G'day guys I've just finished installing a dual battery system and DC DC charger into
the back of the ute here so I thought I'd take the opportunity to run you through how it works
and the basics in part one I'll start with the basics of your vehicle's 12-volt system why you
need a dual battery what everyone gets wrong and why it's important to plan your build from
the start so you don't waste time and money I'll show you how to put together a 12-volt
system that's ideal for overnight or long weekend camping adventures that'll let you
run your fridge and camp lights and charge your phones while camping in part two I'll take it
to the next level by showing you how to keep your battery charged while you're on the move
with various vehicle based battery charging options I'll talk about the different types
of 12-volt battery Isolators of charges including the latest in battery charging
technology that'll have your camping better and for longer in part three I'll take it up
a notch again and show you that you don't have to spend a fortune to get an ultimate off-grid
12-volt system with this setup you'll never have to turn your fridge off again you'll have all the
comforts of home with you anytime you can and you'll be set to camp for as long as you want
even permanently I've got some tips tricks and troubleshooting ideas for if you're setting up
your own system and I'm gonna run through all the individual components now it might look a
bit confusing but don't worry I'm going to start right at the start with your starter battery
in most vehicles is starter battery is located under the bonnet and it serves a couple of
purposes when you turn the key it provides the power to start your engine and while the engine
is running it'll run the computer and injectors anything that the engine needs to run and it will
also power the fan radio and all that sort of gear too now to charge this while you're
driving you need an alternator now this is an example of a basic alternator the sort you'd
find on vehicles up until around the mid 2000s its belt driven off the front of the motor and
it's voltage regulated so it will produce around 14 volts or a little bit more into your battery
at all times now in the mid-2000s manufacturers started bringing out this modern technology such
as temperature compensating alternators and smart alternators temperature compensating
alternators are able to read the ambient under bonnet temperature and adjust their charging to
suit smart alternators can take it one step further and as the battery approaches full
charge they'll turn off completely that'll save fuel and reduce emissions but it's not good news
if you're trying to charge a dual battery system with a basic set up in the vehicle because when
the alternator stops charging this battery it'll disconnect the second battery and stop charging
up - stay tuned for part two where I'll show you the latest technology that solves these issues
now that I've gone through the basics of your vehicle's 12-volt system we're gonna go into
dual battery systems why would you want a dual battery setup well it allows you to run your
fridge and accessories at camp without flattening your starter battery here's a simple demonstration
let's say this is your starter battery and you're using it to run your fridge while you're driving
to camp your fridge is drawing power but your alternator is easily keeping the battery charged
up once you rock up at camp and turn your vehicle off your fridge continues running slowly drawing
all the power out of your vehicle until there's not enough to run the fridge and definitely not
enough to start your vehicle that's why you need a second battery it means you can power your fridge
and accessories at camp keeping your starter battery fully charged and ready to go plus starter
batteries are not designed to be charged and discharged slowly instead they're able to provide
the large amount of current that's required to start your vehicle for only a few seconds at a
time that's why you should always use a deep cycle battery to run your accessories at care
the easiest way to add a dual battery system to any vehicle is by adding a completely separate
deep-cycle battery into the vehicle traditionally your second battery is mounted under the bonnet
but these days it's much more common of beneficial to run one in the back of the vehicle there's no
need to try and squeeze a battery into an already crowded engine bay and there's no need to buy an
expensive vehicle specific battery trays if you do want to run a deep cycle battery under the
bonnet you can't use a sealed battery if you do as it heats up the battery acid will vent out
of the battery as a gas and because it's sealed and can't be topped up you'll permanently lose
battery capacity a sealed non gassing battery like this AGM isn't designed for use under the
bonnet but it's perfectly designed and safe to use in your vehicle that's a huge advantage as
it keeps the battery cooler for longer life and it won't reduce the capacity so long as you charge it
properly because it won't get hot enough to vent plus it's closer to your fridge so that'll run
better and when you're keeping your battery is much easier to access and use in general
I always run my deep-cycle battery in a battery box which basically turns it into a portable
power hub it's got all the plugs sockets and terminals that you need to run all your gear
at camp and the benefit of having it completely separate is that you can take it in and out as
you need it and while you're running your gear it won't be discharging your starter battery
that means when you go to leave camp you can start your vehicle easily now what a lot of
people don't realize with a separate battery like this is that it needs to be charged up
batteries shouldn't be discharged all the way to empty which is about ten point five volts
in the case of an AGM for the longest life you should use as little of the battery's capacity
as possible so keep it charged up or charge it up after you use it for AGM batteries discharging to
about 50% of the overall capacity offers a good balance between long battery life and usable
capacity so a 100 amp hour battery has about 15 usable air powers be aware if you're looking at
smaller batteries like a 38 mph em you'll only really have 19 air bears to play with which as
you'll see isn't even enough for a day and night of camping to calculate how much power you will
need you'll need to look at what accessories you've run or a planning to run for example
this 60 liter fridge here draws on average one air power so over 24 hours that's 24 amp hours
total if you're running a few camp lights that draw a combined two amps of current and you're
running them for three hours total that's six amp hours every day together that's 30 amp hours
over a 24 hour period plus you've got to think about any time you charge your phone or add any
other accessories into the system so a little more capacity than you think you'll need is a
good idea if you use this 3088 power battery I mentioned earlier you'd already have used
38 hours in 24 hours with only 8 err powers remaining before it's completely dead flat
that means you've already used about 80% of your battery's capacity doing that will severely reduce
the overall lifetime of the battery if instead you'd opted for a hundred a power battery and
use 30 amp hours you'd only have dropped it down to 70 amp hours meaning you've only is 30% of your
battery's capacity charge it back up at that point and your battery will live a long and healthy life
being over charged and discharged many more times every battery has a limited number of cycles that
it can go through being discharged and charged if you repeatedly drain your battery to nearly empty
you'll get fewer cycles overall compare that to a battery that's only being used a little
before it's being charged up and you can see that you get substantially more out of it have
a look at the difference between a draining of battery to 20% full 50% full and 80% full
a great way to keep your battery charged while you're out for the day or at camp is with a
portable solar kit whether it's a blanket or a folding panel so long as it comes with a regulator
it's safe to keep plugged in and charging all day and it means that your battery will be charged and
your gear will be running properly when shopping for a solar panel check the specs to see how many
amps it can put out there's short-circuit current and current at P max P max is what to look for for
example this 200 watt solar blanket can produce ten point four eight amps at P max if you had a
hundred amp hour battery that was discharged to 50 percent it did still take a minimum of five hours
in ideal conditions where it's charging at ten amps to bring it right back up to full charge and
if you're running a fridge or accessories that are drawing power from the battery at the same
time it'll take longer so rather than waiting for the battery to discharge you should leave
the solar connected as often as possible and so long as the sun is shining it'll keep it topped
up it shouldn't ever drop down to such a low level that it'll take hours to charge back up
when it comes time to leave camp or anytime that you're driving here's another hot tip unplug your
fridge and any accessories and plug it back in to the main 12-volt circuit of the vehicle now
I've added a 12-volt accessory panel with a couple of SIG's sockets that's connected to
my starter battery what that means is that while I'm driving my fridge is running off
the alternator and starter circuit and not off my battery and battery box once you get home
give your battery a really good charge on a 240 volt wall charger or connect your solar panels
back up while it's not powering any accessories so it'll give it a really full charge and take your
battery nice and healthy the next step up from that is if you want to charge the battery in the
back while you're driving your vehicle that's gonna involve running some heavy-duty cables
from the starter battery right back to your deep cycle battery keep an eye out for part two where
I go in-depth into how to charge a deep cycle battery in your vehicle it'll take your setup
to the next level so make sure you hit subscribe and check out the rest of the channel for more
12-volt bush power camping and 4WDing and camp cooking tips tricks and techniques