Wiring Batteries for Solar

in a prior video i went over different types of batteries that we use in our solar water pumping and other off-grid systems this is mike with rps solar pumps and today i’m going to tell you how to wire up your batteries whether you’re doing a 24 volt system or a 48 volt system i’m going to demonstrate that with both of these 55 amp hour and these much larger 160 amp hour batteries if you want to know how to wire up your batteries stay tuned i’m going to go over the different configurations and how to wire them in parallel or series depending on your exact voltage and current needs let’s talk a little bit about deep cycle battery basics down below you can see two different sizes of batteries on here we have a 55 amp hour gel battery and over here we have a much larger 160 amp hour gel batteries other types of batteries we use in solar systems are deep cycle flooded lead acid we also use what’s called agm absorptive glass mat and in this case we’re using gel gel batteries are great for outdoors they are capable of deep discharges and they have a long cycle lifetime so they’re going to last several years on the field now both of these are 12 volt batteries and that’s going to be the most common battery you’re going to see when doing your hookups they also have 6 volt batteries if you’re using a 6 volt battery then basically all the stuff we’re talking about is going to be doubled and we’re going to use twice as many batteries for any of our connections these two are fundamentally the same the main difference is the size of the battery the larger battery is going to have much more current capacity than this smaller one but we can also make up with a smaller one and add more batteries in parallel to basically make an equivalent large battery bank these are 12 volt batteries so when we’re talking about a 24 volt or a 48 volt system we’re going to need to add those in series in order to hit our voltages so when we connect batteries in series we’re connecting the positive terminal of one battery to the negative terminal of the next battery that’s a serious connection when we do that connection the voltage is going to be additive for each battery we add so if we have two batteries in series we’re getting 24 volts if we have four batteries in series we’re getting 48 volts now we want to increase the current capacity of a battery bank we add additional batteries in parallel when we do a parallel connection it’s the opposite we connect positive of one side to positive other side that’s not gonna add the voltage it’s gonna increase the current capacity of that battery if that sounds a little complex don’t worry the connections are very simple i’m gonna go through wiring both our small batteries and our larger batteries with the smaller we’ll just show a 24 volt configuration and a 48 volt when we’re using these larger batteries majority of the time we’re using them for 48 volts systems and so i’ll show you how to make those connections and then if you’re increasing the capacity of your battery bank i’ll also show you how to add additional sets of batteries in parallel in order to increase the capacity one of the great things about these battery bank systems is you can start with a smaller battery bank and if you find your usage a little higher than you’re expecting you can add additional sets of batteries in parallel in order to increase the capacity of your overall system so let’s jump in we’ll start with the small batteries and we’re going to show you a 24 volt and a 48 volt connection before we get started here let’s talk a little bit about safety so these batteries contain a large amount of current and they can release that current very quickly if we happen to short out the positive and negative terminals if those terminals short against a metallic object like a wrench or like your wedding ring here it can quickly heat it up to red hot and if it’s your ring it’s going to burn your finger if it’s a wrench you’re holding it’s going to hurt and possibly burn your hand so when we’re working around these batteries we want to be careful that we never short the positive and negative and it’s best if we remove any jewelry while working with a battery like this also with the majority of batteries you’re going to get these little rubber grommet covers these go over the end of your battery terminals this makes it so if you accidentally drop a wrench or something else on there you’re not shorting out those terminals today i’m not going to hook all these up but when you’re working with jumpers you do want to put your jumper through your rubber grommet when you make your connection and then when you’re done cover up that connection here the nice thing about them is they have a hole in the top that allows you to still take voltage measurements to the top but prevent shorting out in your terminals so like i mentioned i’m not going to use these today so it’s easy to see all the terminals but when you’re doing your final setup add these on for safety and if you happen to have any accidents dropping tools it’s going to save you a lot of grief using our smaller batteries which are 12 volts each let’s start with the smallest building block of our 24 volt system that’s putting two 12 volt batteries in series there’s a diagram up above here which shows how we’re going to make the connections for our complete 24 volt battery bank i’m going to start with the two batteries and as you saw in the diagram the jumpers we’re going to use for series connections in this case are blue the series connection is going to be from the negative of one battery to the positive of the other battery like i mentioned before that’s going to increase the voltage we’re going to add 12 volts plus 12 volts to get a 24 volt battery bank i’m gonna wire up the series connection right now

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so as you can see now we have two exposed terminals we have a positive here and a negative over here between these two terminals we have 24 volts for our 24 volt battery bank if you’re only using two batteries for your system then you can put your jumper wires from the plus and minus into your controller whether it’s an rps three-inch pump controller or whether it’s a tpp water secure or anything else you’re hooking up to now if you’re using more than two batteries and you’re going to go to a four battery system on 24 volts then the next connection we’re going gonna make is in parallel when we’re doing parallel connections we always have to have the same number of batteries in series so if we have two batteries in series the next set need to be two batteries in series for doing a 48v battery bank with four batteries in series the next set has to be four batteries in series we can’t mix and match we can’t do a 48 volt system with four batteries in series and then the next set with two batteries in series that’s not gonna work we always have to have the same number of batteries in series when we’re expanding out the system let me grab two more batteries and we’ll show you how to do the series connection again and then our parallel connections so we’ve added two more batteries up here when i lay out my batteries i always like to lay them in the same orientation that means over here on the right side i have our positives and over here on the left side i have our negatives when we’re wiring up it makes it much easier because we can go right across the battery terminals so let’s do our series connection real quick

great so we have our other series connection in this battery bank right now we have two sets of batteries in series these two in series and these two are in series we want to stay with a 24 volt battery bank in this case so we can’t do any more serious connections because that would increase the voltage now we need to do our parallel connections

so using a red jumper we’re going to jump our two positive terminals together and then using our black jumper we’re going to jump our two negative terminals together

so now we have our two parallel connections on the positive and the negative side now this can get a little bit confusing if you look at the battery bank there are no open terminals we still need to connect our wires going up to either our charge controller or up to our control unit for our solar pumps we do that with these now we can attach these cables to either of the two terminals it really doesn’t make any difference so pick the terminal that’s more convenient and hook up your positive to the red side and you’re negative to the black side and when we do this now we’re going to have two wires on one of the terminals

so now we have our two leads and these can go into our control box for a solar pump into our inverter or into a charge controller that’s going to charge the batteries off of solar so the series and parallel connections for a 24 volt battery bank are that easy this is with four batteries if you have six batteries you would add two more over here wire them in parallel and the series connection and that’s going to add two more batteries into our system we can keep adding on to that as many batteries as we need in order to increase the current capacity of the system while maintaining our 24 volts which our system’s expecting with our 24 volt battery bank setup let’s talk quickly about the wires we’re going to use in order to run from our battery bank over to our controller it’s always best to keep your battery bank as close as possible to the controller in order to minimize voltage loss then the gauge of your wire is going to depend on the current draw of your load so in the case of our three inch pumps that we’re running on batteries that load is around 10 amps or so so that means we can use anywhere from a 12 gauge to a 10 gauge lead and that’s going to make it nice and easy in order to hook that wire up into the terminals of our controller if you use a thicker wire it can get a little bit more difficult to get it in the screw terminals in the case of our tpp systems those are drawing a bit more current so we do want to go to thicker wires these are six gauge wires which work very nicely with the amount of current draw from our tpp systems

when we step up to our water secure systems they end up drawing quite a bit more current from our battery bank anywhere from 50 amps up to 100 amps plus so then we want to start going to much thicker wire these are two gauge wire and they’re suitable for carrying that amount of current so there’s not much more to it than that in general if you’re unsure it’s always better to go with a slightly lower gauge and thicker wire than a thinner wire in order to minimize the voltage drop between the battery bank over to the controller the same goes for the jumpers we’re using on the batteries here the jumpers in general we just match to the same size gauge as the leads from the battery bank to the controller to make everything nice and simple and uniform so that was the basics of a 24 volt battery system where we do two 12 volt batteries in series now let’s talk about a 48 volt battery bank when we do a 48 volt battery bank like the diagram over here shows we connect four 12 volt batteries in series when i lay out my batteries for this i like putting them all in one long line while it is possible to wire them like this it requires us jumping around and it’s not as clear-cut as if they’re all in one long line so if you have the space i always recommend lay out your 48 volt battery bank in one long chain and so i’ll reconfigure those to get them all side by side

with our batteries laid out we’ll first do our series connections there’s going to be three of them here here and here and we’ll do that with our blue jumpers

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with our three series connections now we have 48 volts between our positive and our negative post here from here we can attach our wires to go to whatever controller we’re using now if you want to do another set in series we simply line up another four batteries here we do our series jumpers and then we use our parallel connections again same as the 24 volt system we go from positive to positive and we go from negative to negative on this end that’s again going to increase our current capacity of our battery bank while maintaining the same 48 volt configuration it’s that easy we can keep adding on parallel sets in order to increase our battery bank size so that’s it for our smaller battery banks whether we’re doing a 24 volt or a 48 volt system we use the building blocks of both series and parallel connections to build up for the required voltage and capacity of our battery bank i’m gonna go show you how to wire up a 48 volt battery bank using our large batteries it’s exactly the same with our series and parallel jumpers it’s just a little bit bigger and in that case we’re probably not going to lay it on one long big chain it’s going to be more of a square and we’ll jump around in order to do our connections we have our much larger 160 amp hour battery bank set up here we’re going to show you a 48 volt configuration so it’s gonna be four in series and it’s basically the exact same as the smaller batteries we’re going to start with our series jumpers in this case we’re using our two gauge wires since this battery banks can provide quite a bit more current for our larger load

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so there we have our series connections performed connecting all four batteries now off of these two terminals over on the left here are positive and our right are negative we have 48 volts coming off of here if we’re using one set of batteries then we can use our other wires to go over to our load if you’re doing another set of batteries it’s the exact same thing we’re gonna lay out four more batteries we’re gonna perform our series connections and then we’re gonna use our parallel jumpers just like we did before to jump one battery bank to the other on both sides and then one of the two terminals is going to get an extra wire on it

to go over to our load

so as you can see it’s a very simple setup and configuration and like i’ve mentioned before it really helps if we just lay out all the batteries in the same configuration positives on the left here and the next set positives on the left makes it very easy to do all the series jumpers and our parallel jumpers so that’s the basics of laying out both a 24 volt and a 48 volt battery bank whether using the small batteries or our larger batteries it’s very simple makes it much easier if we lay it out in a nice uniform configuration and then make the same sorts of jumps for our series in parallel all the way down the line if you need some of these batteries they’re awesome gel batteries they’re going to last a long time out in extreme conditions give us a call at 888-637-4493 or visit us at rpsolarpumps.com we can help you lay out your battery bank and get you set up with a robust off-grid system