Dual Battery Setup EVERYONE should fit! EASY DIY 12V Tips

Well today we've got a very exciting video. In fact a lot of you guys have requested this because it's probably one of the most asked about topics that we tend to deal with. It's all about 12 volts. Today we're going to go through everything you need to know about setting your vehicle up when it comes to 12 volt from should I solder, should I crimp, what's the budget set up, I want to go away camping for three days, what sort of stuff do I need in my vehicle, and to make things even better we've called in the big guns, the experts. Now we've gone down to Red Ark. My mate Steve has been an autosparky for over 20 years. In fact Steve is the person when I have a drama I call him up on the phone and say Steve please help me with this. So there's no better person in my opinion to go through some of these questions. So Steve thanks for being available today mate. It's going to be a great video I can just tell. We've got so many questions to go through so I might ask you a few that have come up via social media. So these are all real questions that people have actually asked and I'm going to put you on the spot with a few of them. We'll go through them. By all means. All right. My mates have told me I need a dual battery system but do I really need it? What's a dual battery system consist of and how does it basically operate? I suppose as it says a dual battery system, dual meaning two, we're going to put another battery in. The problem you're going to run into if you just run your accessory loads off of your start battery is you're not going to be able to start your car because you've discharged your start battery. I've been there mate. The fridge is working fantastic for about eight to ten hours and you've got to start your vehicle in the morning. It doesn't work. Correct. And you're thinking oh bugger how do I get out of this situation? Yeah so the best way around that, stick in a second battery and then put in a charger to take care of that battery and also separate that battery from your start battery so you know you're always going to be able to start your vehicle. So in the worst case scenario when you're out camping for the night, say your auxiliary battery goes flat, it's not going to affect your start battery. You'll still be able to start your car in the morning. When they're isolated they're a totally separate system so your start battery is there as if it was always there, never been touched. And then of course when you want to put charge back into that second battery, start your car. Yep, start your car up, charger takes over, puts all the power back into the battery and you're back on track. Yeah right so it really is as simple as battery charger, a second battery but that's the basics of a dual battery system and that'll set you up for what a couple of days worth of camping. Oh yeah a couple of days minimum. You're running you know light loads like that, that's perfect. Yeah and at the end of the day you can go as long as you want off the grid. You just keep having to start your vehicle or use solar I guess to get some charge. 100 percent. The next question is, is the old battery box, the humble battery box, is that worth it for beginners? Yeah, simple as that. Yes it is. Battery boxes are rad. Why is that Steve? They are very simple, it's just a simple plastic box. You've got to put your own battery in right? Yep, that's all you need to do is look at it, it's already done. You go to a shop, get a battery box, it's going to have your Anderson plugs, your accessory sockets, get yourself a BCDC charger, put it on top, wire it in, throw your battery in and away you go. Because the actual battery box is just literally the box with some basic connections in it. You've got to put the battery in. If you want it to charge, you're going to need something like this, a BCDC charger. So you're going to wire this with your battery box and then you've got basically a self-sufficient little 12 volts. This is your dual battery system, all in one little... Just a portable dual battery system for you to use and yeah, take it wherever you want, take it from different place to different place. Now you guys actually make a better version in my opinion of that, which is the GoBlock. Now I'm probably Australia's biggest fan of the GoBlock and I'll say that for a good reason too because I've had one in the back of soot now for a long, long time and it was done as a temporary measure and I've put the GoBlock in the back of soot because it is exactly that. It's got 100 amp hours of lithium, it's got a 50 amp charger, it's got all my Anderson plugs, all the connectors that I need in the back of that vehicle to run a very comprehensive 12 volt system in the back of it and it's portable. Yeah, it is just the next version of portable dual battery systems. It's a really, really good, really handy product. Even just the ability to be able to take it out of sooty and I've used it on the back of buggies to run fridges for the weekend of camping and stuff like that when it's finished, wipe the dust of it, put it back in sooty and we're good to go. Dual battery system plug back in and it's real simple and I think that's for a lot of people who are getting into 12 volt who want a simple portable solution, a basic battery box like this with the BCDC wired up or something a bit more extreme like the GoBlock, which is essentially the same but with a lithium battery and everything put in the one. You don't have to touch anything, you literally need to run power to that and you've got yourself a dual battery system. Next question's all about DIY. What are the four most basic tools you should have in your kit if you want to tackle some of these DIY 12 volt projects? Limit it to four, all right? Limit it to four. A couple more if you want to. So obviously you're going to have to pull things apart in your car, you're going to need a soccer set, spanner set, basic hand tools, but when you come to electrical, side cutters are most important, one of the most important. So side cutters and little side cutters, we'll claim that as one tool. Yep, what else? Crimpers. Crimpers. So these are a version of crimper, they're not ratchet, but they crimp exactly how I want them to crimp. You could abseil off these crimps, they're that good. Really? Yeah, and that's about making a good connection is probably one of the most fundamental parts of 12 volt, right? A good connection. Yeah, bad connection equals resistance, resistance plus current equals heat. You get heat, you get melting, you get problems. Heat means fire, I know this much, I've had this in my engine bay. What's the next one? So wire strippers. Yep. They're nice to have, just make stripping small cables nice and easy, but the really, really important thing is going to be your soldering iron. Yep. So again, it comes down to quality of your tools as much as it does the quality of the product you're installing. Yeah. So if you've got good quality tools, it's going to make your job a lot easier. It does make it a lot easier. I speak from experience, mate, you know, when I'm using decent tools, it's actually, it's a pleasure to work with and it tends to be a lot neater than you're doing your job. Yeah, it does, it does give you a much better result. And what else? Look at the multimeters. Multimeter. So I really, I really like current clamp version multimeters because they tell you a lot more than just voltage because you can actually clamp over the wire and see how much current that the product is actually producing or drawing. It just makes it a big, a big difference and makes it a lot easier to use. And then I saw one more tool on the table, Steve, and that is the old trusty heat gun. Now, I've got to say, I'm guilty. I don't actually have one of these. I've been using lighters and little gas torches for all my heat shrink. But if you want a neat job, you can do it properly. Neat job. So with all these tools, that's pretty much got you sorted for just about any 12 volt. Yeah, you can fit a dual battery system with that. No worries. No worries. Yeah. You can win the ultimate 12 volt setup worth over $10,000. This setup includes one of Redarc's brand new Alpha 50 BCDC chargers. Now these are very clever. They're waterproof, dustproof, and can even charge your How clever is that? It also has a smart battery monitor, 200 air power, HD lithium batteries, a 240 watt solar blanket, as well as one of their brand new 2000 watt RS3 inverters. Now with that sort of setup, it could take you just about anywhere you dare to travel for as long as you want off the grid. The possibilities really are endless and it's super easy to enter. We're going to put a link down below. Simply hit that link, fill out the form, and you're entered. It really is as easy as that. Good luck. Next question, I think it's something that's overlooked by a lot of people, especially people trying to do their own 12 volt system. That's the importance of the earth in the whole 12 volt equation. So how important is your earthing? Your earth's just as important as your power. I know a lot of people don't realize that, right? No, no. Without your earth, the power has nowhere to go. So you're never going to get a full circuit without having a good earth. I know myself personally, when I'm trying to diagnose 12 volt issues, I've always concentrated on the positive side of the circuit and never on the earth. But 90% of the time I'll say it's something to do with the earth. Yeah, it is a very common issue to come across. People fitting things into dual cab ukes and trying to screw into the tub. Oftentimes those tubs are going to be mounted on rubber or something like that, or painted surfaces and the like. So they don't have a good earth connection to the rest of the vehicle. A good way around that is just to build yourself another earth lead, go from the chassis to the tub, and then you'll be assured you're going to have a good earth. Yeah, right. And now this thing here in front of us, mate, a bus bar. Now that looks a little bit technical for a lot of people, but explain the benefits of one of these. Yeah, so a bus bar is essentially just a piece of metal with bolts in it that you can connect multiple connections to. So instead of stacking multiple lug after multiple lug onto one bolt, you can spread them out and get a nice even spread and a neat sort of installation. Because I guess at the end of the day, what you're looking for is good contact. So all your earths have got good contact. If you start putting them just about everywhere, which is what most people do, they find a bit of metal, most of it's got paint or rust or mud over the top of it, it goes on there, earth is done. And like you said before, all the concentration goes on the positive side of the circuit. And that poor old little earth is just, even though it's just as important as the other part, it's just left to its own devices. And then you start over time, especially get a poor connection, that's where you're into big issues. Yeah, correct. And with a bus bar, if you're, you know, if this earth or the main earth going to that bus bar is no good, all the rest of your earths are no good either. Yeah, right. So you have to ensure that the source is sound. Yep. Is it always important to go back to your start battery earth? No, no, no. You just got to make sure that the earth is good. So you can check that with a test light. You can check, just put your clamp on the positive and then poke around, see if you got it. Yep. Not a great amount of load on there, but you can always see if it's working. Do it with a multimeter to check resistance. It's a good thing to consider when doing a 12-volt job yourself. Pay a lot of attention to your earth and make sure most importantly, you've got a strong connection. The next questions relate to cabling and fusing. Basically all the intricate detail stuff when you're doing a 12-volt install. Really important stuff. Very important stuff. So just as a rule of thumb, I know this is so hard to answer, but what size cabling should you use and how do you know what size cabling to use? Yeah, well, we make it quite simple with our instruction manuals, with our charges. So we'll just bring it into BCDC territory, 25-amp charger under the bonnet, both batteries either side of the vehicle, say like an 80 series or whatever. Yep. Eight BNS cables fine for that. When you start to go into the back of the vehicle in a dual cab ute, you're going to want to bump that up next gauge to six BNS. And then as the current of the charger increases, you want to increase the cable size again. Yeah. So as a general rule of thumb though, if you're running like a 25-amp charger, you're going to want to run about cabling that can handle about 40 amps for the length of what you're using it for. Yeah. You never want to under-spec the cable because what's going to happen is you're going to get really hot cables and, you know, risk yourself having a real drama down the track. Yeah, exactly right. Things start to melt. When things tend to melt in a 12-volt application, there's usually big dramas. Lots of other things melt too. It's not much fun. Exactly right. So I guess if you, if it's really confusing, I mean you can go online, there's lots of tables you can use that'll tell you, right, I need to get 40 amps and we've got a distance of seven meters. I'm running at the back of my canopy. What size cable do I use? There are actually tables that'll tell you and much goes with the fusing. You want pretty high fusing, but not super high, right? Yep. You want the fuses to be at a lower rating than the cable. So you want the fuse to blow before the cable melts. Makes good sense too. That's like your sacrificial point of your 12-volt setup, right? And you don't want your load to blow the fuse. Exactly. So it's got to be in that happy medium. Now if you want to take all the guesswork out of that, of course, RedArc do sell actual bundles which has got all the wiring and stuff you need. So everything you need and you can actually specify as far as I understand, if it's going to be in the engine bay, if you're going to have your 12-volt setup in the canopy of a vehicle, then you can get wiring to actually suit. Each kit varies depending on the current rating of your BCDC and then the location of the BCDC. Yeah, that makes it really, really easy. All right, now let's talk about the details. If you're going to be doing this yourself, you're going to do some 12-volt jobs. Should we be crimping or should we be soldering? Well, depends on your cable size, obviously. So anything nice and small, solder away. I always like to crimp, especially with larger cables for inverters and things like that, because you're never going to be able to solder that properly with the amount of heat needed without damaging all the insulation and things like that. Avoid blow torches and things like that, it's not a great sort of idea. You're better off getting a really good crimper and just being able to crimp the crimp the lugs on to the cable. And I've also heard as well, and this probably goes in the same territory of like bigger cabling, if you put a lot of solder in, you're going to make quite a brittle connection. Yeah, you can make it a weaker point for the cable may snap. Okay, so say you want to crimp something like this. Now, nine times out of ten, a lot of people would be using a pair of side cutters and they would be just having a crack to try and get that nice and tight, right? Yeah. What's the correct way to do it? I probably wouldn't do that. I really like these big guys here, nice open, good lever point on. Can go in a vice and you can just crimp down nice and hard. So you're welcome to crimp that bad boy if you want. Even a bloke like me can do something like this. So spinning around, I just like to crimp the bottom so that sits in there. Yep. And then just give it a good old push. Okay, use your strong hand. You might have to zip it out a bit. It's really quite hard. I'll have to have it zipped out. There you go. So you can pull him out again. This is the sort of connection we're dealing with here. As you can see, we call this the pull test. How's it going? What you want to do is grab your lug and actually give it a good pull like that and make sure it's not losing as you get. This is not moving at all. So that's actually crimped in really well. What if you've got something smaller? Something smaller? Say you're just using normal wires that you might use for some sort of light load or something like that. I like to use these guys here. Stick them in the back, crimp one way, spin around, crimp again. Just like that. You won't be able to pull that one off either. Yeah, right. Yeah, there you go. So many times I've seen these incorrectly crimped and there's just that little bit of movement. As soon as you get any movement whatsoever in that connection, start again. It's movement means heat, heat means problems. Yep. And then you've got your Anders as well. So these are good for Anderson plugs. A lot of people would heat this up and pour solder into it. If you do it right, it's fine. But if you just heat up that and then jam your cold cable into it, you're not going to get any flow into the cable. So you're going to have a poor connection again. Right, right. So you can have a molten pool of solder, cold cable just pushes out and doesn't really do much to the cable. Yeah, fair enough. I'm sure there'll be plenty of people that say it's perfectly fine, but. Yeah, no, but look, but this is a, I mean, if you're, we're talking about people who don't know better. We're talking about people giving it a go themselves, trying to save a few dollars to do a DIY job. If you can teach people just the basics of doing decent connections, and if that's just getting a set of crimpers and just manhandling the thing, it's nice and easy. You're going to get a connection and you're not going to have any dramas down the track. Yeah. I mean, you can solder them quite, quite well, but I'd probably recommend to install the cable and then solder and push the solder in while it's all heating up at once. Yep. So yeah, at the end of the day, this is the way I do it. It's the way I've been doing it for a long, long time. I don't have any dramas with my installations and the tools that I'm using aren't overly expensive either. Yeah, anyone can do that, but it's a good thing to do. I mean, like, you get back down to the basics, we've harped on about it, but having a good connection is just the, it's the cornerstone to any good DIY 12-volt project. You get good connections. Yeah. It's going to last a lot longer. Because it's not, it's not this part of the cable that's going to let you down. Yeah. It's the parts you've mucked around with. Yeah, exactly right. I know that all too well. Steve, you also got another question about fuses, and it's about fusing the earth. Is that necessary? No, not really. I haven't heard about it too many times. No. In DC, you know, vehicle electrics, generally you're positive where your fuse will be, and then that runs through to your load, through to your ground. Most short circuits are always going to occur between a positive cable and the chassis or the ground of the vehicle anyway. Yeah. So you've protected the circuit on the positive. The rest of it's fine. Right, Steve, you've gone to the effort of putting in a whiz-bang 12-volt setup in the back of your four-wheel drive. Now you want to run your accessories. What's the best way to wire up your accessories? Well, during your planning stage, you would think about, how am I going to connect all my accessories? Do I need a fuse box? Yes, you do need a fuse box, or you need some way of protecting it. You could, you know, just have them strewn about the vehicle willy-nilly everywhere, but it's not very neat. I do, and that's where you, I think you've got to look at the other side as well, is when you want to diagnose something later on down the track, how easy is it going to be to do that? Yeah, that's right. So if you haven't done beautiful crimps and you've got issues somewhere, if you've wired the system nicely and you've got a good central hub for where everything goes to, you'll make it easier on yourself to diagnose that, as you said. Yeah, exactly right. And I want to grab this for two seconds, the TVS Rogue, because this will cut a lot of the guesswork, I guess, out of it. So you want to run your accessories. This is a really handy bit of kit. Yeah, the Rogue's great. 10 amp channels on it, run your fridge, run lights, plenty of stuff. Party lights, mood lights, all the stuff you might need in the back of your four-wheel drive. Yeah, revolving bed. These things are awesome, they have everything. If you want to run something that's at a much higher level, say a dual compressor or something, you can use one of the channels to trigger a large relay that will then feed from the battery. So super versatile. If there is any issues with the system, you'll generally get a warning on the screen and things like that, so you know which circuits to tackle. Yeah, and diagnosing it, it's as easy as that as well, because you can log in with your phone via Bluetooth and actually see what's letting you down or what's going wrong. If you do want to add to it, so say you've planned your system, you've done it all properly, at the moment you've only got a fridge and camp lights and you know down the track, though, you want a compressor, you're going to want to put maybe some other lights in or some other 12-volt bits and pieces, can you add to it? Yeah, well, it's simple. If you haven't used all the channels and you want to add more circuits to it, that's not a drama at all. The cables are all there, you just need to connect to them, jump in your configurator and add those via the app. Yeah. So a very, very seamless sort of way to add new things. And what about fusing? So all the fusing in this is digital, essentially, so there's no physical fuses on this system apart from the main input fuse, which is going to be a 50-amp MIDI fuse. Yep. You'll never have to worry about that, but this actually monitors the circuits and looks at temperature and current for each circuit, and if there's anything wrong, it'll let you know about it. So even if you do mount this into sort of a tricky spot, which takes a little bit of getting to, if you do a fuse, you're not going to need to worry about getting in there to replace it a fuse like you would otherwise. No, it'll just tell you you've got a problem with this circuit, you can track the fault, fix the fault and it'll reset itself. Steve, let's talk about the topic of safety. Obviously, when you go to do a 12-volt job yourself, now, if you get it wrong, yes, it's not going to work, but more so when you're doing working with 12-volt, you could actually cause a fire and danger, you burn your whole vehicle to the ground. So it's important to get these things right. What are some key steps that people can take to prevent safety issues? Yeah, no worries. So obviously, we've already discussed cable size, things like that. Yep. Undersized cable is going to be a drama. Fusing. Fusing is the main thing that I often see neglected or missed out on. We need to make sure that when we're installing a circuit, we're using the correct type of fuse, the correct size fuse. And not only that, that it's really close to the power source. So we want as little unfused cable between the fuse and the power as we can. I think a lot of people get that wrong, right? So if you're running a cable from your start battery, say, to inside your canopy, where does your fuse go? Right at the start battery. Correct. Right there, rather than right at the back of the vehicle. Because otherwise, you've got all that cable that's unfused. Yeah. Makes good sense. And there's so many different types of fuses on the market. You've got blade fuses, you've got mini fuses. What do you guys recommend? It depends on what you're doing. So blade fuses are great. They're nice and easy. You can buy, you know, you can get really good blade fuse boxes and things like that. And they're great for accessories and the like. Fridges. Fridges, lights, all that sort of stuff. But when it comes to high constant current devices, such as BCDCs and managers, and even inverters, you want to use a fuse, a mini fuse, or even a mega fuse. So inverters, obviously, that's, you don't want to be mucking around with that. And that's where you see a lot of your problems, particularly with your BCDC installs. If people aren't using a mini fuse and they haven't done good crimps and tight connections, that's where they'll find a failure point. Because you get the heat and then the lack of connection. And then they go, what's wrong with my system? Yeah. The BCDC has melted my fuse. It's like, no, that's the bad connection. It's a bad connection. It always comes down to bad connections, I typically find. So just explain, for instance, if I was to get, say, a 60 amp midi fuse and I could find a 60 amp blade fuse, why would we go a midi fuse over a big blade fuse? Again, that's down to the connection. Because I can bolt down my terminals, crimp my lugs on, I can bolt my terminals down, the nylock nuts on there, they're not going anywhere. It's not going anywhere. You put the fuse in the big blade fuse, put it in once, probably going to do you well for a long time. You ever have to pull it out and put it back in, you're probably going to end up with dramas down the side. Trance moving around that causes heat, they're going to start to melt. You always find a blade fuse that's melted that usually lets you down. You're like, why is that melted? It's the connection. Correct, yeah. Okay, now obviously when we're running wires in a four-wheel drive, you need to consider where these wires are going. Because a four-wheel drive is not just staying on the road, typically it's going to be going through water, dust, corrugation, you're bouncing up and down. Yeah. And what's some key considerations there? Yeah, so generally if you've got other cables you can run with, you know, they're probably put in by the manufacturer, it's going to be good. Not going to get in the way of any pinch points and things like that, you know. Seats moving and all that sort of stuff is also something people should consider. Suspension going up and down. Yeah, suspension, moving parts, because yeah, it might sit there and look nice on the ground, but then you turn the wheels and you start rubbing, it's a drama. Big problems. Going through firewalls, always using grommets and things and not just running direct against metal without either conduit or a rubber grommet through there. Here's another question and I think this is quite a common one as well. Why do I keep ruining my AGM batteries? Yeah, it's pretty, it is, like I say, it is a common question and it's a common answer. What's happening is we're probably just discharging the battery far beyond what we're meant to be doing to keep it healthy. That's an important point, Steve. So how far can you actually discharge one of these AGM batteries before you start doing damage? Well, with an AGM, generally it's around 50%. You don't want to go below the 50% mark and if you do, that's when you're starting to cause different issues with inside the battery that over time become unrecoverable, so you end up having to bin your battery. Yeah, right. So for the ease of simple maths, let's call this 100 amp hours. So you're saying when we get below 50%, i.e. 50 amps, you're starting to damage the battery. Sure, you can go a bit lower than that if you want, but every time you do, you're going to reduce the amount of times you're going to be able to charge it back up and bring it back to full. Steve, an analogy I like to use trying to keep your battery in good health is imagine trying to step up onto a little baby step. You can do that a million times. That's like your battery discharging, right? So it can handle those little steps all the time where you're only taking a little bit of power out of that battery. Then you try and step up to something bigger, like stepping up to a fridge or something like that. Your legs are working harder. You're going to tire yourself out more and do more damage to yourself by trying to do that. And at the same time, if you're trying to climb on top of the roof of your vehicle or something crazy like that, you're only going to do that a couple of times before you can't do it anymore whatsoever. Yeah, well, that's a very good analogy. It's exactly what happens with these batteries. So that's AGM batteries taken care of. Now we go into lithiums. Now, lithiums, as I understand, can handle a lot more discharge before you start to hurt the battery. Yeah, they can. So they can go down way further. So we've got 150 amp hours of usable power in that one. Yep. So there's 100. We've got 50 amp hours usable power. Yep. So that's 150, but we can use all of the 150 in this one. Correct. Yep. Not all lithium batteries are the same, right? There's all different types on the market. You've got cheap ones, really cheap ones, in fact, to really expensive ones. What's the difference? What are you buying in your lithium batteries that differentiate the cheap ones to the expensive ones? Well, the difference really comes down to quality of the cells, the construction of the cells, and also the circuit board or the BMS inside the battery. When we're dealing with high quality batteries, the cells are all matched and balanced, and also the BMS is matched to the cells. So if the cells are rated at a certain current, they can do 50 amps continuous. The BMS won't allow the battery to provide any more power out than 50 amps. So your cells are doing exactly what they're supposed to do. That's a lot safer then, I suppose, as well. Safer. So you're not stressing the cells, whereas the cheaper lithium batteries, you'll find you can put a BMS that would let it do 200 amps, but it's only supposed to do 50 amp cells. Right. And they'll be stressing that battery out. So it can be working overtime and potentially lithium could be volatile. It's just going to cause the life of the battery just to be diminished incredibly. If you want to take it a step further and be able to monitor what your battery's doing, you can always add the little smart battery monitor to the portable box. And again, you've got a pretty good system. You've got a great little system that's all compact and quite portable as well. So what this will actually allow you to do is you can log in with your phone via Bluetooth. You actually see the state of charge to making sure that this is actually charging and doing what it should do. Yeah. So you can see your battery level and also how much current's going in, how much current's coming out. Coming out. It's a good little addition, actually. That's a great little thing. So you run that with a BCDC charger and the battery of choice. You've got a pretty cool little setup. You've got a very good setup. Yeah. It's more than enough for many people. I think one of the benefits as well of having either the GoBlock, which is 100% no install basically, is your install's very minimal. I think for a lot of people, buying the components is one thing, but actually installing it, a full 12-volt setup in your vehicle is a huge part of the puzzle. Yeah, it is, isn't it? You can take the guesswork out. Yeah. And it can be a big deal. Lots of people may not have their car. They might swap cars quite frequently or they have a leased car or something like that that they can't modify. So it's a really good option. David, our next question relates to solar and it's a pretty open-ended question. How much solar do I need? Now, so many people will have that question because they're typically trying to run something like a fridge or a basic setup. How much solar is going to keep on top of my needs? Yeah. Well, with solar, there's so many variables, so it makes it a bit difficult, but generally give yourself a bit of a rule of thumb of six, seven hours of sun a day on a good day. And then that's when you start to look at your wattages and your currents and how much power you can actually get out of a solar panel. Right, right. So if the basic 12-volt setup, they're running a fridge, they're running some camp lights, what would you say is a good size solar panel for them to run on their vehicle, either fixed mounted or portable? We'll go into the differences later. Yeah, but just as in terms of how much watts of solar should someone be running on their roof? Yeah, so I'll run on, just do an example of what I run. I'll run a 150-watt solar panel on the canopy of the Harlux and my fridge never turns off ever. Yeah, right. I haven't turned it off since I've owned it. Yeah, and I'm in a much similar situation. I think I have 300 on top of my 200 series, but I've been running two fridges in that on big trips for multiple days. And again, the vehicle hasn't turned on, yet my fridges are still cold. Yeah, exactly. So it depends on how much you want to use, but if you've got one fridge, 150-watt solar panel, it seems to do the trick. Yeah, one fridge and some lights, you'll be fine with the 150. You'll even get away with the 120, just running a fridge and some lights. Yeah, obviously you'll discharge your power overnight, but come the morning when the sun pops out, you're going to get some really good sun, especially in the middle of the day. That'll get that battery back up to speed. You'll be able to use it all again the next night and go through the same cycle. Yeah, no, it's a good thing. I can't recommend solar enough to any setup, whether it be fixed or a blanket like this one, but I love the fact that a fixed one, set and forget, and you don't have to remember to put your solar out or something like that. It's just when your vehicle's turned off, solar's coming in. Good to go. Let's talk about different types of solar panels now. We've got a couple in front of us now. We've got fixed mounted solar panels, and of course, a folding or portable one. Yeah, the differences are, I suppose your fixed panel that's flat on the roof of your vehicle or your caravan, so that gets direct sun, you know, midday and varies either side. Blankets and folding panels are great because you can actually maximise what you can get into them by directing follow the sun, so it's basically a solar tracker that you can control. Exactly. I tend to travel with a lot of these in my vehicle, especially if I don't have one of these hard mounted to the roof, and I find that I can park the vehicle in the shade, yet run a lead out with one of these, and like you said, follow the sun so I can maximise the amount of charge I'm getting back into the system. And there is specs, obviously, on a panel, so every solar panel will have a little window or a label on it telling you the specifications of it. So this is a 160 watt solar panel, tells me that my maximum power voltage is 18 volts. Okay. And so I can divide 160 by 18, and that's going to tell me what my maximum power current is, and that's 8.9 amps. You're right, so on good conditions, you're going to get nearly 9 amps into your battery, which is heaps. Yep, use an MPPT solar, you might even get a shade more. Yeah, wow. What are the pros and cons of under bonnet, in cab, or in your canopy for running a charger? Well I guess it comes down to what you can actually do, so I guess under the bonnet you're limited to the battery type you can use, and again that'll come down to battery size as well, so your space is quite limited. I suppose you've got a lot of water, dust, ingress inside the bonnet, so you need something that's waterproof. Yeah, you need something very rugged like a ECDC Classic or an Alpha to make sure it can handle all the sort of harsh conditions, particularly, you know, going through mud puddles and deep crossings and things like that. You want to make sure that the charger can handle what you're throwing at it. Yep. Same as the Weekender kit comes with the Classic and the bracket to actually mount it under the bonnet. Yep, now what about in cab? In cab, so you could run a lithium battery if you like, so you're better off running a lithium battery in there without, you know, venting gases inside your cabin and things like that, because you don't want to be sitting in the car driving while it's charging and gases be venting into your area. So yeah, lithium's for sure, and we can use a BCDC core for that. Yep, which is basically very similar to a Classic. Well it's exactly the same, it just has had the ruggedization taken out of it, so it has to be inside the vehicle, but the performance is exactly the same. Yep, yep, and a lot more affordable as well. Yeah, it's a really good option for people that are using them for in-cabin or in canopy even. If they're out of the weather, they're perfect. You save a good amount of money and, you know, it might be the way for you to get yourself a BCDC charger. Yeah, right. Now what about in canopy? I suppose your options start to open up, but you've got a little more space in the back of a canopy on the back of a ute, say. What's your best sort of solution there? Yeah, well you've got a lot more space in a canopy in general than you do under the bonnet or in the vehicle, so you can run BCDCs, managers, more batteries, more power, more accessories, inverters, all that sort of stuff, so you're sort of opened up to a lot more choice and a lot more flexibility. There's an option for every single situation, it just depends on what you're chasing. Here's a good question, Steve, how do you choose the right size charger for your application? Is bigger just better? No, not always, so it's really important that you look at the specifications of your battery. So as we say again, planning, step one, put everything out, step two, choose your battery as well, and then decide if it can handle what you want it to do. Right. So this guy here has the information on top, there you can see there it's got recommended charge current between 12 and 30 amps. So that's basic AGM battery, that's pretty standard really, up to a maximum of 30 amps, so you wouldn't want to get a 100 amp charger, in fact you couldn't use a 100 amp charger. You could, you would just end up with a big fat round battery. Yeah, that'd be your day job. So a 25 amp charger is ideal for this in the canopy or wherever. Yeah, and if you had, say, you wanted to run two AGM batteries, right, do we double that? Yeah, so you can double it up, so if you put two in parallel, you can double it, you put three in parallel, you can triple it, it just stacks on top of each other. So if you're running two of those, the maximum you could probably go for is, say, a 40 amp charger. You could get away with a 50, so yeah. Okay, but now with lithiums, the whole different dynamics with these sort of batteries, what are your options? Again, you still have to pay attention to the specifications, so we've got a variety of different batteries, from the low draw lithiums, to the high draws, to the to the alphas here, and this alpha can actually charge at a constant 135 amps. Yeah, right, so basically the sky is the limit when it comes to that one. You could run an alpha 100 amp, but you can also, if you wanted a slower charge, you could get away with something a lot smaller. Yeah, you don't have to go to its maximum, obviously. If you do plenty of driving on the road, or you parked up a lot, you've got plenty of solar, you can mix and match. Right, I want the biggest and the best of everything. I'm going to go 100 amps, I'm going to go an alpha lithium, and I want to be able to charge at a full 100 amps. Is there anything else you need to consider? Well, it's going to be cable size, and also your vehicle alternator. I think a lot of people wouldn't even consider their vehicle alternator. General rule of thumb, I'll stick to no more than 50% of the total alternator capacity, to give yourself enough of the vehicle to handle itself, and then for you to use to charge your battery. So you definitely need to pay attention to what your alternator is doing. I know some of the vehicles have very, very small alternators. They do, they do, but you can actually, there are alternator upgrades as well. If you're hell-bent on running a really big system, because you might need it, because some of the appliances you want to run are quite large, you can get away with it, but you need to consider your alternator size. Yeah, and again, we've thought about that, that we might be camping up, and we want to plug in to 240 and get 100 amps, but on the vehicle input, we only want to run 60 amps. Like, we can adjust the input current of the manager, and also the BCDC alpha to suit. Yeah, that's pretty clever. Well, Steve, thanks for that, mate. That was absolutely epic. We've gone through just about everything there is to know about 12-volt systems in the back of your vehicle, but more importantly, how to choose the right products so you can get the exact setup you need. You don't waste a single dollar in the process, mate. So, thank you for that. Now, obviously, you guys might have some questions, some things we might not have covered. Make sure you put them in the comments below, and I reckon that's enough for us, mate, and we'll see you next time on 4WD 24-7.