Best Caravan Battery Setup; how to pick the right one
When it comes to Caravan and camping, you can spend a lot of money on gear that you don’t really need. In this post, we take a look at the Best Caravan Battery Setup for you, what you need to purchase and everything you should consider before laying your hard earned money down.
The first, and most important point to make is that that everyone has different needs and wants, and that means that the best caravan battery setup for me is likely going to be different to that of you, and your neighbour.
To make it simple, we’ll cover a few critical things, and then go into various stages of battery setups, and you can pick something that suits your travel style. The most important thing though, is that what you buy does what you need it to.
Power consumption needs vary wildly
Caravan owners use a wildly different amount of power, and that translates to very different battery systems needed. Some older caravans didn’t even come with batteries, and the only way to run the lights and accessories was to plug the van into a 240V power point at the caravan park that you arrived at.
On the flip side, there are those who want to be able to run their air conditioners for several hours a day without being at a caravan park, and that uses an extreme amount of power, and requires a big system.
Caravan parks or no caravan parks
How you travel will hugely impact the battery setup you purchase. If you hop from caravan park to caravan park and regularly plug into 240V, then your options are increased hugely as you can charge your batteries up from the mains power very easily, and run any big appliances off the powered sites.
Big battery setups can be extremely expensive
You can install a very basic battery system in a caravan for a few hundred dollars, if it does what you need it to. On the flip side, if you want a big lithium battery setup with solar chargers, DCDC chargers and an inverter you can be looking at anywhere from 1k to 25k. Yes, we’ll go into the different options below, but know that you can blow a lot of money on caravan battery systems!
You often can’t run everything off grid
If you are like us, and prefer to camp away from the caravan parks and crowds, you won’t be able to plug into a 240V power point very often. This means that your caravan battery system has to run everything, and whilst batteries have come a long way, there are still limitations.
At home you can comfortably flick your aircon on, along with the oven and even boil the kettle for a cup of tea. Unless you have a medium to high end system you won’t be able to run even one of those appliances full stop. If you are able to run one, it won’t be long until your batteries are flat, unless you have a lot of capacity and solar.
On that note, this post dives into it more – How to run 240V appliances when you are camping.
Charging the batteries is just as important
Storing the power that you need to consume later is the first step of the puzzle, but you need a way of charging the batteries back up again. In general, this is done in 4 ways; using the power from your vehicles alternator, using solar panels on your roof, charging from a generator or plugging into a 240V socket at a caravan park/private property.
What do you actually need in a Caravan Battery System?
Obviously, you need a battery, or a number of batteries in your caravan. These can be the traditional lead acid deep cycle batteries, or a lot of people are moving to lithium batteries. They will almost always be 12V in a caravan, and need to suit the appliances you want to run, and the duration you need to run them for between charges.
Here’s a good starting point – How long will a 100aH battery last?
Cable, fuses, lugs and other accessories
In general the cable in a Caravan is already completed, but if you are doing a big upgrade you can find that it is not large enough to cope with the extra demand, and you need to replace it with something heavier duty. You can look at voltage drop calculators, and various cable manufacturer charts that specify the correct cable size for its duty.
This is where a good auto electrician comes in, as they can size everything to suit your setup, and you won’t end up with weak points, and potentially dangerous safety issues as a result.
Solar panels and charger
Most caravans today come with solar panels on the roof, and a suitable charger. You cannot charge your caravan batteries with a solar panel that does not go through a solar charger (or regulator as many people call them).
Again, the charger needs to suit the number of panels, and if you upgrade to more (or larger) panels then often you need to replace the charger.
Sizing your solar panel array is also very important, with the recommended size being somewhere between 1.5 – 2 times the amp hours of battery that you have. If you have 200 amp hours of batteries, you really want 300 – 400W of solar available. Yes, this is negotiable, and it depends on how you travel, but be sure to think about charge times, available sunlight and so on. 1.5 to 2 times is a good guide.
Other charging methods
Relying on solar only to charge your caravan batteries is a mistake. There will be days when you are parked in the shade, or its overcast and there’s very little sun. The most common way to charge caravan batteries asides from solar is to use your vehicles alternator, which is done by having a cable run to the rear of your vehicle on an Anderson plug, and your caravan plugs into this.
Some are wired directly to the caravan batteries which can work depending on the voltage drop and battery type, but most today go through a DCDC charger, which is mounted close to the caravan batteries and does a much better job of charging them in this situation. For more information, check out What is a DCDC, and do you need one?
Alternatively, some people use an AC to DC charger, which takes mains power from a generator, or from a power point and charges their 12V batteries.
Most caravans today come with a 12V system that does your lights, water pumps, fans and other bits and pieces. Many will come with a 240V system as well which will do your water heater, aircon and so forth. You cannot run any 240V appliances off a 12V system without having an inverter.
This takes 12V power and converts it to 240V. Sizing your inverter is hugely important, to ensure that you can run the appliances you need. Obviously, buying a big inverter and hooking it to a small battery system with limited panels is not going to work either; batteries have maximum discharge rates, and you will damage them by drawing too much current, too fast.
You might need an inverter, and you might decide it isn’t worth it. A lot of people do not have them, and just use 12V chargers. It isn’t a must, but it is important if you want to run 240V appliances.
Different Caravan Battery Setup Stages
For the purposes of making this simple, I’ve created 6 stages of battery systems that people typically have, ranging from your basic setup that runs very little right through to a stage 6, that runs a compressor fridge and heavier 240V appliances. You should fit somewhere within these 6 stages, and be able to get a good idea of what you actually need.
Stage 1 Caravan Battery System (basic)
The first, and most basic caravan battery system is a single lead acid deep cycle battery, a single solar panel on the roof that charges through a basic solar regulator. These style caravans will always have a three way fridge, which runs off gas for majority of the time except when you are in a powered camp site, or driving.
Most of the time these don’t have a DCDC charger, and just take power directly from the Anderson plug of your tow vehicle to charge the batteries, and run the fridge (which doesn’t work too well if your vehicle has a smart alternator).
If you are a light battery user, or you spend majority of your time at caravan parks then this setup works just fine. I have good friends who are travelling Australia in a caravan with their two kids using only a single 100 amp hour AGM battery, an 80 watt solar panel on the roof and a small folding solar panel, and they regularly free camp and stay away from power points.
You’ll still be able to charge your phones and other devices, but you need 12V chargers and you have to be careful that you don’t flatten your battery too much.
Stage 2 Caravan Battery System (basic plus)
The next stage is to add a bit more solar, and batteries. Our Reconn R2 probably fit this this bill (prior to upgrading recently), with two 120 amp hour lead acid batteries, and two 120 watt solar panels on the roof (although one did come off – Check your caravan solar panels!).
This allows you to run most 12V appliances including a compressor fridge, but only a small unit. We did manage to get away with running an 82L Evakool fridge freezer as a freezer, but if it didn’t get a solid charge in every day we were in trouble with power.
Stage 3 Caravan Battery System (light 240V appliances)
The next stage is similar to stage two, except we introduce the use of a small inverter. Something around the 150 – 400w inverter suits running light weight 240V appliances like 18V battery chargers for portable tools, camera battery chargers, laptop chargers and other bits and bobs that you have which are not able to run, or charge on 12V.
We have often run a normal, full size 240V fan when its really hot, as they draw very little power and move a lot of air.
Stage 4 Caravan Battery System (Upright compressor fridge and light 240V appliances)
The next stage involves ditching your 3 way fridge, and installing a fully electric fridge. This can be done one of two ways; a 12V compressor fridge, or a 240V one operating through an inverter. Both methods are actually very feasible, but will result in the need for more battery storage and solar.
Again, you’ll be able to run light 240V appliances off a small inverter as needed.
Ideally, you have about 150-200 amp hours of usable capacity, and 400W of solar on the roof. This is where people tend to go down the lithium battery path, as carrying 300 – 400 amp hours of lead acid battery is starting to get seriously heavy (and only using them to a 50% depletion rate).
Most people generally have a DCDC by this stage, to ensure they are charging the van well when driving along too.
Stage 5 Caravan Battery System (Compressor fridge and heavier 240V appliances occasionally)
If you want to be able to run a coffee machine, or a microwave, or a kettle a couple of times a day, along with your compressor fridge and the usual low power draw items in the above stages, you need more batteries, and more solar.
Anywhere from 200 – 300 amp hours of usable capacity and 400 – 600W of solar will do you just fine, but it needs to be lithium batteries to accommodate the high current draw. Lead acid batteries are simply not able to provide high currents without doing damage (or having many linked up).
On top of this, you need a suitable charger and cabling for the panels and discharge side, and ideally a way of charging from your vehicles alternator (DCDC charger).
You’ll also need a suitable inverter, which will depend on the exact appliances you plan on running. Something between 1500 and 3000W will suffice.
This system will get away with running an aircon for an hour or two here and there, but nothing more.
Stage 6 Caravan Battery System (Compressor fridge and heavier 240V appliances often)
The last stage is where a lot of money is spent, and allows you to run basically what you would at home, but off grid.
Here, we are talking 1000 – 1500 watts of solar on the roof, 400 – 600 amp hours of lithium batteries and a big inverter to boot.
If you want to run your aircon overnight, or ditch gas completely (electric or diesel hot water and induction cooking) then you have to fork out big money to get a system that will do it electrically. Yes, its possible, if your pockets are deep enough, and you have the weight capacity.
Please note that even in this stage, you can run out of power if you get a few cloudy days, or you are a heavy user. Entirely relying on solar is a mistake, and you need to be sensible with your power use (and swap to gas cooking as needed!).
Where are we at now?
A couple of months ago I finally bit the bullet, and purchased a heap of Renogy gear. We grabbed two 170aH Renogy lithium batteries, a 60 amp solar controller, Bluetooth monitor, 3000W inverter, three 200W panels and had it all installed by our mobile auto electrician (I did the mechanical side of it).
Essentially, we now have 340aH of lithium, and 720W of solar on the roof, and a portable blanket that we can throw out if we really need it.
This gives us 3 days of run time with just our 82L freezer, lights and water pump without any solar going in. If we use the induction cooktop, we are down to about 1.5 days of use, so we only use it when the weather is favourable. For us, this is enough and we won’t be going any bigger.
Caravan battery brands and what to look for
I’m not going to give you specific advice on different caravan battery brands. There’s hundreds out there, and they range in price and quality. I’m not convinced you need to spend mega money to get the best, but don’t buy the bottom of the barrel either.
For lithium, you have VoltX, Kings, Atlas, Solar king, Itech, Renogy, Invicta, Revolution, DCS, Redarc, Enerdrive, All Spark and the list goes on.
Look at the cell type, warranty provided, maximum discharge rate, maximum charge rate, cost per amp hour and so on and so forth, and then make an educated decision.
How much do you need to spend?
Everyone would love to be able to run their aircon, and 240V kettle and other household appliances when off grid, but it costs a small fortune to do this. Matching your budget to what you want to run is important, so you have some buffer room for bad solar days, and you don’t blow more money than you need to.
There is an argument that if you have a significant system you can comfortably stay off grid and avoid expensive caravan parks, but you need to find out where you sit on the scale.
What’s the best caravan battery setup?
Put simply, the best battery setup for a caravan is the one that does what you need it to. A lot of people still use 3 way fridges, and have no need for any electrical devices off grid that draw much power, and you’ll get away with a system that is between 1 and 3.
As soon as you move to a compressor fridge, you need more capacity, and more solar.
There’s a heap of options out there, and you can often upgrade fairly easily. Adding another battery to the existing setup should be very quick and easy to do, providing you can find somewhere suitable to mount it.
It’s really important that you get something a bit larger than what you actually need. There will be days with very poor solar generation, and if you have a system that is built with limited leeway, you will spend your time watching the battery levels, and running your vehicle to charge the caravan instead of kicking back and relaxing, like you could be.
What caravan battery setup do you have? Are you happy with it? Have we missed anything in this article?