Digital Mobile Charge Battery to Battery Manual
Digital Mobile Charge
Advanced Electronic In-Transit 4-Stage Battery to Battery Charger
Owner’s Manual and Installation Guide
Part Number
Digital Mobile Charge
24V to 24V Battery to Battery
Advanced In-Transit 4-Stage Charger
(Input 20 Amp, Output 20 Amp)
Digital Mobile Charge
24V to 12V Battery to Battery
Advanced In-Transit 4-Stage Charger
(Input 20 Amp, Output 40 Amp)
Digital Mobile Charge
12V to 12V Battery to Battery
Advanced In-Transit 4-Stage Charger
(Input 40 Amp, Output 40 Amp)
Digital Mobile Charge
12V to 24V Battery to Battery
Advanced In-Transit 4-Stage Charger
(Input 40 Amp, Output 20 Amp)
Your Satisfaction is Important to us. Do Not Return this Product to the Retailer or
Dealer for any Service or Warranty Requirements. Please Call our Customer Care
Department line at 1-800-824-0524 from 8 am to 5 pm (Eastern Time) for Warranty,
Service or Installation Assistance you may need. Thank you.
Please save and read all safety, operating and installation instructions before
Installing or applying power to your Digital Mobile Charge.
Table Of Contents
Product Overview
page 3
Advantages of the DMC
page 3
Details of Operation
page 4
General Safety Instructions
page 4
Personal Safety Precautions
page 5
Installation Warnings
page 5
Installation / Wiring
page 6
Positioning Battery Type Switch
page 7
Start up and Test Procedure
page 8
Description of LED’s
page 9
page 10
Customer Service and Warranty
page 11
Digital Mobile Charge Overview :
The best way to charge a battery is using a 4 step battery charging curve, which cannot be
achieved from a standard alternator. Additionally a standard alternator cannot output a large
enough charge to power an auxiliary battery bank.
First and foremost, On Board Solutions’ Digital Mobile Charge ensures at all times that the power
required to run the primary system of the vehicle or boat engine is not affected. The engine start
battery is constantly monitored and receives top charging priority. The surplus power created by
fooling the alternator is amplified into a higher voltage by the Digital Mobile Charge and is used to
charge a secondary battery bank using a totally isolated digitally controlled 4 step charging curve.
The engine start battery cannot discharge through this system, even in the event of a unit failure.
In summary, the Digital Mobile Charge provides your extra battery system a charge that is
approximately 5 times faster than could be achieved in using the vehicles alternator. This provides
in-transit charging of extra battery banks and increases the life of the batteries by de-sulphating
them. The Digital Mobile Charge provides the same utility as an advanced regulator, a zero loss
battery isolator, and a 4 step battery charger.
Advantages of the Digital Mobile Charge:
1) Installation: Low Cost and Simple installation. Simply connect the unit to your start battery and
to your additional domestic battery bank.
2) No direct connections to the standard engine alternator, or to the outboard.
The Digital Mobile Charge replaces the need for a battery isolator and an advanced regulator, all
while providing in-transit charging.
3) The Digital Mobile Charge always ensures the engine start battery is maintained and top
charging priority.
4) Multiple Digital Mobile Charge units can be used. For example, if you have a 60 amp
alternator, and 3 battery banks (engine start, domestic bank, and bow thruster) then 2 units can be
used to run the domestic bank and the bow thruster bank. Internal programs will adjust their
charger patterns to accept the second unit, all while ensuring only excess power is used and the
primary start battery is not placed in jeopardy.
5) Ensures there is no voltage rise on the engine management system, eliminating the risk of
alarms or damage to the system.
6) The Digital Mobile Charge isolates both the engine start battery and domestic battery bank,
preventing any feedback through the unit.
Details of Operation:
Digital Mobile Charge begins operation by monitoring the engine start battery. The unit will not
start until the battery voltage exceeds approximately 13 volts for 12V models (26V for 24V
models), then waits for 2.5 minutes to ensure that some charge is placed quickly into the engine
start battery. After that, the Digital Mobile Charge pulls the engine battery down to no less than 13
volts for 12V models (26V for 24V models), which enables the engine battery to still receive a
small charge and ensures the alternator works at its full potential.
Additionally, to further ensure the engine battery is O.K., every 20 minutes the Digital Mobile
Charge stops for 3 minutes, allowing the engine start battery to be charged exclusively by the
alternator. After the 3 minutes, the Digital Mobile Charge resumes battery bank charging by pulling
down the engine start battery to 13 volts for 12V models (26V for 24V models) and so continues
the charging cycle. After a period of time, calculated by the software, when the battery bank
batteries are full, the system will float the batteries at 13.5 volts for 12V models (27V for 24V
models) all while ensuring the viability of the engine battery comes first.
Other features included in this system are an alternator temp sensor, a remote battery temp
sensor and a fully automatic sleep sensor, which switches the unit off when the engine has
General Safety Instructions:
Before connecting your batteries, read all instructions and cautionary markings on
the battery charger and batteries.
CAUTION - To reduce the risk of injury; charge only lead acid type rechargeable batteries
(lead acid, gel cell and AGM). Other types of batteries may burst, causing personal injury.
Use of attachments not recommended or sold by On Board Solutions or Professional
Mariner, LLC may result in a risk of fire, electrical shock or personal injury.
Do not operate the charger if it has received a sharp blow, direct hit of force, dropped or
otherwise damaged in any way.
Do not disassemble the charger. Call the factory directly when service or repair is required.
Incorrect assembly may result in risk of electrical shock or fire.
To reduce risk of battery explosion, follow these instructions and those published by the
Battery manufacturer, and of any equipment you intend to use in the vicinity of a battery.
Review all cautionary markings and labels.
Personal Safety Precautions
1. Someone should be within the range of your voice or close enough to come to
your aid when installing this product or working near lead acid batteries.
2. Wear complete eye protection and protective clothing. Avoid touching eyes while
working on or with batteries. Have plenty of soap and water nearby in case of battery
acid comes in contact with skin, clothing or eyes.
3. If battery acid comes in contact with skin or clothing, wash immediately with soap
and water. If acid enters the eye (s) flood eye (s) with running water for at least 10
minutes and get medical attention immediately.
4. Never smoke or allow a spark or a flame in the vicinity of a battery or engine.
5. Be extra cautious to reduce the risk of dropping a metal tool onto a battery. It may
spark or short-circuit the battery or other electrical parts that may cause an explosion.
6. Remove all personal metal items such as rings, bracelets, necklaces, watches and
jewelry when working near a battery. A battery can produce a short circuit high enough
to weld a ring or any metal, causing serious burns.
Installation WarningsSet the unit as you would any other high power battery charger; fit it near the batteries in a cool, dry and
well-ventilated space to ensure the unit has the ability to dissipate the heat it will generate. Do not place
directly above or below the batteries.
WARNING: Electrical Shock and Fire HazardsOn Board Solutions and ProMariner recommend all wiring is done by qualified personnel. Disconnect all
power sources to prevent accidental shock. It is the installer’s responsibility to ensure compliance with all
the applicable installation codes and regulations.
WARNING: Fire HazardDo not cover or obstruct the ventilation openings. Do not install this equipment in a compartment with
limited airflow; Overheating may result.
WARNING: Low Voltage - Electrical burn and spark hazard. Disconnect battery power before servicing.
WARNING: Be sure the area around the charger and batteries is well ventilated while the batteries
are being charged.
WARNING: Add distilled water in each cell until electrolyte reaches levels specified by the battery
manufacturer. This helps purge excessive gases from cells. Do not overfill. Always carefully follow
manufacturer's recharging instructions.
WARNING: Study all manufacturer’s specific precautions, such as removing or not removing cell
caps while charging, in addition to rates of charge.
WARNING: Clean battery terminals with full eye protection to prevent corrosion from coming in
contact with eyes.
WARNING: If necessary to remove a battery from this charger, always remove grounded terminal
from battery first. Make sure all accessories are off, as to not cause an arc.
Installation of the Digital Mobile Charge:
Wiring: Connect all wiring with fuses removed from wiring fuse holders to protect against accidental
shorting and the units Sleep and an Auto Start feature. If the input voltage (engine start battery) is above 13
volts for 12V models (26V for 24V models), then the unit will auto start. Ensure all wiring is correct before
re-inserting wiring fuses.
Battery Temp Sensor: Simply connect the ring end of one of the enclosed temperature sensor to
a battery terminal post ( negative or positive ) Be sure not to crush the temp sensor which is
enclosed inside the yellow ring terminal, as this will destroy the processor chip. Connect the wire
end of the temp sensor to the connector marked Battery Temp on the Digital Mobile Charge.
Simply push the small lever down and insert one wire into each side. There is no polarity on these
wires. The output voltage will be reduced in the event the battery temperature increases due to
battery failure. If the battery exceeds 50 degrees Celsius, the Digital Mobile Charge will switch off,
as a major battery failure has most likely occurred.
Alternator high temp disengage: This is another supplied temperature sensor which should be
connected to your alternator output post ( b+ ) and will disengage the Digital Mobile Charge in the
event the alternator reaches 100 deg Celsius. A warning LED will illuminate when the alternator
reaches the threshold temperature. When the alternator cools down to 80 degrees Celsius, the
system automatically reengages and continues charging.
Battery Charging Voltage Monitoring: As a standard feature, this unit senses all the control
voltages at the unit. However, if you want to sense the voltage at the domestic battery bank
directly to overcome the voltage drop in the cable run, then simply connect a cable from the
domestic sense connection directly to the domestic battery.
Positioning Battery Type Selector Switch:
Program the battery type into the unit. Do so by positioning the battery type dip switches on the
unit to the appropriate battery type.
There are 4 possible battery type selections:
Non-Sealed Lead Acid Battery (Orange LED)
Exide Gel Battery (Green LED)
Gel Battery (All others except Exide) (No LED)
AGM Battery (Red LED)
Understanding Battery Types
There are three primary types of batteries in the marketplace today; Flooded (Lead Acid), AGM (Absorbed Glass Mat)
and GEL cell (Gelled Electrolyte Lead-Acid). Traditionally, the most common type of batteries used are Flooded (Lead
Acid batteries).
Almost all GEL cell batteries will state that they are GEL cell on the battery case or labels. (Shown below) are typical
battery voltages at absorption and float levels.
Battery Type
Flooded (Lead Acid)
AGM (Absorbed
Glass Mat)
GEL cell
12V Charging
14.6 Absorption,
13.3 Float
14.4 Absorption,
13.3 Float
14.1 Absorption,
13.8 Float
24V Charging
29.2 Absorption,
26.6 Float
28.8 Absorption,
26.6 Float
28.2 Absorption,
27.6 Float
Battery Information
Water filled (with or without
Removable caps)
NOTE: AGM (Absorbed Glass Mat) batteries are not GEL (Gelled Electrolyte Lead-Acid) batteries. AGM
batteries are charged at the same charging profile as Flooded (Lead Acid).
***If you are still unsure as to what kind of battery you have, we recommend that you contact the manufacturer of the
Start-up and Test Procedure:
When the Digital Mobile Charge first starts up, the top battery type LED will illuminate yellow, red,
green, or yellow flashing depending on the battery type selected, and the Fast Charge LED ( 3
down ) will begin flashing slowly. This green LED slow flashes to shows that the unit is working but
is inactive for the first 2.5 min. with the intention of allowing the engine start battery to recover a
After about 2.5 min. the Fast Charge green LED will stop flashing and change to a continuous
green light and the unit will begin charging, or the unit will shut down to rest mode if the battery
voltage is to low. It can do so because the Digital Mobile Charge is constantly sensing the voltage
from the input battery. If the voltage is above 11 volts for 12v models (22 volts for 24v models)
then the system will come on for about 5 min., it will sense that the input battery voltage is to low
to continue and the unit will go into sleep mode.
If your vehicle has a normal / healthy engine start battery, The Digital Mobile Charge will begin
Fast Charging after the initial 2.5 minutes, and that current to the engine start battery will be
provided in addition to the amplified current being provided to the domestic battery bank by the
Digital Mobile Charge. This high current output to the domestic battery bank will continue in cycles
of 20 minutes on and 3 minutes off to ensure the engine start battery is always O.K.
Once the domestic battery bank reaches its charging voltage (depending on the battery type
setting but between 13.5-14v for 12v models or 27v-28v for 24v models), the Absorption LED will
illuminate and the high rate of charging will continue for a period of time calculated by the Digital
Mobile Charge. This time period is determined by what battery type you have selected and the
state of discharge of the domestic battery bank (1-6hrs). The rest period continues to be 3 minutes
off for every 20 minutes off. After the calculated amount of time is over, the unit drops to float with
no switch off period. A Float LED indication tells the operator the domestic battery bank is charged
and is being held at a maintenance voltage.
The Digital Mobile Charge will attempt to hold the battery voltage at the above described Float
range. If current is demanded, the Digital Mobile Charge will try to meet that demand and keep the
domestic battery bank at float. However, if the domestic battery bank falls below approximately
12.8v for 12v models (25.6v for 24v models) for more than 15 minutes, the system will reset into
the Fast Charging mode again. Additionally, if the input voltage falls below 12.8v for 12v models
(25.6v for 24v models) the unit will assume that the input is switched off and will switch the system
into rest mode to conserve energy. Only if the input voltage rises again, by running the engine
again for example, will the system restart.
If on start up nothing happens, be sure to test the battery voltage. It should be above 11 volts for
12v models (22 volts for 24v models), to see the unit working, start up the engine and ensure you
are getting at least 13.5vdc for 12v models (27v for 24vdc models) at the battery.
Description of LED’s found on Unit:
1) BATTERY TYPE- Tri Colored LED: This simply displays the battery type that the user has set the Battery Type
Switch to:
Non-Sealed Lead Acid Battery (Orange LED)
Exide Gel Battery (Green LED)
Gel Battery (All others except Exide) (No LED)
AGM Battery (Red LED)
2) ALTERNATOR TEMP- Yellow: This monitors the temperature of the alternator and disengages the unit in the
event of the alternator reaching 100 deg C, which waits for the alternator to cool down then automatically re-engages.
3) FAST CHARGE: Green: This should be on from start up (slow flash shows unit is on but on rest mode for the first
2.5 minutes upon start-up and approx. every 20 min after) and shows that the alternator should be working at it's
maximum. This LED should remain on until the Float Mode LED comes on and signals the high charge rate is
4) ABSORPTION CHARGE: Yellow: Timer Activated: This LED comes on when the voltage reaches about 13.9 14 volts (27.8v – 28v for 24v models). The software will calculate the timing for the Absorption Charge and
depending on how long it took to turn on, will dictate how long the timing cycle will remain on. This will vary from
1 - 6 hours. This light will remain on until the Absorption Charge is over.
5) FLOAT MODE: Green Float Mode LED: This indicates that Absorption charge cycles are now over and should
remain on after all the high charge lights are out. The system is now running at a maintenance charge rate of
approximately 14 volts for 12v models or (28v for 24v models) at the battery.
6) HIGH INPUT VOLTAGE: This LED will warn you of high input voltage and switch off the Digital Mobile
Charger charging output. Specifically, this LED means that your alternators own regulator may have failed and the
alternator can now run unregulated, possibly damaging your batteries.
7) LOW INPUT VOLTAGE: Yellow: Low Voltage Warning: This is simply saying that there is low voltage at the
main battery bank and has no active function. For information only, this usually indicates a defective alternator, or
perhaps a defective main battery.
8) HIGH OUTPUT VOLTAGE: This LED will warn you and switch off the charging. This LED indicates that
either the Digital Mobile Charge may have failed and was in the process of overcharging your battery bank, or you
have some other charging source on your output battery bank which is overcharging the batteries and the Digital
Mobile Charge thinks it is our unit.
9) LOW OUTPUT VOLTAGE: Yellow: Low Voltage Warning: This is simply saying that there is low voltage at
the output battery bank and that the unit is unable to keep up with your demand on the battery bank, or the unit has
failed and is not working.
10) HIGH BATTERY TEMP: Red: This LED shows that the battery temperature sensor has picked up a
temperature in excess of 50 deg C at its source ( where ever you have fitted it ) this will trip the unit until it has been
11) CHARGER OVER TEMP: Yellow: This device monitors both heat sinks and in the event of that exceeding 75
deg C the unit will switch off until the temperature has been reduced. It is important not to install the Digital Mobile
Charge inside a small hot engine room.
12) UNIT FAILURE: Red: This LED will give an indication in the event of a total unit failure.
Pre set voltages
Minimum input voltage the unit will run at: 13 volts for 12v models (26v for 24v models)
Voltage the unit switches off and drops into sleep mode: below 12.8 v for at least 15 minutes
(25.6v for 24v models)
Power consumption on sleep mode: 5 ma
Max input voltage trip: 15.5V (31V for 24V models)
Max output voltage trip: 15.5V (31V for 24V models)
All voltages refer to a default temperature of 20 deg C. If the battery temperature sensor is
used, these voltages will vary with the battery temperature, as the Digital Mobile Charge
takes this into account.
Alternator temp disengage: 100 deg C
Reset Alternator:
80 deg C
Battery temp trip:
50 deg C
Heat sink trip:
70 deg C
Heat sink reset:
60 deg C
Low battery alarm:
12.5V (25v for 24v models)
Low battery regulation:
13V (26v for 24v models)
High battery voltage trip:
15.5V (31v for 24v models)
Max input current at:
12V = 45 amps
Amp meter +/- 10%
Voltmeter +/- 1%
Customer Service & Warranty:
We are committed to customer satisfaction and value your business. If at any time during the
warranty period you experience a problem with your new Digital Mobile Charge, simply call us at
1-800-824-0524 during standard business hours (8:30 AM – 5 PM Eastern Time) for Technical
Each product is guaranteed against defects in material and workmanship to the original consumer in normal use for
two full years from the date of purchase. On Board Solutions and Professional Mariner, LLC at its discretion, will
repair or replace free of charge any defects in material or workmanship. The following conditions apply:
• Warranty is calculated from date of manufacture if not registered within two weeks of sale.
• Warranty void if damage occurs due to negligent repairs.
• Customer is responsible for returning the product to On Board Solutions and Professional
Mariner, LLC. Inbound shipping costs must be prepaid.
• This warranty does not cover blemishes due to normal wear and tear or damages caused
by accidents, abuse alterations or misuse.
Purchase or other acceptance of the product shall be on the condition and agreement that On Board Solutions and
(Some states do not allow the exclusion or limitation of consequential damages, so the above limitations may not
apply to you.) This warranty is made in lieu of all other obligations or liabilities on the part of Onboard Solutions and
Professional Mariner. Additionally, On Board Solutions and Professional Mariner neither assumes nor authorizes any
person for any obligation or liability in connection with the sale of this product.
To make a claim under warranty, call Factory Service at 1-800-824-0524. Follow the company’s return policy, which
will be provided by the company. On Board Solutions and Professional Mariner will make its best effort to repair or
replace the product, if found to be defective within the terms of the warranty, within 30 days after return of the product
to the company. On Board Solutions and Professional Mariner will ship the repaired or replaced product back to the
Please contact Customer Service for additional assistance. This warranty provides to you specific legal rights and you
may also have other rights, which vary from state to state. This warranty is in lieu of all other, expressed or implied.
OBS & Professional Mariner, LLC.
Factory Service Center
Service Phone: 1-800-824-0524
200 International Drive, Suite 195
Portsmouth, NH 03801
Phone: (603) 433-4440
Fax: (603) 433-4442
Visit us on the web at:
Please Register your product with the enclosed warranty card, or online at
Was this manual useful for you? yes no
Thank you for your participation!

* Your assessment is very important for improving the work of artificial intelligence, which forms the content of this project

Download PDF