Building a 12V Battery & Solar System: Do's and Don'ts and All the Basics You Need to Know

hey guys in this video I thought we would take a nice little walk through of the basic pieces and parts and general configuration uh considerations that you might want to have under your belt before you tackle a kind of a little basic DIY system here with an inverter battery and solar charging if you're not familiar with that I thought maybe this might be some uh kind of introductory content that you would find helpful now I know this looks like a this looks like a promo for B RV I swear it's not they actually don't know that I'm doing this video I I did a a review another time on this inverter I already happen to have it on the wall they did send me this uh fairly new charge controller that they came out with this is the the the sunflow 30 amp um and uh you know I'll put links to this in the description below if you're interested but this is not about the the B RV product specifically I just happened to have it handy and I thought you know I actually have enough components from B RV at this point that I could build a complete system including solar panels outside which we'll look at in a minute I'm kind of just kind of talking about this bit right here and this is a basic uh 12vt 2000 watt setup and I happen to be using two 100 amp hour batteries now these again these happen to be bjar V batteries and these are self-heating which is nice if you're not familiar with this kind of Battery Technology um lithium iron phosphate which is mostly what I talk about on this channel in terms of battery chemistry definitely the way to go because they are the longest service life batteries out there um this particular one has self-heating and low temp protection which is nice if you happen to be an environment that is going to be subjected to multiple days of subzero or subfreezing weather we'll say um and these have the ability to kind of heat themselves so that they can keep being charged and discharged in extreme cold weather um because they have self-heating built in now if you see a battery that is just low temperature protection it's not going to have a heating element built in you could add a heating element on the outside if you wanted to but low temp protection basically just means if if the uh ambient temperature or the battery temperature specifically sensors are reading a below usually about 32 Dees Fen or 0 celsus uh freezing temps they will shut off the ability to charge the battery it will give you a little bit more leeway for discharge uh but not charging because you might damage the cells if you do that unless you have a self heating mechanism built in so you obviously pay more for low temp a little bit more for low temp charging than batteries that don't and you pay a little more on top of that for batteries that have self-heating capabilities now these are both 12vt uh 100 amp hour batteries you could do this system with a single battery I've got these connected in parallel which means I am adding up their current which means the total capacity of this uh two battery system in parallel is 200 amp hours but it is still a 12.8v system so I'm basically doubling my capacity this way by connecting the negative to the negative and the positive to the positive so 200 a hour battery but still a 12vt system which is necessary because this is a 12vt inverter and your batter's output voltage basically needs to be compatible with your AC inverter up here I have a charge controller this allows me to get power from the charge uh from the solar panels and regulate the power from the solar panels which fluctuates pretty wildly and it regulates it in a way that is safe to charge the batteries and this particular one this sunflow 30 amp from B RV does support uh 12 amp four uh 24volt configurations uh they make another version that I did a a review on a year or so ago that also supports 1224 and 48 volt conversions uh or system uh configurations and is also a 40 amp uh output now when you see 30 amp that does not mean 30 amps in that is the amperage that it can charge the batteries at the the rate of charge so you need to make sure that the charge controller is an appropriate size or has an appropriate output or charge rate for the batteries that you're going to be charging so uh this is actually a quite a good matchup for a couple of 12vt batteries to have a 30 amp charger now what's going on here this is a bus bar uh configuration and I've got it rated these bus bars are rated for 250 amps which is appropriate for this system because each one of these batteries can sustain 100 amp output now this um this 2,000 watt inverter uh is not going to pull uh 200 amps uh for very long uh because that would be um that would it's going to trip the overload uh protection or overcurrent protection on on the inverter if I do that but the batteries are capable of it and so I wanted to make sure that the bus bars could handle that kind of current but what bus bars allow you to do is they allow you to land your cable connections on their own terminal and so we have a shared negative and a shared positive bus bar and that makes it much easier and it also creates less resistance because whenever you're stacking uh these ring terminal connectors um there is there is more resistance created and more heat and you do get a little bit of voltage loss when you do that this just makes it a little bit easier for cable management and also reduces the the resistance in the system when you're trying to stack uh multiple terminals on top of each other so in fact in the previous video that I did on a 12vt uh DIY build like this I um stacked the charge controller and the battery terminals up here up on up on the AC inverter and a lot of people were kind of freaked out about that you can definitely do that it's not optimal uh I just wanted to show you the quick and easy way of how it worked this is a little bit more wellth thought out way now you also want to know if I'm if I'm pulling a maximum of 2,000 watts and I divide that by a 12vt nominal system that's going to mean that at maximum capacity of 2,000 watts output it's going to be pulling some somewhere around 166 amps or something like that so we need to make sure we're using appropriate gauged cable for up to 166 amps so that's why this is two a cable it's rated for up to 200 amps and it's always better to over gauge than to under gauge so uh the the problem with under gauging is if I put uh you know if I put 10 gauge cable up here that's uh rated for about 30 amps and now suddenly I'm pulling 100 amps out of this thing I've got problems because it's not going to take very long for these cables to get overwhelmed by the current they're going to heat up the insulation is going to melt off and I could cause a fire very quickly so you want to be very careful of how you do that now fusing is a is something that is confusing to a lot of people sorry that was bad and where the confusion happens is a lot of people think that the fusing is specific to the equipment that I'm connecting to and it's really the fusing should be matched to the cable that you're using so you should always have a fuse uh from your battery array or your battery bank and the fuse should be as close to the battery as possible so don't put it on the other side of 10 foot of cabling uh put it right next to the battery and I've got my fuse right down here this is a 200 amp fuse uh specifically because I want to make sure that uh because these batteries can both produce 100 amps continuous that's 200 amps total I want to make sure I'm fuse to not allow it to really go past that I could get away with a 250 amp fuse here which would be a little bit better um simply because um when you're when you're protecting your cables a 2 O cable is rated for 200 amps and a 250 amp fuse would would be an appropriate fuse level so that uh I am I am giving myself a little bit of head room I'm not getting nuisance fuse blows or breaker trips for example now you should also when you're um and we'll take a look at solar panels in a minute but you should also have a disconnect for your solar panels and be aware that when you're using Breakers they need to be rated for DC in a system like this these are all DC Breakers or DC fuses and uh DC Breakers are different than AC Breakers because when you disconnect power you pull together uh leads from a DC you don't have the alternating current going back and forth and therefore the arc that that can produce when you're cutting the power can actually be harder to extinguish than it is in an alternating current system so that is why you want to use DC rated Breakers specifically for a DC system so don't mix and match those it's not appropriate all right but you definitely want to have a two-pole disconnect so you want to for your solar panels disconnecting both the positive and negative at the same time now everything else can be fused off the positive lead only really um there's no reason why you couldn't use a dual pull Breakers there if you wanted to but it's not really necessary um so I've got a battery disconnect here always very good to have uh so that you can emergency stop any power going to the rest of the system from the batteries if you need to uh which just a single flip of the button I've also got a little breaker disconnect here for my uh charge controller and that is because if something goes Haywire in the charge controller I don't want it just dumping uh Power from my solar array uh I want to make sure that I have an appropriately sized breaker there and again appropriately sized based on the gauge of wire now this particular um this particular charge controller has a max of 10 gauge that it can handle in there because it is only supposed to Output 30 uh 30 amps so I have got a 40 amp charge or breaker here which is passable um I might I might actually wouldn't want to make it just a little bit a little bit lower than that in terms of amperage rating where it trips but 40 amp something I can get away with here I used a little thicker gauge cable here it's like I said it's not there's no problem using larger cable the problem is when you're using smaller gauge cable I mean and remember smaller gauge means bigger gauge number so a a 10 gauge cable is a much thinner cable can handle less current than a two gauge cable so do make sure you keep that straight and I would highly recommend really making sure that you're totally comfortable with uh how the you know these basic calculations and uh current and cable relationships are before you get into this because you can hurt yourself you can set up something that is a fire hazard or a shock hazard and you definitely do not want to do that so take your time and do your homework and make sure you've got it right so what kinds of things can you do with a system like this well you could use it to to run a power for a small shed anything up to 2,000 watts and that's going to be most power tools will run on 2,000 Watts or less um you could use it for backup power for a refrigerator or freezer um and or just you could run actually I run a DC fridge in here almost non-stop um you could run an AC fridge with this system as well and especially if you've got basically uh five or 2500 wat hours of power um and as long as you got some sun you'll be able to keep that thing running pretty much indefinitely here um and certainly 2,000 watts is enough to run uh those kinds of devices now I do have a Google spreadsheet if you want to find out how what other kinds of things you can run for how long I'll put a link to that in the description below if you're interested in checking that out I'd highly recommend downloading it and then tinkering with the cells uh once you get it on your computer um but it's uh it's very straightforward you type in uh what the capacity is of your AC inverter you type in what the wat hour the rated wat hour capacity is of your um uh battery system in this case you got 1280 W hours time 2 so whatever that comes out to uh 2,560 wat hours um and and you type that in it'll list you what the runtime is and the kinds of things it'll run kinds of things that won't run so you get a get a feel for that if you find the helpful go check that out in the link below now a cool feature that I I didn't mention before that is available on both this uh particular 2000 watt um AC inverter and also on this charge controller there's a solar app that uh bouar V has for these devices and I'll P put that up on screen here so you can take a quick look at it but if I look at the one on the inverter I can connect to the inverter first and it'll show me uh the current operating State whether it's in eco mode eco mode basically shuts down the inverter and just does a basic very very small uh trickle current draw until it detects that a load is asking for power and the the that allows you to keep from leeching Power uh at a at a more aggressive rate if you just leave it on all the time so the only downside of using the Eco Mode by the way is that uh sometimes when you add a load it might take 10 or 15 seconds before it detects the load and flips itself on and then starts powering that load so just be aware of that um but it I think it's a good trade-off because it it keeps you from uh just sort of leeching power un necessarily for not actually pulling power out of the AC inverter um but I like that you can you can see all that you can set some parameters right there in the app now if I switch over get out of that and go look at the app for the charge controller um I'm able to see what the current battery uh voltage reading is like I can see actually off of the AC inverter as well U but I can also see what my current charge rate is on this charge controller and I can can actually go into the parameters that little uh that little gear icon in the upper right hand corner and I can set all the battery parameters and I would say it is much much easier by the way if you get this charge controller to set that using the Bluetooth app the mobile app than it is to go here and mess around with the uh the menu system because the menu system is uh is a little it's it's a little hard to figure out at first you got it's it's really easy to kind of get lost it kind of resets itself back to the first menu and you have to keep paging down to find out where you were if you're setting multiple parameters if you do it from the Bluetooth app and then just save it it is so much easier and so much um quicker and just less confusing I will say that so if you're going to get this make sure you get the mobile app to to do the configuration not required if you're worried about signing up and giving somebody your account information um you know having to sign into another mobile app it's absolutely not required to use this this particular charge controller you can all do it all from here but it'll take you five or 10 minutes to kind of get the feel for how to how to make your edits and save them back to the device so but yeah anyway it's it's a nice charge controller I like the fact that there's that there's a bluetooth app for both of these just makes it a lot more usable so let's talk about solar panel sizing and how maybe over paneling might be a solution what is that uh how does that work and what is the advantage so let's go jump outside and take a look at that all right got a couple solar panel options here for this test so over here on the right this this is the new 400 wat 10 busar solar panel from BGE RV and it outputs somewhere in I want to say around 37 volts or so uh open circuit and then I've got a series of four 200 watt solar panels here and these are also from B RV and these put out about I don't know about 22 volts each voltage open circuit and if we were to put these all in series that would give me a volts open circuit number number of somewhere very close to uh 100 volts so probably just slightly under 100 volts so we have to be very careful about that because we don't want to fry our charge controller we need to be cognizant of our charge controller's limitations but if I were to do a 2 s2p configuration which is in fact what I've done at the moment you can see I've got a couple of these little uh parallel Branch adapters here now these are also happen to be from B you can see the label there but basically I've got uh two panels here strung in series and then the other two panels strung in series and then I have these parallel connectors stringing these two series uh strings into parallel um back to my main charge controller so basically what's going on is we've got these two 22 volt uh panels strung in series and then the other two strung and Series so that is two separate 44v series strings and we're connecting them in parallel which is still still going to keep that voltage the same at around 44 volts but if you notice the uh open circuit or shortcircuit current rating of around 12 amps up there that will double because we'll have uh 12 amps for each series string so we'll end up with about 44 volts and uh roughly about 24 amps so keep in mind if your charge controller doesn't support let's say it caps out at 20 amps well you won't be able to quite Max maximize under ideal conditions you won't be able to maximize the total output voltage I wouldn't be able to get for example the 800 watts now uh yeah well and we're going to talk more about that in a minute so just be aware of that now since that bouar V 30 amp sunlow charge controller um actually has a limit of about 450 Watts total when you're operating on a 12vt system which is how I've got it set up and it will support a 24volt system also so but I'm using it in 12vt mode and it does autod detect that by the way um so what what I'm limited here I will I'll be able to connect this particular panel because it is well under the maximum 100 volts and it should allow me to get the most out of this panel which is a 400 W panel now even if I could string these four panels together in such a way that I'm staying underneath that voltage Max which I think is 95 volts approximately on that charge controller um I would still not be able to get the full 800 watts out of this 200 watt by4 array and that is because of the uh input current limitations of that charge controller but the question is on cloudy conditions and this is what I want to see on cloudy conditions if I were to over panel that charge controller in other words put more than 450 watts of solar on it under the same cloudy kind of uh conditions will I actually get get and how much more uh charging power will I get out of a 800 WT array by over paneling versus a 400 WT array let's go see how that works all right now real quick let's just take a quick look here I've got the 400 watt panel hooked up right now and I'll pop up the app and you can see that I'm pulling uh just about 111 Watts 109 Watts from that 400 watt panel and that's because the angle's not great and there are a lot of clouds in the sky now we have over paneled also here that 800 wat array so let me just hook that up real quick and we'll see the difference that over paneling gets us even though I'm never going to get the eight full 800 watts out of that array but take a look at the app now with the 800 watt array connected now obviously you expect more power out of an 800 watt array but uh the problem is is that because this maxes out at 450 Watts with a 400 watt panel even in the best of conditions I'm probably not going to get more than 400 watts you know it would be very unusual even to get 400 watts I might get 380 Watts or 350 Watts much more commonly in pretty good Sun but on a day like today I'm only I'm only getting much much lower than that maybe a quarter of its rated output but look how much output I'm getting out of the 800 watt panel uh even in the even though the sky conditions are not nearly as uh conducive so I think that over paneling is actually a good option especially from a cost standpoint because it's much less expensive to add solar panels than it is to add battery capacity and over paneling 20 to 25% beyond the watt rating of your charge controller actually will help you maximize your solar input in less than ideal Sun conditions so I think it's something to consider if you have the extra room in your budget all right like I said this is not a sponsored video but if you're interested in any of these particular products B RV is a nice One-Stop shop kind of place to get this kind of stuff so they do sell solar panels you can buy them individually rather than buy having to buy them in you know large pallets which is nice especially if you're buying something in the you know 200 to 400 watt range it's um it's nice to only be able to buy a couple if that's what you need for a small backup power solution um and then they have a couple different types of batteries as well they have a multiple types of inverters they have multiple types of charge controllers um so highly recommend you go check them out I'll leave links to the ones that I'm showing you here in the video description below if you want to go check those out as well uh but they are available I think mostly on Amazon and also on b b RV's website and for some reason I think they're a little bit cheaper on Amazon for the most part than than they are direct on the website but um and I might have a discount code I'm not sure if that discount discount code Works U I'll try it out if it does work I'll leave it in the description below as well um but like I said this isn't a video that B RV asked me to make I just had all the components and I thought might be interesting to do a walkthrough with you in case this kind of stuff is something that you're interested in learning more about anyway thanks for joining me I hope you found some of this useful if you did please consider hitting that like button for me really appreciate that and I do hope you'll consider joining me for the next one until then have fun out there

Channel: ReeWray Outdoors

Views: 40,291

Keywords: off grid solar, rv solar, diy solar, solar battery, off grid solar power system, how to, van solar, offgrid solar, solar setup, how to build a solar power system, diy solar panel system for home, will prowse, diy solar system

Id: PG7RzOyj3ME

Length: 21min 11sec (1271 seconds)

Published: Sun Feb 04 2024