cycles of controlled duration of ON and OFF states of the
Series Connected Mosfet Switch inside the controller. The sum of ON and OFF times of
one cycle is called the Pulse Period. In PWM control, the duration of the Pulse Width
(ON time) is varied (modulated) and is dened by “Duty Cycle” which is the ratio of
the “ON Time” to the “Pulse Period ”. Duty Cycle is normally specied in %. Thus, 0%
Duty Cycle will mean that the switch is constantly OFF (will output 0A) and 100% Duty
Cycle will mean that the switch is constantly ON and will output the full instantaneous
Short Circuit Current “Isc” of the panel. For Duty Cycles > 0% and < 100%, the switch
will alternate between ON and OFF states in a controlled manner in every cycle and will
output variable average current within a range of 0A to the full Short Circuit Current Isc.
Thus, through PWM control, the Mosfet Switch inside the controller converts constant
Short Circuit Current (Isc) of the PV Panel(s) to controlled average charging current at
its output by varying the Duty Cycle. The average value of the charging current is equal
to the instantaneous input value of Short Circuit Current (Isc) of the panel multiplied by
the Duty Cycle.
4.3 PWM CHARGING IN MSK-10A
Battery charging is a current based process. Current fed to the battery results in re-
charging of the cells and consequent rise in battery voltage. Controlling the current will
control battery voltage. For 100% return of capacity, and for prevention of excessive
gassing and sulfation, the battery charging voltage is required to be controlled at the
specied Voltage Regulation Set Points for Absorption, Float and Equalization Charging
Stages for different battery types. Battery can, thus, be charged at the specied Voltage
Regulation Set Points by PWM of the charging current through control of Duty Cycle as
explained above. The controller checks the battery voltage and updates the Duty Cycle
regularly at a very fast rate. The Duty Cycle is proportional to the difference between
the sensed battery voltage and the Voltage Regulation Set Point. Once the specied
Voltage Regulation Set Point is reached, it is kept steady - rise in voltage is compensated

14 | SAMLEX AMERICA INC.
SECTION 4 | Operation
by reducing the average current by reducing the Duty Cycle and fall in voltage is com-
pensated by raising the average current by raising the Duty Cycle. These fast updates on
battery voltage measurements and Duty Cycle corrections ensure charging of the bat-
tery at the specied Voltage Regulation Set Point with minimum voltage deviation.
4.3.1 Optimum PWM Frequency
The PWM frequency can range from tens of Hz to around 1000 Hz. At higher frequen-
cies, the time period between the cycles is lesser and is not sufcient to complete the
electro-chemical reactions. At lower frequencies, the rise times of the charging pulses
are lower which results in higher gas bubble formation resulting in lowering of active
surface area and increase of internal impedance. In
MSK-10A, frequency of 25 Hz is used for optimum charging performance.
4.3.2 Benets of pulsing nature of charging current during PWM
During PWM voltage regulated stages of Absorption, Float and Equalization, Duty Cycle
is lower and the charging current is in the form of pulses. Pulsing charging current al-
lows some Oxygen and Hydrogen generated during charging chemical reactions to be
chemically combined again and then absorbed. This eliminates concentration polariza-
tion and ohm polarization and reduces the internal pressure of the battery. Consequent-
ly, charging process is smoother and more capacity is returned to the battery. Further,
pulsing current provides more time to react, which reduces the gassing volume and
improves the absorption rate of charging current.
4.4 CHARGING PROFILES
The controller has been set for the following 2 Charging Proles:
(a) 3-Stage Normal Prole: See Fig 4.1A & Section 4.4.1 for details
(b) 3-Stage Equalization Prole: See Fig 4.1B & Section 4.4.2 for details
DAY
TIME
Vf
Va
Fig 4.1A 3-Stage Normal Prole
Bulk Absorption Float
Fig 4.1B 3-Stage Equalization Prole
Bulk Equalization Float
TIME
DAY
Vf
Ve
BATTERY VOLTAGE
10
11
12
13
14
15
16
20
22
24
26
28
30
32
12V
24V
STAGE 1
BULK
STAGE 2
ABSORPTION
STAGE 3
FLOAT
NIGHT NIGHT NIGHT NIGHT
STAGE 1
BULK
STAGE 2
EQUALIZATION
STAGE 3
FLOAT
2 Hrs
2 Hrs
LEGEND FOR FIG 4.1A & FIG 4.1B:
Va - Absorption Stage PWM Voltage Regulation Set Point
Ve - Equalization Stage PWM Voltage Regulation Set Point
Vf - Float Stage PWM Regulation Voltage Set Point
Figs 4.1A & 4.1B Charging Proles

14 | SAMLEX AMERICA INC. SAMLEX AMERICA INC. | 15
SECTION 4 | Operation
4.4.1 Normal Charging Prole
Please refer to Fig 4.1A
This charging cycle is carried out for normal day to day charging. Charging is sequential:
Stage 1: Bulk Stage (Maximum available Current = Instantaneous Short Circuit Current “Isc”
of the panel (Current) Stage 2: Absorption Stage (Constant Voltage) Stage 3:
Float Stage (Constant Voltage).
4.4.1.1 Stage 1 - Bulk Stage
Please refer to Fig 4.1A
This is almost a constant current stage. During this stage, the Mosfet Switch is kept at
100% Duty Cycle (ON continuously) and hence, maximum current equal to the available
instantaneous Short Circuit Current "Isc" of the panel is fed to the battery and the bat-
tery voltage starts rising. When the voltage rises to the Absorption Transition Voltage
Set Point “Va”, the controller transitions to Absorption Stage. At the end of the Bulk
Stage, the battery is charged to around 80% capacity. The balance of 20% capacity is
restored in the next Absorption Stage.
4.4.1.2 Stage 2 - Absorption Stage
Please refer to Fig 4.1A
The controller enters this stage from the previous Bulk Stage when the battery voltage
rises to the Absorption Transition Voltage Set Point “Va” which is internally set as follows:
- “Va” for 12V battery: 14.4V for Sealed Lead Acid (AGM - Absorbed Glass Mat)
- “Va” for 24 V battery: 28.8V for Sealed Lead Acid (AGM - Absorbed Glass Mat)
This stage is timed for 2 Hrs - either continuous or cumulative.
This is a constant voltage stage and the Mosfet Switch operates under PWM control
by feeding pulsing Short Circuit Current “Isc” with constantly reducing Duty Cycle (<
100% to > 0%) / average current to keep the battery voltage constant at the Absorp-
tion Transition Voltage Set Point “Va”. This is an intentional, controlled over voltage
condition for the battery for 2 Hrs. This is necessary to return the balance 20% of the
capacity. At this voltage, the battery starts gassing (evolution of Hydrogen and Oxygen
due to electrolysis of water in the electrolyte) and hence, it is necessary to exit this stage
as soon as 100% capacity is restored. If this over voltage condition is allowed to continue
after 100% recharging, the battery will be damaged due to effects of overcharging like
overheating, loss of water (ooded batteries), corrosion of the Positive plates and exces-
sive build up of pressure resulting in acid spillage due to opening of pressure activated
relief valves (sealed batteries). The balance of 20% of the battery capacity is restored in
this stage. As the battery capacity rises from 80% to 100%, the PWM control tapers the
current by continuously reducing the Duty Cycle from < 100% to > 0%.
Change over to the next Float Transition Voltage Set Point “Vf” (13.8V for 12 V bat-
tery and 27.6V for 24V battery) is possible only after the battery voltage is held at the
selected Absorption Transition Voltage Set Point “Va” for continuous or cumulative
period of 2 Hours. If Absorption Transition Voltage Set Point “Va” cannot be maintained
continuously / cumulatively for 2 Hr, transition to Float Stage WILL NOT take place.

16 | SAMLEX AMERICA INC.
SECTION 4 | Operation
4.4.1.3 Stage 3 - Float stage
Please refer to Fig 4.1A
The controller enters this stage from the previous Absorption Stage after the battery
voltage is held at the selected Absorption Transition Voltage Set Point “Va” for continu-
ous or cumulative period of 2 Hours.
This is also a constant voltage stage and the Mosfet Switch operates under PWM control
by feeding pulsing, instantaneous Short Circuit Current “Isc” with very low Duty Cycle
of > 0% to < 10% to keep the battery voltage constant at the Float Transition Voltage
Set Point “Vf” (13.8V for 12V battery and 27.6V for 24V battery). During this stage, the
battery is 100% charged and a very low “Trickle Charge” of around 0.1% of the Ah Ca-
pacity is required to be fed to the battery to compensate for self-discharge. The battery
can be left at this stage for prolonged period of time.
NOTE: During Float Stage, if the load current is more than the current from the PV
Panel(s), the battery voltage will drop. If the battery voltage drops to 13.2V for 12V
battery and 26.4V for 24V battery, the controller reverts to Stage 2: Absorption Stage.
4.5 EQUALIZATION OF LEAD ACID BATTERIES - GENERAL INFORMATION
WARNING!
RISK OF EXPLOSION AND EQUIPMENT DAMAGE!
•Equalizing ooded battery can produce explosive gases. Ensure proper ventilation
of the battery box
•Equalization may increase battery voltage to the level that can damage sensitive DC
loads. Ensure that DC input voltage of all DC loads is greater than the Equalizing
Charging Set Point. DC loads not matching Equalization Voltage Set Point, Ve (Fig 4.1B)
should be disconnected.
!CAUTION!
•Top up the electrolyte with distilled water after completion of equalization.
•Excessive overcharging and gassing too vigorously can damage the battery plates
and cause shedding of active material from the plates. An equalization that is too
high or for too long can be damaging. Review the requirements for the particular
battery being used in your system.

16 | SAMLEX AMERICA INC. SAMLEX AMERICA INC. | 17
MISE EN GARDE!
RISQUE D'EXPLOSION ET DE DOMMAGES MATÉRIELS!
• L'égalisation de la batterie inondée peut produire des gaz explosifs. Assurer une
bonne ventilation du boîtier de batterie
• L'égalisation peut augmenter la tension de la batterie au niveau qui peut
endommager les charges CC sensibles. Assurez-vous que la tension d'entrée CC de
toutes les charges CC est supérieure au point de consigne de charge d'égalisation.
Les charges CC ne correspondant pas au point de consigne de tension d'égalisation
doivent être déconnectées.
!ATTENTION!
• Remplissez l'électrolyte avec de l'eau distillée une fois l'égalisation terminée.
• Une surcharge excessive et un gazage trop vigoureux peuvent endommager les
plaques de la batterie et provoquer une perte de matière active des plaques. Une
égalisation trop élevée ou trop longue peut être dommageable. Passez en revue les
exigences de la batterie particulière utilisée dans votre système.
Equalization is intentional overcharging of the battery for controlled period of time.
Routine equalization cycles are often vital to the performance and life of a battery –
particularly in a solar system where peak sun hours per day are limited and variable and
may not be sufcient to keep the battery in a fully charged condition. Periodic equali-
zation is carried out for proper health and long life of a Lead Acid battery to prevent /
reduce the following undesirable effects:
4.5.1 Sulfation
If the charging process is not complete due to inability of the charger to provide the
required voltage levels or if the battery is left uncharged for a long duration of time,
soft Lead Sulfate crystals on the Positive and Negative plates that are formed during
discharging / self discharge are not fully converted back to Lead Dioxide on the Positive
plate and Sponge Lead on the Negative plate and get hardened and are difcult to dis-
lodge through normal charging. These crystals are non-conducting and hence, introduce
increased internal resistance in the battery. This increased internal resistance introduces
internal voltage drop during charging and discharging. Voltage drop during charging re-
sults in overheating and undercharging and formation of more Lead Sulfate crystals. Volt-
ages drop on discharging results in overheating and excessive voltage drop in the terminal
voltage of the battery. Overall, this results in poor performance of the battery. Sulfation
may be reduced partially by the stirring / mixing action of the electrolyte due to gassing
and bubbling because of intentional overcharging during the Equalization Stage.
SECTION 4 | Operation

18 | SAMLEX AMERICA INC.
SECTION 4 | Operation
4.5.2 Electrolyte Stratication
Electrolyte stratication can occur in all types of ooded batteries. As the battery is
discharged and charged, concentration of Sulphuric Acid becomes higher at the bottom
of the cell and lower at the top of the cell. The low acid concentration reduces capacity
at the top of the plates, and the high acid concentration accelerates corrosion at the
bottom of the plates and shortens battery life. Stratication can be minimized by the
Equalization Stage by raising the charging voltage so that the increased gassing and
bubbling agitates / stirs the electrolyte and ensures that the electrolyte has uniform
concentration from top to bottom. The stirring action also helps to break up any Lead
Sulfate crystals, which may remain after normal charging.
4.5.3 Unequal Charging of Cells
During normal charging, temperature and chemical imbalances prevent some cells from
reaching full charge. As a battery is discharged, the cells with lower voltage will be
drained further than the cells at the higher voltage. When recharged, the cells with the
higher voltage will be fully charged before the cells with the lower voltage. The more
a battery is cycled, the more cell voltage separation takes place. In a healthy battery, all
the individual cells will have the same voltage and same specic gravity. If there is a sub-
stantial difference in the cell voltages (0.2 V or more) and in the specic gravities (0.015
or more) of the individual cells, the cells will require equalization. Equalizing batteries
helps to bring all the cells of a battery to the same voltage. During the Equalization
Stage, fully charged cells will dissipate the charging energy by gassing while incomplete-
ly charged cells continue to charge.
4.6 EQUALIZATION CHARGING PROFILE
Please refer to Fig 4.1B
Equalization charging prole is carried out automatically every 28 days whenever the
battery is over discharged and the battery voltage drops to 11.1V for 12V battery and
22.2V for 24V battery.
4.6.1 Stage 1 Bulk Stage
Please refer to Fig 4.1B
This is the same as the Bulk Stage in the Normal Charging Cycle (See Section 4.4.1.1)
4.6.2 Stage 2 Equalization Stage
Please refer to Fig 4.1B
The controller enters this stage from the previous Bulk Stage when the battery
voltage rises to the Equalization Transition Voltage Set Point “Ve” which is internally
set as follows:
- “Ve” for 12V battery: 14.6V for Sealed Lead Acid (AGM - Absorbed Glass Mat)
- “Ve” for 24V battery: 29.2V for Sealed Lead Acid (AGM - Absorbed Glass Mat)
This stage is timed for 2 Hrs - either continuous or cumulative

18 | SAMLEX AMERICA INC. SAMLEX AMERICA INC. | 19
This is a constant voltage stage and the Mosfet Switch operates under PWM control by
feeding pulsing Short Circuit Current “Isc” with constantly reducing Duty Cycle (< 100%
to > 0%) / average current to keep the battery voltage constant at the Equalization
Transition Voltage Set Point “Ve”. This is an intentional, controlled over voltage condi-
tion for the battery for 2 Hrs. This is necessary for equalization requirements.
Change over to the next Float Transition Voltage Set Point “Vf” (13.8V for 12V
battery and 27.6V for 24V battery) is possible only after the battery voltage is held at
the selected Equalization Transition Voltage Set Point “Ve” for continuous or cumula-
tive period of 2 Hours. If Equalization Transition Voltage Set Point “Ve” cannot
be maintained continuously / cumulatively for 2 Hr, transition to Float Stage WILL NOT
take place.
4.6.3 Stage 3 - Float stage
Please refer to Fig 4.1B
The controller enters this stage from the previous Equalization Stage after the battery
voltage is held at the selected Equalization Transition Voltage Set Point “Ve” for con-
tinuous or cumulative period of 2 Hours.
This stage is the same as the Float Stage in the Normal Charging Cycle (See Section 4.4.1.3).
NOTE: During Float Stage, if the load current is more than the current from the PV
Panel(s), the battery voltage will drop. If the battery voltage drops to 13.2V for 12V
battery and 26.4V for 24V battery, the controller reverts to Stage 2: Absorption
SECTION 4 | Operation

20 | SAMLEX AMERICA INC.
SECTION 4 | Operation
4.7 LED INDICATIONS
LED indications for operational status are shown at Table 4.1.
TABLE 4.1 LED INDICATIONS FOR OPERATIONAL STATUS
Item No.
(Fig 2.1)
Description Color
of LED
LED Lighting
Pattern
Operational Status
1
PV Status LED
Green On Steady
Low solar irradiance due to poor sunlight.
PV panel/array voltage is more than 8V but
less than the battery voltage and hence,
there will be no charging.
Green Slow Blinking (1Hz) PV Voltage is > battery voltage.
Charging is taking place.
Green Fast Flashing (4Hz) PV Reverse Polarity
Green OFF PV Voltage is <5V (Night time or PV is
disconnected)
2
Battery Status LED
Green On Steady Normal Battery Voltage is >12.4V / 24.8V
Green Slow Blinking (1Hz) Battery is fully charged
Green Fast Blinking (4Hz) Battery over voltage: 16V / 32V
• Auto reset at 15.0V / 30.0V
Orange On Steady Battery under voltage warning: 12V / 24V
• Auto reset at 12.2V / 24.4V
Red On Steady Battery is over discharged to 11.1 / 22.2V.
• Auto reset at 12.6V / 25.2V
Red Slow Blinking (1Hz)
Battery over heated to >65°C. Charging is
stopped. (Optional Battery Temperature
Sensor MSK-TS has been connected)
• Auto reset at <55°C
3
Load Status LED
Red On Steady Battery power to Load Terminals is ON
Red Off Battery power to Load Terminals is OFF
Red Slow Flashing (1Hz) Overload on the Load Terminals. Battery
power to Load Terminals is OFF
Red Fast Flashing (4Hz) Short circuit at Load Terminals. Battery
power to Load Terminals is OFF
1,2,3
All 3 LED Indicators are blinking:
• PV Status LED (1) = Blinks Green
• Battery Status LED (2) = Blinks Orange
• Load Status LED (3) = Blinks Red
- Internal hot spot is >85°C
• Input and output are disconnected
- Auto reset at < 75°C
1,2,3
All 3 LED Indicators are blinking:
• PV Status LED (1) = Blinks Green
• Battery Status LED (2) = Blinks Red
• Load Status LED (3) = Blinks Red
System voltage error. Battery voltage does
not match the controller voltage. Check
battery voltage is 12V/24V. Press Load On/
Off Button (4, Fig 2.1) to clear the
malfunction.