Renogy RMS-DCDC-US User manual

Version 1.0
FOR DC-DC BATTERY CHARGER SERIES
MONITORING
SCREEN
RMS-DCDC

01
General Safety Information
This manual contains important installation and operation
instructions for the monitoring screen. Please observe these
instructions and keep them located near the monitoring screen for
further reference. The following symbols are used throughout the
manual to indicate potentially dangerous conditions or important
safety information.
Make sure all connections going into and from the DC-DC are
tight. There may be sparks when making connections,
therefore, make sure there are not flammable materials or
gases near installation.
DO NOT expose it to direct sunlight, rain, snow, moisture, or
liquids of any type.
Important Safety Instructions
Please save these instructions.
Indicates a potentially dangerous condition. Use
extreme caution when performing this task.
Indicates a critical procedure for the safe and proper
installation and operation of the monitoring screen.
Indicates a procedure or function that is important
to the safe and proper installation and operation of
the monitoring screen.
NOTE
CAUTION
WARNING
DO NOT puncture, drop, crush, burn, penetrate, or strike
the monitoring screen.
DO NOT open, dismantle, or modify the monitoring screen.
Installation Information
DO NOT attempt connecting the monitoring screen to other
DC-DC or systems.
The DC-DC are suitable for 12V Battery Banks ONLY.
Always make sure DC-DC is in OFF position and disconnect all
sources when working on any circuit associated with the DC-DC.

02
Table of Contents
Important Safety Instructions 01
General Information 04
Product Overview 05
Identification of Parts 05
Dimensions 06
Voltage Interface 18
Operation 14
Troubleshooting 31
Technical Specifications 35
LCD Icons 15
LCD Menu Overview 17
Kilowatt Interface 18
Current Interface 18
Temperature Interface 18
Working Mode 19
Parameter Setting 23
Set the Battery Type 23
Clear KWh to 0 28
Set Current Limiting 28
Change from Celsius to Fahrenheit 30
Installation 08

03
General Information
Plug and Play
Accurate Readings
The RMS-DCDC is a high precision meter designed for DC-DC
MPPT Series on board battery chargers. Featuring a backlit display
and flush-mountable, it is engineered for an aesthetically clean and
professional look inside vehicle cabins. Utilize the 4-key input to
navigate through the backlit LCD for system information, configure
charging parameters, as well as identify any error codes. The
RMS-DCDC is the perfect companion offering operator feedback
your 2-battery system and keeping up to date with important system
information.
Dual Battery Monitoring
Stay informed on the charging status of your house and auxiliary
battery and monitor overall system health.
Adjustable Parameters
Program your charger settings, volts, and amps directly through
the monitoring screen.
Precise tracking and monitoring ensure latest real-time system
information.
Simply connect an RJ45 directly to your DC-DC and let the
screen take care of the rest.
Key Features

04
Product Overview
LCD Screen
Page Up
Page Down
Previous Page
Enter
Front Cover Plate
Mounting Holes
RJ45 Communication Port
①
②
③
④
⑤
⑥
⑦
⑧
Identification of Parts
②① ③ ④ ⑤
RMS-DCDC
⑥⑦⑧

05
Dimensions
1.24in
0.8in
31.5mm
19.9mm
Dimensions have a tolerance of ±0.5mm
RMS-DCDC
110.0mm
4.3in
87.5mm
3.4in
2.8in
70.0mm
NOTE

06
Additional Components
RJ45 Communication Cable
You may use ethernet cables CAT5 or higher.
The RJ45 Communication Cable (5m/16.4ft) is used to connect the
monitoring screen to t power supply and data transmission.
Self-tapping Screws (4)
The Self-tapping Screws (M2.9x13) are used fix the monitoring
screen on the mounting surface.
NOTE

07
NOTE
Before installation, check to make sure the power is working
properly. Resolve any issues before installation of monitoring
screen and cable.
The following are recommendations for installation. There will be
multiple mounting methods depending on user’s applications.
Clearance of at least 2 inches (50 mm) behind the unit is recommend-
ed to allow for the bending radius of the RJ45 Communication Cable
that connects to the monitoring screen.
The RMS-DCDC requires a flush mount installation. The RMS-DC-
DC’s faceplate will be flush with the mounting surface and the
body of the meter.
Before the installation of the monitoring screen, it is recommended
to have the following tools available:
CAUTION
Installation
Before drilling, make sure there are no electrical component or
other obstacles that may interfere with installation on the other
side of the mounting surface.
WARNING
Preparation
Choosing an Installation Location
Pencil
Drill
Jigsaw
Phillips screwdriver

08
2. Use the monitoring screen as a template to mark the screw holes
and trace the cut-out area on the mounting surface with a pencil.
1. Remove the snap-fit Front Cover Plate from the monitoring
screen.
3. Cut out a rectangle area for the monitoring screen on the
mounting surface with a jigsaw. You may also use the cut out
dimension specified after Step 2.
5. Put the monitoring screen into the cut-out area and align the
mounting holes on the monitoring screen with the pre-drilled screw
holes.
6. Fix the monitoring screen on the mounting surface with the
included four self-tapping screws.
7. Re-attach the snap-fit Front Cover Plate to the monitoring
screen.
4. Pre-drill four screw holes on the mounting surface with a drill.
Mounting the Monitoring Screen
1

09
2
3

10
4
Cutout Dimensions (L x H x W):
87.5 x 58.0 x 19.9mm
(3.44 x 2.28 x 0.78in)
87.5mm
3.44in
58.0mm
2.28in
19.9mm
0.78in
5

11
7
6

12
Connecting to the DCDC
Utilize the included RJ45 communication cable to connect between
the DC-DC MPPT RS485 Port and the back of the RMS-DCDC.
RJ45 Communication cable

13
Key Meaning
Page Up
Page Down
Operation
Use the following keys to navigate through the monitoring screen
Previous Page
Exit Parameter Setting Mode
Enter—Tap to Enter
Parameter Setting Key—Hold for approximately
2~3 seconds to enter parameter setting mode

14
LCD Icons
Key Features
2 1 12 11 10
876543
9
1. System Voltage
The 12V system voltage will be illuminated while the RMS-DC-
DC is powered on or during operation.
2. State of charge
Whether charging with PV, Alternator, or PV + Alternator, the
charge state will reflect either MPPT, BOOST, FLOAT. Only
batteries with an equalization charge will see EQUALIZE.In
addition, Lithium batteries will display MPPT and Boost only.
3. System Error
Illuminates when there is a fault or error. It will be followed by an
error code identifying the system error. The icon must be cleared
by fixing the error code condition by troubleshooting your system.

15
4. Solar Charging Icon
Indicates solar is charging the house battery. Solar will take
priority over alternator charging.
Error Code Description
Normal
5. House Battery Icon
When “H” is shown with parameters, it refers to the house battery
parameters.
6. Parameter Units
Total Charging Amps (A), Instant Kilowatt (KWH), Voltage (V), and
Temperature (◦C or ◦F).
7. Error Codes
System error will display a relevant error code from E0~E03、
E05~E10、E12、E13. By default, E0 means no fault and will
display for 3-seconds before disappearing. The following error
codes may come up and will need some troubleshooting to clear
them. Refer to the Troubleshooting section.
E0
House Battery Over-discharged
E1
House Battery Over-voltage
E2
House Battery Low Voltage Warning
E3
House Battery Low Temperature ProtectionE5
House Battery High Temperature Protection
E7
Alternator Over-voltage Warning
E8
Alternator Overcurrent
E9
PV Input Over-voltage
E10
Starting Battery Polarity Reversed
E12
Solar Panel Polarity Reversed
E13
E6 Controller High Temperature Warning

16
LCD Menu Overview
8. House Battery SOC Icon
Indicates the estimated state of charge of the house battery. State
of charge is voltage based and will be split into 4 bars each
representing 25% increments for a total of 100%. Factors such as
temperature, charge, and discharge can affect the state of charge.
To get the most accurate SOC readings, the battery needs to rest
in the open circuit state for at least 30-45min.
9. Alternator Charging Arrow
Shows that alternator is charging the starter battery or house battery
circuits.
10. Alternator Icon
Displays when connected to a starter battery successfully. Charging
will be indicative by the charging arrow mentioned above.
11. Battery Parameters
Battery Amps (A), Historical Kilowatt-hour Generation (KWH),
Voltage (V), and Temperature (◦C or ◦F) relevant to the starter battery.
12. Starter Battery Icon
When “S” is shown with parameters, it refers to the starter battery
parameters.
Navigate through the RMS-DCDC screens by pressing the page
up or page down keys.

17
Voltage Interface
The top line displays the house
battery (DC Output) voltage as
well as a graphical display of
the battery using voltage-based
SOC. Each bar represents 25%
for a total of 100%. The bottom
line shows the starter battery
(DC Input) voltage.
Kilowatt Interface
The top line displays instantaneous
watts as a factor of kilowatts (KW).
This will be the charging voltage (V)
multiplied by the charging current (A)
to display Kilowatts. 1 KW = 1000W.
The bottom line displays historical
kilowatt hour generation information
(KWH) and will accumulate the data.
Current Interface
Temperature Interface
The top line displays overall charging
current to the house battery (Only
Solar, Only Alternator, or Solar +
Alternator). The bottom line displays
the input alternator current.
Temperature will be in Celsius (◦C)
by default. The top line shows the
house battery temperature relative
to the DC-DC MPPT. When connected
to the Temperature Sensor (Model:
RTSCC), then it will show the relevant
sensor temperature. The bottom line
displays the internal temperature
of the DC-DC MPPT

18
Once the RMS-DCDC is on, it will display different pages depending
on the sources connected. PV Charing Mode will take priority when
charging the house or starter batteries. House battery information will
appear on the top line and starter battery information in the bottom line.
Working Mode
Only PV Charging—Starter Battery & House Battery
Connected
1.PV charging requires a minimum
of 15V for 10s to start charging. PV
will prioritize charge to the house
battery bank and charge until the
lead-acid battery reaches the Float
Voltage. If the house battery is
Lithium, then it will reach the Boost
Voltage and derate amps complete-
ly to indicate fully charged since
they do not have a Float Voltage.
2.Next, PV charging will maintain
the house battery and trickle
charge the starter battery at 13.8V.
The Generator charging arrow will
appear during this time.
*Note: The maximum charging
amps for the starter battery will
be 50% of the Amp Rating.
3.After charging the starter battery
for 1 minute, it will disconnect for
30s and check the starting battery
voltage. If the starter battery drops
below 12.7V, charge will continue again
and stop when the actual starter
battery voltage is higher than 13.2V

19
4.When and if PV charges both the
house battery and starter battery at
the same time, there will be a solar
icon above the H and S.
Only ALT Charging—Starter Battery & House Battery
Connected
1.ALT charging will follow this chart, depending on your
alternator type.
Alternator Type
Cut-in Cut-off
Starting Battery Voltage
Smart Alternator
Traditional Alternator ＞13.2V,
for 15 seconds ＜12.7V
＞12.0V,
for 15 seconds ＜11.5V
2. ALT will prioritize charge to the
starter battery bank and charge until
the starter battery reaches above
the Cut-in Voltage.
3.Next, ALT will charge the house
battery until the lead-acid battery
reaches the Float Voltage. If the
house battery is Lithium, ALT will
need to reach the Boost Voltage and
derate amps completely to indicate
fully charged.