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Battery Chargers 12V & 24V

Pro Budget. Digital Battery Charger Range

12Volt 6-20Amp

24Volt 7-12Amp

This new compact design, low cost, switch mode, 4 step, constant current, single output battery charger range is designed for use where only a single battery bank is to be charged. After the battery is charged the unit drops to a safe float voltage and the unit will act as a power pack, safely delivering power to feed any on board power requirements up to a maximum current of the charger. Due to reverse polarity protection of this unit, a battery must be connected to the charger a minimal charge in the battery before the charger will activate, or becomes a power pack.

This charger is extremely compact, and is preset so it can be used for open lead acid, sealed lead acid, gel etc., or any battery where the charger voltage should not exceed 14.4 volts (see charger voltage specification and performance chart below).
12Volt 6 Amp 12 and 24Volt 7, 12 and 20 Amp
Model: Part number PB12V6A PB12V10A PB12V20A PB24V7A PB24V12A
Input voltage = AC 100-240V 47-63Hz Yes Yes Yes Yes Yes
Output Voltage
High Charge Voltage 14.4V max 14.4V max 14.4V max 28.8V max 29.8V max
Float Voltage 13.6V 13.6V 13.6V 27.2V 27.2V
Efficiency 87% 87% 87% 87% 87%
Reverse Polarity Protected Yes Yes Yes Yes Yes
Short Circuit Protected Yes Yes Yes Yes Yes
Overload Protected Yes Yes Yes Yes Yes
Over Temperature Protected Yes Yes Yes Yes Yes
Thermostatically Control Cooling Fan Yes Yes Yes Yes Yes
Charge Cycle and Protection Indicator
LED red=power on green=float charge yellow=high charge Yes Yes Yes Yes Yes
LCD No Yes Yes Yes Yes
Meter, (needle type) Yes No No No No
Size mm (width height depth) 70 x 48 x 155 103 x 50 x 167 115 x 60 x 167 103 x 50 x 167 115 x 60 x 186
Weight KG 0.5 0.9 0.9 0.9 0.9
Accessories, Euro and English Cable No Yes Yes Yes Yes
Order Code MLE00151 MLE00152 MLE00153 MLE00154 MLE00155

Pro-Sport. Water Proof Battery Charger
Totally Water Proof (IP68)
Twin Totally Isolated Outputs (2 x 12Volts or 1 x 24Volts)
12Volt 8-20Amp 24Volt 4-10Amps
Extruded Aluminium Housing Fully encapsulated to meet toughest water proofing standard (IP68). 

Both positive and negative fully isolated, this enables the unit to charge 12 or 24 volt lead acid / Gel Battery Selectable. Dynamic Thermal Output Control, LED Power and Charge indicators, Built-in Protection, Distributed-on-demand, 4 step charging curve, Pre-wired water proof loom for easy installation.

Advice: It is recommended to use waterproof battery chargers where the water proof aspect is a priority. For all other applications Sterling recommend the digital control units (LINK???) which are lighter and have superior performance.

Ideal for sports boats or equipment where the charger will be exposed to wash down such as a power hose.

Water Proof Battery Chargers
Totally Isolated Outputs

DC Volts Amps Output Voltages Mains supply Hertz Size Weight Order Code  
12 & 24 8 2 x 12V or 1 x 24V 180-230V 30-80Hz 170 x 180 x 65mm 3.8KG MLE00156  
12 & 24 12 2 x 12V or 1 x 24V 180-230V 30-80Hz 210 x 180 x 65mm 4.5KG MLE00157  
12 & 24 20 2 x 12V or 1 x 24V 180-230V 30-80Hz 270 x 180 x 65mm 5.0KG MLE00158  


Automatic 4 step battery charger  International

The extremely successful 4 step battery chargers (analogue type) fall into the following ranges.

Small (International Range)

This Charger offers all the features of the Medium and has proved to be one of the most successful on the market due to its price, extremely small footprint, and performance. This 3 output unit has multi input voltage (80V-300V) multi input frequency (40Hz-400Hz) and is ideal for the 15-25 ft boat range.

Medium (International Range)

This new range of chargers is made for the international boater. They offer
many new functions to ensure that they may be used anywhere in the world.
Specially designed with the boat builder in mind, they have the following
features as standard: these extra features make the Sterling range the most
versatile at the lowest cost possible.

1) 4 step battery charging
2) Programmable for gel, open lead acid, sealed, maintenance free batteries and battery bank sizes
3) Automatic 110 / 230 volt crossover
4) Power pack functions
5) 3 isolated outputs
6) Low cost, high performance
7) New 3 stage R.F.I. filter for even lower radio interference
8) Twin fan cooling for maximum performance in hot ambient temperatures


4 Step Constant Current Small Range Battery Chargers
DC Volts Amps Mains Hertz Size Weight Order Code  
12V 10A 230V 50Htz 240 x 145 x 60mm 1.5Kg MLE00084  
12V 20A 230V 50Htz 240 x 145 x 60mm 1.8Kg MLE00095  
24V 15A 230V 50Htz 240 x 145 x 60mm 2.5Kg MLE00101  

Automatic 4 step battery charger - Pro Digital

The new DIGITAL ranges of battery chargers are the latest High Tech up grade on the above battery chargers. All the power benefits of the standard system are retained but the control, safety and information aspects have been upgraded beyond recognition. The latest benefits offered by digital control system are highlighted in the Quick Check on the opposite page and should be studied. Digital control ensures more accurate control, more battery information type storage in the software and more real time calculations to be done to ensure the best charge. More information is also available in the control chip which can then be displayed on the new remote control and information panel which is supplied as a optional in the small range but as standard in the large range. 



4 Step Constant Current Medium Range Battery Chargers
DC Volts Amps Mains Hertz Size Weight Code  
12V 30A 230V 50Htz 300 x 170 x 60mm 2.5Kg MLE00105  
12V 40A 230V 50Htz 300 x 170 x 60mm 2.5Kg MLE00112  
12V 50A 230V 50Htz 300 x 170 x 60mm 3.0Kg MLE00119  
This remote control is an optional extra for the above three chargers 99.00 (Plus S&H)


Best Buy Winner
from Seglen
German yacht magazine test
Digital software control
There are 2 ways to control electronic processing, Analogue (hardware control) and Digital (soft ware control). Hardware control is where the voltage sensing and processing are all done via transistors and electronic hardware. This is fine as long as the information to be processed is kept simple. However an Advanced Regulator may look simple (and most of them are) but when all the different battery types, bank sizes, and safety parameters are installed, the unit would become almost impossible to make and set up. Sterling leads the field in this type of controller but has found that when upgrading from our previous model that it required so many extra features to keep up with new battery types and alternator types etc that it made a hard ware version impossible to make.
Digital control (software): This uses computer lines of code, digitally burned into a memory processor in the Advanced Regulator. This means that very complex information and mathematical processes can be processed, which would be impossible for the hardware system to do. It is the next generation of control, and more and more you will see the term digital control appearing on different products. Digital control offers so many extra features at no extra cost (see below) and accuracy beyond the ability of the analogue version.


3 isolated outputs:
The charger has 3 outputs enabling 3 different battery banks to be monitored and charged at the same time.
Automatic 110/230 volt selector:
The in-built system enables the charger to be automatically used on a wide voltage range from 80-300 volts A/C. This covers all the possibilities encountered on any marine in the world.
Multiple input frequencies from 40-400 Hz:
Self-explanatory, the unit is able to work on all worldwide A/C input frequencies.
Thermostatically controlled fan cooling:
The digital software monitors the unit temperature and controls the fans; this reduces any unnecessary fan noise from the charger and prolongs the fans life for many years.
High ambient temperature rated:
Many boat builders expect the chargers to work at full power continuously at 40 deg ambient, few chargers in the world meet this specification - Sterling's do.
3 battery type charging curve selector:
There is more than one battery type; most chargers do not offer different programs for different battery types. Failure to offer an option will result in either overcharging some battery types and sulphating others. The Sterling offers charging curves for open lead acid batteries, traction batteries, sealed batteries, gel batteries and A.G.M batteries.
Automatic battery bank size and state:
No need to program in the battery bank size as the digital software can work that out itself.
Automatic High Charge timer calculated every time:
Most chargers have a fixed high charger timer, which works regardless of battery size and state or even load on the boat. The digital processor is able to discern the battery bank size, what state it is in and even take into consideration the power used by the boat. It then calculates the ideal equalizing charger time; this will be different every time and will be from 1-6 hrs
Automatic 7 day de-sulphation cycle:
The good thing about a constant current charger is that it de-sulphates the battery plates ensuring maximum life from the batteries. However, this only works if the charger is switched on/off regularly (i.e. every time you disconnect and reconnect the charger the plates are subjected to a de-sulphation cycle). The problem is some boats or standby equipment may be rarely used. For example, a boat could be moored all year and never leave the pontoon, or a stand by generator with the charger on all the time. In these cases the de-sulphation cycle would only happen once and the batteries would eventually sulphate causing premature destruction. However the Sterling software has a 7 day timer which in the event of inactivity will automatically run a de-sulphation cycle keeping your plates clean.
3 stage R.F.I filter:
In order to meet C.E. requirements for Radio Frequency Interference a three-stage filter is used to ensure that not only is the standard reached but also that we fall well above the standard legally required.
Battery temperature sensing and compensation:
The Sterling Digital comes complete with a battery temperature sensor, which is automatically set to one of the temperature compensation set by your battery type selector switch.
3 battery temperature sensors:
The larger battery charger range comes complete with 3 temperature sensors, which monitor and display and react to the 3 different battery banks, including 3 high temp trips.
Independent unlimited high battery temp trip circuit:
 This unit has a trip circuit which can be connected to any trip device such as temperature trips or any trip which results in an open circuit. The problem is that a charger could be attached to 10 batteries but only monitoring 3. However if you wish you can put a standard temperature trip on every battery and link them together into a common trip circuit. If any of these batteries exceed a pre determined value the charger will switch off.
High battery voltage trip:
Things do go wrong no matter how hard we try so in the event of the regulator control failing, then any voltage above what the software is expecting will shut the battery charger down and display the fault.
High battery temperature trip:
It is amazing how many companies sense battery temperature and compensate the charger voltage against temperature. Yet in the extreme event of total battery failure and the battery is going to boil the battery charger will not switch off the charger. The Sterling processor not only senses the temperature but will shut down the charger in event of total failure and display the fault condition.
High heat sink temp trip:
In the event of extreme temperature or cooling fan failure the battery charger will switch off at 70 deg C
Auto Power reduction in event of high temperature.
Because it is best to get as much power as possible at high temperature, in extreme high temperature or cooling fan failure, if the heat sink reaches 65 deg C then the output current of the unit will be systematically reduced to prevent the high temperature trip being activated at 70 deg C.
7 led output display information panel: High charger rate, timer activated, battery type (3 colours), Float mode, high battery temp trip, over voltage trip,

24kt gold plated output terminal posts:
Over a period of time brass corrodes in salt air making poor connectors. We have all seen the green paste that forms around battery terminals etc. All Sterling connection posts are solid brass and are 24kt gold plated to eliminate this for life.
Negative Fused externally (A.B.Y.C requirement):
Because the largest market for our products is in the USA, it is important to conform to European and USA standards. This is a requirement for the USA  A.B.Y.C boat building code of practice. As a result some electricians were receiving electric shocks because they thought they were on the D/C negative system when they were on the 110V A/C system. As a result international regulation bodies are attempting to change the colour of the D/C negative cables (which have been black) to yellow, this is already the case in the U.S.A. for A.B.Y.C. and is under review in the U.K. The negative cable in the new digital range comes as yellow and a gold fuse is supplied.
Reverse polarity protected:
The supplied fuse blocks offers a good reverse polarity protection system.
Overload protected:
As stated the unit cannot be overloaded.
Short circuit protected:
As stated the cant can be short-circuited with no adverse results.
Remote control socket:
The unit has the ability to be connected to a digital L.C.D. information and control panel.
Sturdy construction:
The unit is made from extruded aluminium and extremely sturdy, with extra thick 2.4 mm printed circuit board.
Small footprint:
A modern requirement even on the largest boats is the requirement for a small foot print size, check our size out.
 Extra features when connected to the Digital remote control.
Remote switch on/off:
Manual power reduction selector:
Some marinas offer only limited shore power; as a result high power battery chargers will not work. It therefore becomes necessary to reduce the out power of the charger to enable it to operate from the shore power. This remote offers the ability to select 100%, 50% or 25% power to deal with the lowest shore power supplies. It's best to have some power rather than none. This feature is also good if an onboard generator is used, i.e. you may want say a 100 amp charger for the onboard generator to charge the batteries fast but the local berth cannot support such a large charger. In this case the charger could be reduced to 25 amps when returned to the marina berth.
Auto memory power lock on setting:
If reduced power is selected the software remembers the setting so in the event of removing the shore power the charger will start up on the reduced setting next time.
Delay start up to enable power setting change:
In the event of a boat entering a marina and only a low power supply is available, if the last time the charger was used, then the charger would start up on high power and trip the shore supply. To overcome this problem when the charger is started, the software counts down 30 seconds before automatically starting the charger on the last setting. This gives the operator ample time to reduce the power if required on the remote control.
2 line 16 bit L.C.D. display screen:
As described above a large information screen is used which has an on/off switch for the background light.
Auto cycle all information with manual screen lock:
Due to the large amount of information being displayed, it is not possible to fit it all on the screen. As a result the screen automatically scrolls through the screens. However you may wish to monitor one screen in particular, in this case simply push the lock button to lock that screen on.
Impressive information displayed:
The L.C.D. display and control gives the following information, charger amps, charger volts, time remaining on equalizing charger, battery type selected, battery temperature, charger temperature, plus all alarm and other control functions.
Surface mount or recess box:
The clever remote control box design means the box can either be surface mounted on a bulkhead or flush mounted.