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

2
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.

3
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.

4
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

5
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.

6
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)

7
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.

8
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

9
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.
5
1
4
30A/40A MPPT
6
PV
Terminal
BATTERY
Terminal
LOAD
Terminal
20A MPPT
1
2
3
4
5
6
7
7
7

10
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.

11
Battery
Load (optional)
1
2
3
1
2

12
Solar Panels
MT-5 Tracer (optional)
2
2
1
1

13
Mounting Recommendations
WARNING: Never install the controller in a sealed enclosure with flooded batteries.
Gas can accumulate and there is a risk of explosion.
1. Choose Mounting Location—place the controller on a vertical surface protected
from direct sunlight, high temperatures, and water. Make sure there is good
ventilation.
2. Check for Clearance—verify that there is sufficient room to run wires, as well as
clearance above and below the controller for ventilation. The clearance should be
at least 6 inches (150mm).
3. Mark Holes
4. Drill Holes
5. Secure the charge controller.
Operation
After connecting the battery to the charge controller, the controller will turn on
automatically. The MPPT charge controllers are very easy to use and have a simple
display for Mode & Timer 1, Timer 2, and Battery Type Information. To cycle through the
different digital displays, simply press the big orange Set button. You will notice that a red
LED will turn on depending on whichever mode is highlighted followed by a number on
the LCD display.
NOTE: The MPPT Charge Controller works automatically and does need the
timer(s) function set in order to operate. The timers(s) are simply an added feature
for loads connected directly to the charge controller.
6 inches
(150mm)
6 inches
(150mm)

14
NOTE: In order to adjust a parameter go to your desired LED indicator, hold the
orange set button for a little over 5 seconds. Wait until the number inside the Work
Mode display flashes. You are now in parameter setting mode and can continually
press the orange set button and cycle through the numbers until the desired
number is reached. The setting will be in effect once the new number stops
flashing.
Load Work Mode Setting
NOTE: In order to adjust a parameter go to your desired LED indicator, hold the
orange set button for a little over 5 seconds. Wait until the number inside the Work
Mode display flashes. You are now in parameter setting mode and can continually
press the orange set button and cycle through the numbers until the desired
number is reached. The setting will be in effect once the new number stops
flashing.
NOTE: When not using electrical loads, set the timers to “n” (disable) as shown in
the Timing Parameters (Page 17)

15
The MPPT Charge Controller is equipped with a programmable dual timer function for the
load terminal. Depending on the user setting, the timer(s)’ purpose is to turn on/off the
load for a selected amount of time during the day, during the night, or manually to the
user’s discretion. Each numerical indicator on the work mode has a specific timer function
corresponding to it. There are four Load Control Settings: 1. Dusk to Dawn, 2. Light ON
+ Timer, 3. Test Mode, and 4. Manual Mode.
CAUTION: Be mindful of the maximum load draws for the charge controller.
Overload could result in damage to the charge controller terminal, or the charge
controller itself.
NOTE: The load terminal is commonly used for small lights or other low amp
drawing devices. The terminal is powered by the battery bank connected to the
charge controller. The load will NEVER draw power directly from the solar panels.
NOTE: With the exception of Manual Mode, none of the dual timer modes will work
unless there is a PV array connected to the charge controller.
NOTE: Threshold Voltages can be found under Technical Specifications.
1. Dusk to Dawn (T1:#0)
The load terminal will be on all night and will be off during the day. The charge controller
recognizes that it is nighttime when the solar module voltage goes below the point of
NTTV (Night Time Threshold Voltage). The load terminal will recognize this voltage drop
and undergo a 10 minute delay before turning on the load terminal.
In that same respect, the charge controller will recognizes day time when the solar module
voltage goes above point of DTTV (Day Time Threshold Voltage). The controller will
recognize the voltage increase and undergo a 10 minute delay before turning off the load
terminal.
NOTE: Only Timer 1 can be set to Dusk to Dawn Mode. As a result, Timer 2 will be
disabled when Timer 1 is set to Dusk to Dawn Mode.
2. Load ON + Timer (T1&T2:#1-15)
The charge controller recognizes that it is nighttime when the solar module voltage goes
below the point of NTTV (Night Time Threshold Voltage). The load terminal will recognize
this voltage drop and undergo a 10 minute delay before turning on the load terminal.
Timer 1 will control the amount of hours the load will remain on after the NTTV and the
10 minute delay. The user will be able to choose between numbers 1 and 15 on Timer 1.
In that same respect, the charge controller will recognizes day time when the solarmodule

16
voltage goes above point of DTTV (Day Time Threshold Voltage). The controller will
recognize the voltage increase and undergo a 10 minute delay before turning off the load
terminal. If Timer 1 has already been set to a time frame before night time is over, then
Timer 2 will be able control the amount of hours the load turns on again before reaching
the DTTV. The user will be able to choose between numbers 1 and 15 on Timer 2.
NOTE: If the charge controller goes above the DTTV then the controller will turn off
even if the Timer was set to 15 hours. The timer function works with whichever
function it experiences first.
Graphical Display of the Dual Timer Function
3. Test Mode (T1:#16)
The load terminal will be on all night and will be off during the day. Test mode does not
have the 10 minute delay between the NTTV and DTTV giving the user faster results if
they are trying to test whether the load terminal timer function is operating correctly.
NOTE: Only Timer 1 can be set to Test Mode. As a result, Timer 2 will be disabled
when Timer 1 is set to Test Mode.
4. Manual Mode (T1:#17)
Manual mode eliminates any timer functions and leaves load control to the discretion of
the user. Once manual mode is set, simply use the orange set button to click the load on
or off indefinitely.
NOTE: Only Timer 1 can be set to Manual Mode. As a result, Timer 2 will be disabled
when Timer 1 is set to Manual Mode.

17
Timing Parameters
Timer 1
Digital Display
Timer 2
Disable
N
Disable
Dusk To Dawn
0
-----
Load on 1 hour AFTER sunset
1
Load on 1 hour BEFORE sunrise
Load on 2 hour AFTER sunset
2
Load on 2 hour BEFORE sunrise
Load on 3 hour AFTER sunset
3
Load on 3 hour BEFORE sunrise
Load on 4 hour AFTER sunset
4
Load on 4 hour BEFORE sunrise
Load on 5 hour AFTER sunset
5
Load on 5 hour BEFORE sunrise
Load on 6 hour AFTER sunset
6
Load on 6 hour BEFORE sunrise
Load on 7 hour AFTER sunset
7
Load on 7 hour BEFORE sunrise
Load on 8 hour AFTER sunset
8
Load on 8 hour BEFORE sunrise
Load on 9 hour AFTER sunset
9
Load on 9 hour BEFORE sunrise
Load on 10 hour AFTER sunset
10
Load on 10 hour BEFORE sunrise
Load on 11 hour AFTER sunset
11
Load on 11 hour BEFORE sunrise
Load on 12 hour AFTER sunset
12
Load on 12 hour BEFORE sunrise
Load on 13 hour AFTER sunset
13
Load on 13 hour BEFORE sunrise
Load on 14 hour AFTER sunset
14
Load on 14 hour BEFORE sunrise
Load on 15 hour AFTER sunset
15
Load on 15 hour BEFORE sunrise
Test Mode
16
------
Manual Mode
17
------
Battery Type Setting
NOTE: In order to adjust a parameter go to your desired LED indicator, hold the
orange set button for a little over 5 seconds. Wait until the number inside the Work
Mode display flashes. You are now in parameter setting mode and can continually
press the orange set button and cycle through the numbers until the desired
number is reached. The setting will be in effect once the new number stops
flashing.
Battery Type
Digital Display
Sealed Lead Acid
1
Gel
2
Flooded
3

18
LED Indications
Charge Indicator
Solid. Battery is charging
No light. Not charging.
Flashing. Battery is over-voltage.
Battery Indicator
Solid. Battery Normal.
Flashing. Battery is Full.
Solid. Battery is under-voltage.
Solid. Battery is over-discharged.
Flashing. The load is either over-current or short-
circuited.
Work Mode
The PV’s open circuit voltage (Voc) is exceeding the
maximum rating of the charge controller. The array
will remain disconnected until the Voc is at a safe
rating.
The PV’s input current is exceeding the maximum
rating of the charge controller. The array will remain
as is until solution is implemented.
P
C

19
System Status Troubleshooting
Charge Indicator
Troubleshoot
Off during
daylight
Ensure that the PV wires are correctly and tightly secured inside
the charge controller PV terminals. Use a multi-meter to make sure
the poles are correctly connected to the charge controller.
Flashing Green
Use a multi-meter to check the battery voltage and make sure it is
within specification for the charge controller. NEVER disconnect
battery without disconnecting the solar panels first.
Battery Indicator
Troubleshoot
Solid orange
light
Disconnect loads, if any, and let the PVmodules charge the battery
bank. Use a multi-meter to frequently check on any change in
battery voltage to see if condition improves. This should ensure a
fast charge. Otherwise, monitor the system and check to see if
system improves.
Solid Red
The controller will have cutoff the output of the battery to ensure
that it charges. Make sure there are no excessive loads and give
the system appropriate time and sunlight to charge. Monitor
readings with a multi-meter to see if they system improves.
Flashing Red
Light
System could be overload or short-circuit.
Overload: Use a multi-meter to check load draw and limit loads if
possible. If no progress, disconnect all loads and gradually
reconnect loads to see if the condition improves.
Short-circuit: Upon experiencing its first short circuit, the
controller will cut off for 10 seconds, and then presume normal
operation. Upon the second short-circuit, the controller will not
automatically reboot and the user must press the orange button to
resume controller working.

20
Work Mode
Troubleshoot
The letter “C”
The controller is registering an overcurrent from the solar modules.
Check solar panel specifications and verify with a multi-meter to
see that they match. Next check to see if the panel specifications
(Voc and Isc) are within specification for the charge controller.
The letter “P”
The controller is registering an overcurrent from the solar panels.
No panels will remain in open circuit unless there is a reduction in
the voltage that is safe enough to pass through the controller. Make
sure to use a multi-meter to check the specifications of the panel
are correct, and that they do not exceed the ratings of the
controller.
Maintenance
WARNING: Risk of Electric Shock! Make sure that all power is turned off before
touching the terminals on the charge controller.
For best controller performance, it is recommended that these tasks be performed from
time to time.
1. Check that controller is mounted in a clean, dry, and ventilated area.
2. Check wiring going into the charge controller and make sure there is no wire
damage or wear.
3. Tighten all terminals and inspect any loose, broken, or burnt up connections.
4. Make sure readings in the LCD and LED are consistent. Take necessarycorrective
action.
5. Check to make sure none of the terminals have any corrosion, insulation damage,
high temperature, or any burnt/discoloration marks.