CLEARANCE - 30 DAYS WARRANTY Battery to Battery Chargers (12V-12V 50A input) or (12V-24V 50A input) 30 Days Warranty Only

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Battery to Battery Chargers  (12V-24V 50A input)

30 Days Warranty Only


BB122450 - Brand New


Installation Manual PDF

Product Information PDF

 30 Days Warranty Only 



This increasingly popular device has a massive amount of applications never before undertaken, from charging your caravan battery, golf trolley, while driving along in your car, to charging large battery banks in lorries or boats.  The key thing about this product is the ease of installation and the fact it does not work nor change anything on the standard engine / vehicle system and as such does not raise any warranty or installation issues.  Fully programmable for different battery types.

Why do I need the DC adaptive battery charger?

By now you will appreciate that the best way to charge a battery is using a 4 step battery charging curve (that cannot be achieved from a standard alternator).  This system enables one to simply attatch the unit to a standard engine battery and it will fool the alternator into working at its maximum ability and ensure all its surplus power is used to charge the auxiliary battery bank to its maximum.  This system is designed to use only the surplus power and ensures that at all times the power required to run the primary system (hte vehicle or the boat engine) is not affected.  The surplus power is converted to a higher voltage and used to charge a secondary battery bank using a digitally controlled programmable 4 step charging curve as per all the other high charge products Sterling makes.

What performance improvements would I expect?

In a nutshell, it charges your extra battery system about 5 times faster than it would otherwise charge.  However, in the case of things like caravans, this could easily increase 20 fold.  The also at least doubles the useful power subsequently available and increases battery life by de-sulphating them.  For best effect, use open lead batteries, avoid gel, sealed and AGM batteries.

Advantages of this unit:

Installation: It does not get any easier, simply connect to your starter batteries and to your domestic battery.  Job done, makes for easy and low cost installation. No direct connections to the standard engine alternator: or to the outboard (if used on an outboard), thus on new installations there is no extra wiring for a split charge system.
Ensure the battery system is not interfered with. Multiple units can be used: for example, if you have a 60A alternator and 3 battery banks (engine, domestic and bow thruster) then two of these can be used to run the bow thruster and the domestic system.  the internal programmes will adjust their charge patterns to accept the other unit and ensure only the excess power is used and the primary system is not placed in jeopardy.
Ensures there is no voltage rise on the engine management system: to ensure no alarms nor damage to the system, be it an outboard, a car, a boat or a camper van. No vehicle warranty issues: as you are not conected to the main system.


How does it work?

The unit monitors the engine start battery, the unit will not start until the battery voltage exceeds 13V, then it waits for 150 seconds.  This ensures that some charge is replaced after engine start.  It then pulls the engine battery down to no less than 13.3V, this enables the engine battery to still receive a charge and ensures the alternator works at its full potential.  This further ensures the engine battery is ok.  Other features included in this system are remote control option, alternator temperature sensing (for larger models), battery temperature sensing, ignition feed (if required), automatic start and shutdown.

Voltage reduction: (new external fan model only) another major key advantage of this unit is that not only can it boost the voltage up on the output but it can also reduce the voltage on the output, (so why do I need this feature?) the truth is that in most applications you do not, however on some modern engines, due to the introduction of calcium batteries, the alternator manufacturers have increased the standard regulators' voltage to punch through the calcium in the batteries.  There are now many alternators fitted with exceptionally high output voltages, for example, there are some common (on boats) Hitachi alternators which are fitted with regulators which are 14.6V +/- 0.2V, we have certainly seen these alternators produce up to 14.8V and we have seen some car alternators reach 15V on first start up, this is great if you have open lead acid batteries but fatal to an AGM, gel or sealed battery, so in this case, it is necessary not to boost the voltage of the alternator but to reduce its voltage.  This new generation of battery to battery chargers do both, so, in effect we do not care what the alternator voltage is, it can be between 13.5V - 15V we will deliver the correct charge and float voltage to your expensive domestic battery bank.