electrical requirements onboard caravans have increased in the modern
world (laptops / tablets / phones/microwaves/hairdryers / Caravan
movers etc.). When at campsites this is no problem thanks to AC
hookup. However, if touring is your forte and don't wish the extra
cost and limitations at campsites, or simply unable to operate
you fridge and charge you caravan / mover battery due to the new euro
6 engines then this is the product for you.
existing charging off onboard caravans batteries from your main
vehicle while in motion is historically terrible. This is because the
onboard charging systems have not modernised by keeping up with
onboard electrical demands NOR by dealing with the contemporary
peculiarities associated with Euro 5 / Euro 6 + engines. A prime
example being that some fridges simply do not work whilst towing your
caravan and the ability to actually charge the onboard battery is
simply out off the question. This is because the towing vehicle
alternator’s voltage is dropping below the enabling threshold of
the fridge and below that required to charge a batteries. Refer to
page 15 for Euro 6 / regenerative braking information. We use a van
in the test - any modern SUV or car could have also been used. This
also drastically effects the performance off the caravan mover
rendering this expensive and useful product virtually unless
problems are totally unnecessary when you consider that modern
vehicles have such large alternators and surplus power - much more
than their predecessors. Utilizing the alternator’s potential to
actually charge your caravan battery fast and fully + running your
fridge could free you from constant visits to camp sites when the
Wildside option could be enjoyed more and save a lot off money.
full caravan battery means freedom to enjoy the Wildside experience
and allow the installation of more power hungry products such as
inverters . Increasing battery banks sizes extends this experience
with the knowledge that during your next drive your battery will
fully charge from your vehicle. This is something caravanners always
assume their system was doing, yet it simply was not.
bias mode (default).
absorption fridges are very inefficient, they waste a lot of valuable
power that could be used to charge your domestic battery / mover
battery. Out of the 18A being supplied by the BBC, 13A may be being
used for running the fridge, leaving only 5A for charging. Fridges
really only needs to be powered 50% of the time to retain their
chill. In battery bias mode, we initially focus all the BBC’s power
to charge the domestic battery, for 15 minutes (fridge line
disengaged). If your domestic battery is nearly full (or full) this
time shall be much less. After the 15 minutes (or less), the fridge
will come online whilst charging your domestic battery (albeit at a
lower rate). The fridge shall come on and remain on provided the
domestic battery’s charge level is kept high. If, when the fridge
is online and/or the demand from the fridge or a domestic battery
load exceeds what the BBC can supply (e.g. 20A+) then the BBC shall
prematurely go back to solely charging the domestic battery, thus
disconnecting the fridge line. This 15 minutes on and off cycling
shall continue thereafter. The ‘fridge relay engaged’ LED shall
light when the fridge is online, shall be off during sole domestic
Summary - BBC initially charges solely the domestic
battery for 15 minutes or until nearly full. The fridge line is then
brought online, whilst maintaining charge to domestic. The fridge
remains online indefinitely provided the domestic battery capacity is
kept high (14V+). The proviso is that the fridge load does not exceed
that of what the BBC can provide. If it does a 15 minute timer begins
- then the domestic battery gets sole charge and so on and so forth.
Therefore, provided the domestic battery is kept topped up the fridge
shall remain online throughout the duration of the trip. If you find
that your fridge comes online then trips immediately our algorithm
has deemed that the domestic battery has not had sufficient charge,
please wait up to another 15 minutes.
bias mode (press both SETUP and SELECT buttons together for 10 - 30
seconds to engage)
you want your fridge operating constantly from the BBC supply, then
put the BBC into fridge bias mode. The fridge line is constantly
online, any surplus current shall be directed to charge up your
domestic battery. The ‘fridge relay engaged’ LED shall be on
solid as the fridge shall be online. To restore battery bias mode
press and hold both buttons down for 10-30 seconds (i.e. repeat
Analysing the graphs.
First of all I
would like to make very clear that this is the absolute best
performance you will get. Bear in mind, with this cable I have not
added all the plugs, relays and poor connections associated with this
circuit on your vehicle for the fridge etc. So, you could only expect
lesser performance. Also, the neg was a copper neg return where a lot
of people fit the neg to chassis which will make the figures even
worse again. So, the above is the best case you can expect, not even
the average. The 2 areas to note are the green and purple, the green
is the voltage where you need to be to have any chance of charging
your caravan battery. The higher up the green area the better your
battery charge will be. The purple is your battery depletion, the
lower down you are on this the more power you have used and so the
more "empty " your battery will become.
The euro 6 +
with re-gen breaking vehicles are the most telling. When they are on
their low voltage setting ( designed to deplete the engine starter
battery about 20% ) they already start out in the battery discharge
voltage ( it’s meant to ). However, the voltage which ends up in
the caravan under load is way below this due to the voltage
drops in the cables. This means your fridge is receiving a very low
voltages and it simply cannot operate in the voltage range.
simple fact off the matter is that with a euro 6 tow vehicle on a
caravan will not work the fridge or charge the battery rendering the
caravan feed system not functional and totally unless, there is
simply no point in having any connection at all .
solution: the voltage drop down the cabling from the vehicle to the
caravan is unavoidable. Also, with new tow vehicles (with euro 6
engines plus) this already poor performance is compounded by
the fluctuations between the low 12.6V to high up in the 16V+ region
( highest so far is about 18 V ) .
You may be wondering why,
when my fridge, which may be rated at 10A at 12V would be interested
in the 12A or 22A graphs. The answer is in the maths. Your fridge may
be rated at 10A at 12V = 10 x 14V = 140W. However, when your voltage
has dropped to 8.5V (worst case as above) then the fridge power at
120W the maths changes - so 140 W = 16.5 A x 8.5V. Therefore,
the amps required is now 16.5 A (also note your fridge would simply
not run at this low voltage). What the Sterling Wildside does is to
take the low input voltage and current but transform the power from
low voltage useless power to much higher voltage useful power. The
unit also as a build in 4 step digital constant current programable
battery charging system as well as the fridge operation It also
reduces the voltages in the event of the re-gen braking high voltage
phase attempting to damage any equipment in the caravan. This allows
not only your fridge to work but also very effectively charges your
battery (better than even the conventional systems).
above figures are based on a absorption fridge, where ever possible
if you want to do a lot off wild side camping you must never use
absorptions fridges as their power consumption is insanely
higher than a compressor fridge, a typical absorption fridge would
have a constant 14 amp draw where as a compressor fridge would
average 2 amps hrs
The Sterling system can no longer to
be seen as a luxury for increasing the performance of your caravan
electrical system but for Euro 6 Plus engines it has now slipped into
the category of no Sterling no fridge or Caravan off-site.
solution needs to overcome the following problems:
1) Deal with
the massive voltage drop down the cables / plugs between the car and
the caravan by boosting the low voltage to the correct voltage
expected to charge the batteries. Also, reducing the voltage during
the voltage highs associated with the new euro 5-6+ engines to
prevent damage to equipment.
2) Utilize as much of the standard
plug and wiring system as possible to avoid changing the basic system
- for the sake of ease of installation.
3) Enable the fridge
to operate ( 12V aspect ), in transit, or remain ( optional setting )
in operation if not connected to 230V.
4) Charge the onboard
batteries fast using a 4 stage charging profile + 9 battery type
programmes available. This ensures the battery is fully charged.
Plus, a custom set option allowing the unit to be set up to any
customer’s personal choice. This ensures your electric caravan
mover works when you arrive at your destination.
5) Present the
owner with a financial ‘payback’ from the product’s
installation. Campsite savings + battery longevity.
6) Supply easy
option modes to cover DC fridges, touring or site modes.
Add extra safety features, such as: Low battery fridge disconnect to
allow lights to work after fridge has been disconnected in the event
of battery discharge.
1) A clean and simple install in
the main charging cable via the conventional socket. The conventional
socket is rated to about 20A, however, it is more like 2-3A. The
addition of the 20A battery to battery charger (BBC1225) will
dramatically increase that charge rate and shall also compensate for
all the problems associated with euro 5-6+ engines. Likewise, if you
don't have Euro 5-6+ you will still enjoy at least a 500-700% faster
charge rate and double your useful battery storage capacity. This
constant current charger also enables the battery plates to stay much
cleaner and last longer.
Mode select options
for 12V / 230V fridges and 12V only fridge.
(AC 230V not available) allows the 12V aspect of the fridge to be
engaged directly to the battery when the car has been stopped. This
allows the fridge to run directly from the caravan battery on 12V.
This obviously increases the battery consumption, however, the
battery should be good for a day or so depending on the efficiency of
the fridge. A larger battery bank can be installed in the caravan but
watch chassis weight restrictions. A low voltage battery trip will
disengage the fridge when the caravan battery is low, at approx.
Camp site mode (AC 230VAC available), this only allows
the 12V fridge to operate during transit and will automatically
isolate the fridge from the caravan battery when the journey is
completed. The fridge should then be connected to the 230V campsite
power, to which is can receive its power from.
increasing your battery capacity and charging rate you can then start
looking at inverters. These enable use of phone / tablet charging,
microwaves, hair dryers, hair straighteners, tools etc. Please look
at our new Pro Combi S+ 1600 pure sine wave inverter / charger. Ideal
for adding that next level of comfort to your caravanning experience.
click on this link for more product information
click on this link for wiring information