Renogy RNG-CTRL-MPPT20 User manual

MPPT Tracer Series
RENOGY 20A | 40A
Maximum Power Point Tracking Solar Charge Controller
2775 E. Philadelphia St., Ontario, CA 91761
1-800-330-8678
Version: 1.1

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Important Safety Instructions
Please save these instructions.
This manual contains important safety, installation, and operating instructions for the
charge controller. The following symbols are used throughout the manual to indicate
potentially dangerous conditions or important safety information.
WARNING: Indicates a potentially dangerous condition. Use extreme caution when
performing this task.
CAUTION: Indicates a critical procedure for safe and proper operation of the controller
NOTE: Indicates a procedure or function that is important to the safe and proper operation
of the controller.
General Safety Information
Read all of the instructions and cautions in the manual before beginning the
installation.
There are no serviceable parts for this controller. Do NOT disassemble or attempt
to repair the controller.
Do NOT allow water to enter the controller.
Make sure all connections going into and from the controller are tight.
Charge Controller Safety
NEVER connect the solar panel array to the controller without a battery. Battery
must be connected first.
Ensure input voltage does not exceed 100 VDC to prevent permanent damage.
Use the Open Circuit (Voc) to make sure the voltage does not exceed this value
when connecting panels together.
Do not exceed 20A (Tracer-2210RN) or 40A (Tracer-4210RN). The Short Circuit
(Isc) of the solar array should be less than 20A (Tracer-2210RN) or 40A (Tracer-
4210RN).
Battery Safety
Use only sealed lead-acid, flooded, or gel batteries which must be deep cycle.

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Explosive battery gases may be present while charging. Becertain there is enough
ventilation to release the gases.
Be careful when working with large lead acid batteries. Wear eye protection and
have fresh water available in case there is contact with the battery acid.
Carefully read battery manuals before operation.
Do NOT let the positive (+) and negative (-) terminals of the battery touch each
other.
Recycle battery when it is replaced.
Over-charging and excessive gas precipitation may damage the batteryplates and
activate material shedding on them. Too high of an equalizing charge or too long
of one may cause damage. Please carefully review the specific requirements of
the battery used in the system.
Equalization is carried out only for non-sealed / vented/ flooded / wet cell lead acid
batteries.
Do NOT equalize sealed / VRLA type AGM / Gel cell batteries UNLESS permitted
by battery manufacturer.
WARNING: Connect battery terminals to the charge controller BEFORE connecting
the solar panel(s) to the charge controller. NEVER connect solar panels to charge
controller until the battery is connected.
WARNING: Do NOT connect any inverters or battery charger into the load terminal
of the charge controller.
WARNING: Once equalization is active in the battery charging, it will remain in this
stage as long as there is adequate charging current from the solar panel. There
should be NO load on the batteries when in equalization charging stage.

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Table of Contents
General Information......................................................................................................5
Optional Components...................................................................................................8
Identification of Parts....................................................................................................9
Installation ...................................................................................................................10
Operation.....................................................................................................................13
Load Work Mode Setting.........................................................................................14
Battery Type Setting................................................................................................17
LED Indications...........................................................................................................18
System Status Troubleshooting ................................................................................19
Maintenance ................................................................................................................20
Fusing ..........................................................................................................................21
Technical Specifications ............................................................................................22
Electrical Parameters.................................................................................................22
Battery Charging Parameters ....................................................................................22
Mechanical Parameters.............................................................................................23
Environment Parameters...........................................................................................23
PV Power –Conversion Efficiency Curves—20A MPPT..........................................24
PV Power –Conversion Efficiency Curves—40A MPPT..........................................27
Dimensions..................................................................................................................30

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General Information
The RENOGY MPPT series controller is suitable for off-grid solar applications. It protects
the battery from being over-charged by the solar modules and over-discharged by the
loads. The controller features a smart tracking algorithm that maximizes the energy from
the solar PV module(s) and charge the battery. At the same time, the low voltage
disconnect function (LVD) will prevent the battery from over discharging.
The MPPT Charge Controller charging process has been optimized for long battery life
and improved system performance. The comprehensive self-diagnostics and electronic
protection functions can prevent damage from installation mistakes or system faults. In
addition, the charge controller has an RJ45 interface to allow communication with a
Tracer meter for remote monitoring.
Key Features
12V / 24V auto recognition. 
Advanced maximum power point tracking technology to optimize the use of the PV
system. 
Peak conversion efficiency of 97 %, high Tracking efficiency of 99%. 
Fast sweeping of the entire I-V curve, several seconds tracking speed. 
Widely used, automatic recognition of day and night. 
Timer function with 1-15 hour option for streetlight.
Unique dual timer function; enhance the flexibility lighting systems. 
Deep Cycle Sealed, Gel and Flooded battery option.
Adopting temperature compensation and correcting the charging and discharging
parameters automatically, improving battery lifetime. 
Electronic protection: Overcharging, over-discharging, overload, and short circuit.
Reverse protection: Any combination of solar module and battery, without causing
damage to any component. 
Excellent thermal design and natural air-cooling.
RJ45 interface for use with the remote meter MT-5, convenient to check operating
parameters of controllers. 
MPPT Technology
The MPPT Charge Controller utilizes Maximum Power Point Tracking technology to
extract maximum power from the solar module(s). The tracking algorithm is fully
automatic and does not require user adjustment. MPPT technology will track the array’s
maximum power point voltage (Vmp) as it varies with weather conditions, ensuring that the
maximum power is harvested from the array throughout the course of the day.
Current Boost
In many cases, the MPPT charge controller will “boost” up the current in the solar system.

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The current does not come out of thin air. Instead, the power generated in the solarpanels
is the same power that is transmitted into the battery bank. Power is the product of Voltage
(V) x Amperage (A). Therefore, assuming 100% efficiency:
Power In = Power Out
Volts In * Amps In = Volts out * Amps out
Although MPPT controllers are not 100% efficient, they are very close at about 92-95%
efficient. Therefore, when the user has a solar system whose Vmp is greater than the
battery bank voltage, then that potential difference is proportional to the current boost.
The voltage generated at the solar module needs to be stepped down to a rate that could
charge the battery in a stable fashion by which the amperage is boosted accordingly to
the drop. It is entirely possible to have a solar module generate 8 amps going into the
charge controller and likewise have the charge controller send 10 amps to the battery
bank. This is the essence of the MPPT charge controllers and their advantage over
traditional charge controllers. In traditional charge controllers, that stepped down voltage
amount is wasted because the controller algorithm can only dissipate it as heat. The
following demonstrates a graphical point regarding the output of MPPT technology.
Limiting Effectiveness
Temperature is a huge enemy of solar modules. As the environmental temperature
increases, the operating voltage (Vmp) is reduced and limits the power generation of the
solar module. Despite the effectiveness of MPPT technology, the charging algorithm will
possibly not have much to work with and therefore there is an inevitable decrease in
performance. In this scenario, it would be preferred to have modules with higher nominal
voltage, so that despite the drop in performance of the panel, the battery is still receiving
a current boost because of the proportional drop in module voltage.
Typical Battery
Voltage Range
Maximum
Power Point
Traditional
Controller
Operating
Range
Maximum
Power Point
Current vs. Voltage (12V System)
Output Power (12V System)

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Four Charging Stages
The MPPT charge controllers have a 4-stage battery charging algorithm for a rapid,
efficient, and safe battery charging. They include: Bulk Charge, Boost Charge, Float
Charge, and Equalization.
Bulk Charge: This algorithm is used for day to day charging. It uses 100% of available
solar power to recharge the battery and is equivalent to constant current.
Boost Charge: When the battery has charged to the Boost voltage set-point, it undergoes
an absorption stage which is equivalent to constant voltage regulation to prevent heating
and excessive gassing in the battery. The default time for this is 120 minutes in the MPPT
controllers but it can be customizable as needed.
Float Charge: After Boost Charge, the controller will reduce the battery voltage to a float
voltage set point. Once the battery is fully charged, there will be no more chemical
reactions and all the charge current would turn into heat or gas. Because of this, the
charge controller will reduce the voltage charge to smaller quantity, while lightly charging
the battery. The purpose for this is to offset the power consumption while maintaining a
full battery storage capacity. In the event that a load drawn from the battery exceeds the
charge current, the controller will no longer be able to maintain the battery to a Float set
point and the controller will end the float charge stage and refer back to bulk charging.
Equalization: Is carried out every 28 days of the month. It is intentional overcharging of
the battery for a controlled period of time. Certain types of batteries benefit from periodic
equalizing charge, which can stir the electrolyte, balance battery voltage and complete
chemical reaction. Equalizing charge increases the battery voltage, higher than the
standard complement voltage, which gasifies the battery electrolyte.

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WARNING: Once equalization is active in the battery charging, it will remain in this
stage as long as there is adequate charging current from the solar panel. There
should be NO load on the batteries when in equalization charging stage.
WARNING: Over-charging and excessive gas precipitation may damage the battery
plates and activate material shedding on them. Too high of equalizing charge or for
too long may cause damage. Please carefully review the specific requirements of
the battery used in the system.
WARNING: Equalization may increase battery voltage to a level damaging to
sensitive DC loads. Ensure that all load allowable input voltages are greater than
the equalizing charging set point voltage.
Optional Components
*The MPPT 20A/40ACC is shipped by itself, without any additional components.
Optional components that require a separate purchase:
Renogy MT-5 Tracer Meter for MPPT Charge Controller
(MT-5): A self-diagnostics meter ideal for monitoring and
displaying the current solar system status information and
any error indications the system might be experiencing. It
is perfect for circumstances where the user cannot easily
access the controller or modify its parameters. It is supplied
with a 6.5ft. Cable and a mounting frame that connects to
the RJ45 port on the MPPT.
Figure 1

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Identification of Parts
Key Parts
1. Charging LED Indicator
2. Battery Status LED indicator
3. Local Temperature Sensor—acquires ambient temperature to perform temperature
compensation for charging and discharging.
4. Setting LED Indicators—Work Mode, Timers, and Battery Selection
5. LCD Display—load and work more status is displayed
6. Set Button—Adjust parameters, cycle through settings, or turn load On/Off
7. RJ45 port for MT-5 Tracer (optional accessory)—connects remotelyto temperature
sensor in order to acquire ambient temperature.
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1
4
30A/40A MPPT
6
PV
Terminal
BATTERY
Terminal
LOAD
Terminal
20A MPPT
1
2
3
4
5
6
7
7
7

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INVERTER
BATTERY
CHARGER
HIGH AMP
DRAWING DEVICE
Installation
Recommended tools to have before installation:
Flathead Screwdriver
Multi-Meter
WARNING: Connect battery terminal wires to the charge controller FIRST then
connect the solar panel(s) to the charge controller. NEVER connect solar panel to
charge controller before the battery.
WARNING: Do NOT connect any inverters or battery chargers into the load terminal
of the charge controller
CAUTION: Do not over-torque or over tighten the screw terminals. This could
potentially break the piece that holds the wire to the charge controller.
CAUTION: Refer to the technical specifications for max wire sizes on the
controller and for the maximum amperage going through wires.
You are now ready to begin connecting your battery to your charge controller.