100 | 4WDTouringAustraliaSUN WORSHIP
PEDDLE POWER
REAL WORLD
12V ADVICE10 essential tips to harness the power of the sun
echnology in recent years has seen solar become so popular that it’s rare to see a touring set up that does not have a
solar system of some type propped up alongside the vehicle. The performance of solar panels varies depending on the
temperature and intensity of the light that falls on them.
There is a vital link between the panel and the battery that we are aiming to recharge. This important component is the solar
regulator. So what is a solar regulator and why do you need it, and which best suits your needs and your budget?STUART PEDDLEYou may come across some very small
solar panels that do not require regulators,
these are generally capable of producing
less than 10 – 15 Watts of power, and if
used on an automotive battery, the panel is
too weak to actually push the battery above
a level that could damage it.
These smaller power panels are mainly
used to cover the self-discharge of a battery
so it does not go at during long standby
periods. When producing higher power
levels however, an unregulated solar panel
could push the battery voltage much higher
than it is designed to be charged at and will
cause irreversible damage to the battery
and it will likely look more like a football
before long!
The solar regulator must be able to con-
trol the voltage from the panel effectively
no matter what the level of power that is be-
ing produced by the panel, given its current
operating condition. So the correct size
regulator needs to be selected for the ex-
pected power output from the solar system.
I n short, the role of the regulator is to
control the voltage level being applied to
the battery and to recharge the battery as
the manufacturer intended. This regula-
tion is achieved by two different methods
depending on the type of technology in-corporated into the product being used.
These two different methods are known
as Pulse Width Modulation (PWM) and
Maximum Power Point Tracking (MPPT).
Pulse Width Modulation is an ‘on and
off’ output that is used in many automo-
tive applications, from sensors on rotat-
ing engine parts, through to actuators
such as engine idle speed controllers
and electric brake systems. This repeated
switching has the effect of limiting current
and voltage between two components,
such as a solar panel and a battery.
A PWM regulator simply connects the
solar panel directly to the battery, which in
turn brings the solar panel voltage to the
same level as the battery. When the bat-
tery voltage reaches the right level, the
regulator begins switching the panel on
and off (connecting and disconnecting it
from the battery), to limit the power trans-
ferred to the battery.
Maximum Power Point Tracking regulators
on the other hand can be likened to a voltage
converter. The regulator actually simulates
a load to the panel to keep the panel at
its best performing point. This point will
continually change based on the changes in
the conditions, and the regulator will track
this point and hold it at this level.A MPPT regulator will outperform a PWM
regulator in extracting more power from the
same panel. PWM regulator technology is
less expensive to manufacture and therefore
a lower cost product, and MPPT are more
expensive to design and manufacture.
If the solar system you are setting
up is small and you are trying to work
to a budget, then a good quality PWM
regulator can be an affordable option and
will still do a good job of safely charg-
ing your battery. If you have a large solar
array and battery bank to be supplied, then
MPPT is de nitely the way to go.
The REDARC SRPA range of PWM
regulators feature a multistage, three
selectable battery type charging algorithm
and genuine Anderson plug connections,
all at a reasonable price.
REDARC In-Vehicle Battery Chargers and
Manager chargers all incorporate advanced
MPPT technology and can extract the most
available power from your solar panels,
additional to their other great features
such as DCDC multistage charging and
battery isolation, that makes them great
value for money. For more information on
how to setup your solar system head to
http://www.redarc.com.auT