VEVOR ML Series User manual

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Technical Support and E-Warranty Certificate www.vevor.com/support
ML MAXIMUM POWER POINT TRACKING
(MPPT) SERIES
ML2420
SOLAR CHARGE AND DISCHARGE CONTROLLER
USER MANUAL
We continue to be committed to provide you tools with competitive price.
"Save Half", "Half Price" or any other similar expressions used by us only represents an
estimate of savings you might benefit from buying certain tools with us compared to the major
top brands and doses not necessarily mean to cover all categories of tools offered by us. You
are kindly reminded to verify carefully when you are placing an order with us if you are
actually saving half in comparison with the top major brands.

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MODEL:ML2420
Have product questions? Need technical support? Please feel free to
contact us:
Technical Support and E-Warranty Certificate
www.vevor.com/support
NEED HELP? CONTACT US!
This is the original instruction, please read all manual instructions
carefully before operating. VEVOR reserves a clear interpretation of our
user manual. The appearance of the product shall be subject to the
product you received. Please forgive us that we won't inform you again if
there are any technology or software updates on our product.
ML MAXIMUM POWER
POINT TRACKING (MPPT)
SERIES

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Warning-To reduce the risk of injury, user must read
instructions manual carefully.
This device complies with Part 15 of the FCC Rules. Operation is
subject to the following two conditions:(1)This device may not cause
harmful interference, and (2)this device must accept any interference
received, including interference that may cause undesired operation.
This product is subject to the provision of European Directive
2012/19/EC. The symbol showing a wheelie bin crossed
through indicates that the product requires separate refuse
collection in the European Union. This applies to the product
and all accessories marked with this symbol. Products marked
as such may not be discarded with normal domestic waste, but
must be taken to a collection point for recycling electrical and
electronic devices
Model
ML2420
Battery voltage
12V/24V
Max. PV open circuit voltage
100V(25℃)，90V( -25℃)
Charge current
20A
Max. PV input power
20A

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Dear users, Thank you very much for choosing our products!
SAFETY INSTRUCTIONS
1. As this controller deals with voltages that exceed the top limit for
human safety, do not operate it before reading this manual carefully and
completing safety operation training.
2. The controller has no internal components that need maintenance or
service, thus do not attempt to disassemble or repair the controller.
3. Install the controller indoors, and avoid component exposure and
water intrusion.
4. During operation, the radiator may reach a very high temperature,
therefore install the controller at a place with good ventilation conditions.
5. It's recommended that a fuse or breaker be installed outside the
controller.
6. Before installing and wiring the controller, make sure to disconnect the
photovoltaic array and the fuse or breaker close to the battery terminals.
7. After installation, check if all connections are solid and reliable so as to
avoid loose connections that may give rise to dangers caused by heat
accumulation.
Warning: means the operation in question is dangerous, and you
should get properly prepared before proceeding.
!
Note: means the operation in question may cause damage.
Tips: means advice or instruction for the operator.

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Table of Contents
1. Product Introduction ............................................................................05
2. Product Installation ..............................................................................14
3. Product Operation and Display.............................................................20
4. Product Protection and System Maintenance......................................26
5. Product Specification Parameters........................................................31
6. Conversion Efficiency Curve................................................................33
7. Product Dimensions.............................................................................34

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1. PRODUCT INTRODUCTION
1 .1 Pr o du c t Ov e r v ie w
This product can keep monitoring the solar panel's generating power
and tracking the highest voltage and current values(VI)in real time,
enabling the system to charge the battery at maximum power. It's
designed to be used in off-grid solar photovoltaic systems to
coordinate operation of the solar panel, battery and load, functioning
as the core control unit in off-grid photovoltaic systems.
This product features an LCD screen that can dynamically display the
operating status, operating parameters, controller logs, control
parameters, etc. Users can conveniently check parameters by the
keys, and modify control parameters to cater to different system
requirements.
The controller utilizes standard Modbus communication protocol,
making it easy for users to check and modify system parameters on
their own.Besides, by providing free monitoring software, we give
users the maximum convenience to satisfy their varied needs for
remote monitoring.
With comprehensive electronic fault self-detecting functions and
powerful electronic protection functions built inside the controller,
component damage caused by installation errors or system failures
can be avoided to the greatest extent possible.
1 .2 P r o du c t Fe a t ur e s
With the advanced dual-peak or multi-peak tracking technology, when
the solar panel is shadowed or part of the panel fails resulting in
multiple peaks on the I-V curve, the controller is still able to accurately
track the maximum power point.
A built-in maximum power point tracking algorithm can
significantly improve the energy utilization efficiency of photovoltaic
systems, and raise the charging efficiency by 15% to 20% compared
with the conventional PWM method.

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A combination of multiple tracking algorithms enables accurate
tracking of the optimum working point on the I-V curve in an extremely
short time.
The product boasts an optimum MPPT tracking efficiency of up to
99.9%.
Advanced digital power supply technologies raise the circuit's energy
conversion efficiency to as high as 98%.
Charging program options are available for different types of batteries
including gel batteries, sealed batteries, open batteries, lithium
batteries, etc.
The controller features a limited current charging mode. When the
solar panel power exceeds a certain level and the charging current is
larger than the rated current, the controller will automatically lower the
charging power and bring the charging current to the rated level.
Instantaneous large current startup of capacitive loads is supported.
Automatic recognition of battery voltage is supported.
LED fault indicators and an LCD screen which can display
abnormality information help users to quickly identify system faults.
Historical data storage function is available, and data can be stored for
up to a year.
The controller is equipped with an LCD screen with which users can
not only check device operating data and statuses, but also modify
controller parameters.
The controller supports standard Modbus protocol, fulfilling the
communication needs of various occasions.
The controller employs a built-in over-temperature protection
mechanism. When temperature surpasses the set value, the charging
current will decline in linear proportion to the temperature so as to curb
the temperature rise of the controller, effectively keeping the controller
from being damaged by overheating.
Featuring a temperature compensation function, the controller can
automatically adjust charging and discharging parameters in order to
extend the battery's service life.
TVS lighting protection.

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1 .3 E x t er i o r an d I n t e rf a c es
Fig. 1-1 Product appearance and interfaces
No.
Item
No.
Item
①
Charging indicator
⑩
Battery "+" interface
②
Battery indicator
⑪
Battery "-" interface
③
Load indicator
@
Load "+" interface
④
Abnormality indicator
⑬
Load "-" interface
⑤
LCD screen
⑭
External temperature sampling interface
⑥
Operating keys
⑮
RS232/RS485 communication interface
⑦
Installation hole
⑧
Solar panel "+" interface
⑨
Solar panel "-" interface

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1 .4 I n tr o d u ct i o n t o M a x i mu m Po w e r P o in t Tr a c k i n g Te c h n o l og y
Maximum Power Point Tracking (MPPT) is an advanced charging
technology that enables the solar panel to output more power by adjusting
the electric module's operating status. Due to the nonlinearity of solar
arrays, there exists a maximum energy output point (maximum power point)
on their curves. Unable to continuously lock onto this point to charge the
battery, conventional controllers (employing switching and PWM charging
technologies) can't get most of the power from the solar panel. But a solar
charge controller featuring MPPT technology can continuously track arrays'
maximum power point so as to get the maximum amount of power to
charge the battery.
Take a 12V system as an example. As the solar panel's peak voltage (Vpp)
is approximately 17V while the battery's voltage is around 12V, when
charging with a conventional charge controller, the solar panel's voltage
will stay at around 12V, failing to deliver the maximum power. However, the
MPPT controller can overcome the problem by adjusting the solar panel's
input voltage and current in real time, realizing a maximum input power.
Compared with conventional PWM controllers, the MPPT controller can
make the most of the solar panel's max. power and therefore provide a
larger charging current. Generally speaking, the latter can raise the energy
utilization ratio by 15% to 20% in contrast with the
former.

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Meanwhile, due to changing ambient temperature and illumination
conditions, the max. power point varies frequently, and our MPPT
controller can adjust parameter settings according to the environmental
conditions in real time, so as to always keep the system close to the max.
operating point. The whole process is entirely automatic without the need
for human intervention.

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1 .5 C ha r g i n g S t ag e I nt r o d uc t i o ns
As one of the charging stages, MPPT cannot be used alone. It is usually
required to combine boost charge, floating charge, equalizing charge and
other charging methods to complete the battery charging process. A
complete charging process includes: Quick charge, holding charge and
floating charge. Charging curve is shown below:
a) Fast charging
At the fast charging stage, as the battery voltage has not reached the set
value of full voltage (i.e. equalizing/ boost voltage) yet, the controller will
perform MPPT charging on the battery with the maximum solar
power. When the battery voltage reaches the preset value, constant
voltage charging will begin.
b) Sustaining charging
When the battery voltage reaches the set value of holding voltage, the
controller will perform constant voltage charging. This process will no
longer include MPPT charging, and the charging current will gradually
decrease with time. Holding charge comes in two stages, i.e. equalizing
charge and boost charge. The two stages are conducted without repetition,
in which equalizing charge is started once every 30 days.
Boost charging

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By default, boost charging generally lasts for 2h, but users can adjust
preset values of duration and boost voltage point according to the actual
needs. When the duration reaches the set value, the system will then
switch to floating charging.
Equalizing charging
Warning: Risk of explosion!
In equalizing charging, an open lead-acid battery can produce explosive
gas, therefore the battery chamber shall have good ventilation conditions.
!
Note: risk of equipment damage!
Equalizing charging may raise the battery voltage to a level that may cause
damage to sensitive DC loads. Check and make sure that allowable input
voltages of all the loads in the system are greater than the set value for
battery equalizing charging.
!
Note: risk of equipment damage!
Overcharge or too much gas generated may damage battery plates and
cause active material on the battery plates to scale off. Equalizing charging
to an excessively high level or for too long a period may cause damage.
Read carefully the actual requirements of the battery deployed in the
system.
Some types of batteries benefit from regular equalizing charging which can
stir the electrolyte, balance the battery voltage and finish the
electrochemical reaction. Equalizing charging raises the battery voltage to
a higher level than the standard supply voltage and gasifies the battery
electrolyte. If the controller then automatically steers the battery into
equalizing charging, the charging duration is 120 mins (default). In order to
avoid too much generated gas or battery overheating, equalizing charging
and boosting charging won’t repeat in one complete charging cycle.
Note:
1) When due to the installation environment or working loads, the system
can't continuously stabilize the battery voltage to a constant level, the
controller will initiate a timing process, and 3 hours after the battery voltage

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reaches the set value, the system will automatically switch to equalizing
charging.
2) If no calibration has been done to the controller clock, the controller will
perform equalizing charging regularly according to its internal clock.
Floating charging
When finishing the sustaining charging stage, the controller will switch to
floating charging in which the controller lowers the battery voltage by
diminishing the charging current and keeps the battery voltage at the set
value of floating charging voltage. In the floating charging process, very
light charging is carried out for the battery to maintain it full state. At this
stage, the loads can access almost all the solar power. If the loads
consume more power than the solar panel can provide, the controller will
not be able to keep the battery voltage at the floating charging stage. When
the battery voltage drops to the set value for returning to boost charging,
the system will exit floating charging and reenter into fast charging.
2. PRODUCT INSTALLATION
2 .1 I ns t a l la t i o n P r ec a u t io n s
Be very careful when installing the battery. For open lead-acid
batteries, wear a pair of goggles during installation, and in case of
contact with battery acid, flush with water immediately.
In order to prevent the battery from being short-circuited, no metal
objects shall be placed near the battery.
Acid gas may be generated during battery charging, thus make sure
the ambient environment is well ventilated.
Keep the battery away from fire sparks, as the battery may produce
flammable gas.
When installing the battery outdoors, take sufficient measures to keep
the battery from direct sunlight and rain water intrusion.

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Loose connections or corroded wire may cause excessive heat
generation which may further melt the wire's insulation layer and burn
surrounding materials, and even cause a fire, therefore make sure all
connections are tightened securely. Wires had better be fixed properly
with ties, and when needs arise to move things, avoid wire swaying so
as to keep connections from loosening.
When connecting the system, the output terminal's voltage may
exceed the top limit for human safety. If operation needs to be done,
be sure to use insulation tools and keep hands dry.
The wiring terminals on the controller can be connected with a single
battery or a pack of batteries. Following descriptions in this manual
apply to systems employing either a single battery or a pack of
batteries.
Follow the safety advice given by the battery manufacturer.
When selecting connection wires for the system, follow the criterion
that the current density is not larger than 4A/mm2.
Connect the controller's earth terminal to the ground.
2 .2 Wi r i n g Sp e ci f i c a ti o n s
Wiring and installation methods must comply with national and local
electrical specifications. The wiring specifications of the battery and loads
must be selected according to rated currents, and see the following table
for wiring specifications:
Models
Rated charging
current
Rated
discharging
current
Battery wire
diameter
(mm2)
Load wire
diameter
(mm2)
ML2420
20A
20A
5 mm2
5 mm2

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2 .3 I ns t a ll a t i o n an d W ir i n g
Warning: risk of explosion! Never install the
controller and an open battery in the same enclosed space! Nor shall the
controller be installed in an enclosed space where battery gas may
accumulate.
Warning: danger of high voltage! Photovoltaic arrays
may produce a very high open-circuit voltage. Open the breaker or fuse
before wiring, and be very careful during the wiring process.
!
Note: when installing the controller, make sure that
enough air flows through the controller's radiator, and leave at least 150
mm of space both above and below the controller so as to ensure natural
convection for heat dissipation. If the controller is installed in an enclosed
box, make sure the box delivers a reliable heat dissipation effect.

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Step 1: choose the installation site
Do not install the controller at a place that is subject to direct sunlight, high
temperature or water intrusion, and make sure the ambient environment is
well ventilated.
Step 2: first place the installation guide plate in a proper position, use
a marking pen to mark the mounting points, then drill 4 mounting
holes at the 4 marked points, and fit screws in.
Step 3: fix the controller
Aim the controller's fixing holes at the screws fit in Step 2 and mount the
controller on.
Step 4: wire
First remove the two screws on the controller, and then begin wiring
operation. In order to guarantee installation safety, we recommend the
following wiring order; however, you can choose not to follow this order and
no damage will be incurred to the controller.

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①Connecting to external temperature sampling interface
②Connecting communication cable
③Connecting power cable
Warning: risk of electric shock! We strongly recommend that fuses or
breakers be connected at the photovoltaic array side, load side and battery
side so as to avoid electric shock during wiring operation or faulty
operations, and make sure the fuses and breakers are in an open state
before wiring.
Warning: danger of high voltage! Photovoltaic arrays may produce a
very high open-circuit voltage. Open the breaker or fuse before wiring, and
be very careful during the wiring process.
Warning: risk of explosion! Once the battery's positive and negative
terminals or leads that connect to the two terminals get short-circuited, a
fire or explosion will occur. Always be careful in operation.

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First connect the battery, then the load, and finally the solar panel. When
wiring, follow the order of first "+" and then "-".
④Power on
After connecting all power wires solidly and reliably, check again whether
wiring is correct and if the positive and negative poles are reversely
connected. After confirming that no faults exist, first close the fuse or
breaker of the battery, then see whether the LED indicators light up and the
LCD screen displays information. If the LCD screen fails to display
information, open the fuse or breaker immediately and recheck if all
connections are correctly done.
If the battery functions normally, connect the solar panel. If sunlight is
intense enough, the controller's charging indicator will light up or flash and
begin to charge the battery.
After successfully connecting the battery and photovoltaic array, finally
close the fuse or breaker of the load, and then you can manually test
whether the load can be normally turned on and off. For details, refer to
information about load working modes and operations.
Warning: when the controller is in a normal charging state,
disconnecting the battery will have some negative effect on the DC loads,
and in extreme cases, the loads may get damaged.
Warning: within 10 minutes after the controller stops charging, if the
battery's poles are reversely connected, internal components of the
controller may get damaged.
Note:
1) The battery's fuse or breaker shall be installed as close to the battery side as possible, and
it's recommended that installation distance be not more than 150mm.
2) If no remote temperature sensor is connected to the controller, the battery temperature value
will stay at 25 °C.
3) If an inverter is deployed in the system, directly connect the inverter to the battery, and do not
connect it to the controller's load terminals.

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3. PRODUCT OPERATION AND DISPLAY
3 .1 L ED In d i c at o r s
PV array indicator
Indicating the controller's current charging mode.
BAT indicator
Indicating the battery's current state.
LOAD indicator
Indicating the loads' On/ Off and state.
ERROR indicator
Indicating whether the controller is functioning normally.
PV array indicator:
No.
CHARGE STATUS
Indicator state
Charging state
①
Steady on
MPPT charging
②
Slow flashing
(a cycle of 2s with on and off each
lasting for 1s)
Boost charging
③
Single flashing
(a cycle of 2s with on and off lasting
respectively for 0 1s and 1 9s)
Floating charging
④
Quick flashing
(a cycle of 0.2s with on and off each
lasting for 0.1s)
Equalizing charging
⑤
Double flashing
(a cycle of 2s with on for 0.1s, off for
0.1s, on again for 0.1s, and off again
for 1.7s)
Current-limited
charging
⑥
Off
No charging