Build Your Own 12-Volt LiFePO4 Battery For Cheaper Than AGM

today the time has finally come to switch to lithium let's get started [Music] what's up everybody welcome freely roaming my name is dan so two years ago a little over two years ago about two and a half years ago when we started building our sprinter van we decided that we're going to stick with lead acid agm batteries for the time being because at the time batteries lithium batteries were still very expensive they were becoming more popular and a lot of people had already switched back then i wouldn't necessarily call the people that switched the lithium early adopter because the technology has already been very mature it's just that the prices were still very high because for a long long time lithium batteries specifically the ones that i'm going to show you today lithium iron phosphates were exclusively used in industrial applications like backup generators for cell phone towers telecommunication devices was a very popular place where these were used because usually they're unmanned and they had to be running 24 7 regardless of power outages and they had a really long lifetime so a lot of people were taking the technology and the products that were created in the telecom industry and repurposing them because they worked really well for 12 volt application at the time two years ago to get a 100 amp hour battery was gonna cost you about a thousand dollars and that is um sort of a drop-in replacement that was built by a battery manufacturer designed to be used in an rv or boat or some kind of 12-volt replacement application now those prices are still pretty much the same they've come down a little bit i think a battleborn battery back then was about a thousand dollars and now you can get them for about eight nine hundred dollars and there's other competition that come online that sell batteries in that size range for that type of chemistry for about six to seven hundred dollars for 100 amp hours which is really great that's come down about 20 to 30 percent and in some cases even more depending on the quality but where lithium iron phosphate batteries have really thrived is in the diy world a lot of companies have come out with diy kits that allows you to build your own lithium iron phosphate batteries they're not necessarily any different than the ones that you would have found before it's just that there's so much competition now so many people are adopting and seeing the benefit of lithium batteries you can get them for really really cheap two and a half years ago when we built our van instead of going and spending the money and buying lithium components or buying a ready-build lithium battery we decided for the time being to go with agm and we went with v-max we went with these six volt v-max agm batteries that had a 225 amp hour capacity and they were 280 dollars each they're still 280 each the prices on agm batteries haven't changed they've already been around for decades and they are at probably as low of price as they're going to be and there's even a chance i think for lead acid batteries to go up in price kind of like you know digital cameras have replaced film cameras and film prices have gone up because there's less demand so we paid almost 600 dollars for a pair of two batteries and that is because it's agm lead acid we only get to use about 50 depth of discharge for this battery chemistry so it was only about a 112 amp hour usable so it was still cheaper at the time 112 for 600 was still cheaper than 100 amp hours of lithium at a thousand dollars but fast forward two and a half years now let me just show you what i got these aluminum encased lithium iron phosphate cells and this is 280 amp hours this is a 280 amp hour cell and i got four of these and with four of these at a nominal voltage of 3.2 when you serial connect four of these together you get a perfect 12 volt replacement has a nominal voltage of 12.8 which is exactly what you want for four of these you can buy them on aliexpress you can actually buy them on amazon too i'll put some links down in the description you can get these for less than a hundred dollars a piece and since you need four of these it'll cost you about between 350 and 400 depending on what you buy them now which one and what supplier you buy these from is really important because you want to make sure you're buying brand new cells even though these look brand new you still have to be really careful you have to make sure that they're serialized that they have this qr code you can scan and find the the actual information about each of these cells you want to visually inspect them you want to make sure that they are well matched when you get for these cells it's really important to make sure that these four cells that you're getting are of the same manufacturing date or of the same batch because lithium unlike lead acid for a lack of a better word they are they're more fragile meaning that you have to take better care of them lithium batteries they require a lot more complexity in the operations that's probably the number one biggest downside they can be used in really cold situations and they have to be really well balanced they can be damaged if you overcharge or under charge them of course you can do that with lead acid too but with lithium batteries the damage is much more severe and depending on the chemistry you could have thermal runoff which can cause fires and extreme heat in sometimes injury and possibly death if you're not careful i was really happy to get these i'll tell you guys where i got it from with the link below but because i'm here in europe right now it was a little bit more expensive for me to get them but i felt like the time was right the time was right to get lithium batteries to replace my two and a half year old existing agms even though those agms still have probably because i take care of them i never let them go too far too far down in the discharge cycle and i never overcharge them i use a really high quality mppt charge controller to make sure that they're charged properly they probably have another five to seven years of life left but the advantages of going lithium iron phosphate is that they're going to be less than half of the weight for the same amount of usable amperage these are going to give me 280 amp hours which compared to my 225 amp hour lead acid these are going to have more than double the capacity and they will at the end of the day they will probably just slightly lighter not significantly lighter maybe 60 70 percent of the weight of my current two lead acid batteries the recommended range for these battery is to never discharge them to less than 10 and never charge them to over 90 percent so i have about 80 percent of usable range safely because you also want to take care of these so 280 amp hours between 10 depth discharge to 90 depth of discharge you're looking at 224 usable amps and that is actually almost exactly doubling what my agm because my agm is rated at 225 amp hours and i'm able to use half of that so i'm doubling the usable capacity and i'm at lower weight not exactly how much lower it's going to be yet but we'll find out when this is all assembled i've got some other parts i want to show you that i'm going to use to put this battery together and i'll go through just briefly what each of them are and there's going to be a follow-up series of build videos that will show you exactly how i put them together how i drop it into the existing battery location and how it all hooks up to the existing system that's currently using agms so let me show you how this battery came i'm going to take three of these cells out that i've already opened and show you they each came individually packaged actually the four cells came in a big box like this i was really impressed at how well it was packaged as you can tell the corners are even reinforced so they don't dent as easily but i was wondering why they only did three corners and not this fourth one maybe they just forgot but fortunately for me there was no damage to the box at all inside the box it was again well padded with nice thick foam all the way around and also this thick foam was used in between each individual cell when it came packaged and each battery again came in its own box when you open it they're each individually foam padded once again on all sides and that's what one of them looks like besides the four cells i also got five really thick copper bus bars they're nickel plated copper bus bars to prevent corrosion they're really nice and thick they're nice and thick you can tell they're copper with nickel plating it's really nice and thick the way that i'm going to connect them which is four in series i'm only going to need three so i have two extra ones they give you five just in case you want to connect them in parallel depending on how you plan on configuring them you may want to purchase or ask for more bus bars which you can do when you order them just say hey look this is how i'm going to configure it i'm going to need x number of bus bars so if it doesn't come with enough you can buy it from them and also it comes with the hardware which are just stainless bolts and washers that lets you connect them to the top one of the downsides i've heard about these cells is that the terminals are not particularly strong then they can't be stripped so you have to be a little bit careful but upon close examination there are no dents there's no damage to any of these cells and i did do a voltage test there they all come in at about 3.2 volts and they're very closely balanced so i'm really happy about that you can find these for under 100 a piece which means between to buy for them you could have them for less than four hundred dollars i've seen listings at aliexpress for a batch of 16 of these for as low as 1200 which is an unbelievably low price so that is actually cheaper than what i paid for my agm batteries at double the capacity but that's not the whole story because even though you can just connect these cells together and use them right away over time when they're new it's not a big problem it's rarely that they'll go out of balance if they come with a match set from the same manufacturer over time as they age they can go out of balance and that's why i need the battery management system in a battery management system i chose is is this one this is the dolly common port 4s 12 volt bms and it's rated for 120 amps so the way that you set this one up is you connect your cells together and then you connect the negative to the bms and then this other negative that comes out of the bms becomes the negative that goes to your system so this battery management system will monitor your individual cells voltage to make sure they don't go out of balance if they do go out of balance this is a bms that has a balancing feature that will try to automatically balance them because what happens when your cells go out of balance is that as you charge them or discharge them the charger can only see the overall voltage of the entire pack and the charger is going to attempt to charge them to a certain voltage and if one cell has a higher voltage than the other one then they're going to come up together when the low one is not fully charged yet the other one that's overcharged because it started out unbalanced and higher you're going to end up damaging the cell that has the higher voltage and the same goes for discharging when you discharge batteries if one is higher if one cell is higher voltage and the other one is lower voltage as you discharge them the battery is going to discharge to a certain voltage overall voltage before they stop and what will happen is that the one with the lower voltage the lowest voltage is going to get far below its recommended lowest voltage setting you damage that battery so it's important to make sure your battery or your cells are balanced and that's what this is going to do and sometimes people will say well you know bms's are good at cutting off charging and discharging when it senses some kind of trouble they don't do a very good job at balancing i think this one will this one is pretty heavy duty but i also got just an active cell balancer this is kind of a controversial product a lot of people say you don't need it and some people say hey you know what's the herd of having one well we'll see i picked one up just to check out to see if it's worthwhile trying so i will put this system together within the next few weeks and test it out and get back to you guys on just exactly what i think of it so i have just about everything that i need to start putting this lithium battery pack together for me with all the stuff that i ordered it cost me a lot more to have it sent to europe where i currently am right now but if you're ordering this from the us these four cells you can buy them for about 380 in this bms you can buy different sizes i chose to go with one that's rated at 120 amps because i'm not gonna go over that 120 amps that's about 1500 watts of output there's nothing in my van that draws 1500 watts not yet anyways maybe i'll have to upgrade those when i decide to switch to induction cooking but even at 1500 watts you can get most of your cooking done on a lower setting of an induction cooktop and still be able to use this the newer version of this also has a bluetooth port mine does not i think that bluetooth model just came out you can buy one with a bluetooth output and a bluetooth dongle that lets you check all your data from the bms individual cell voltage overall cell voltage um the different errors that it's producing through a mobile app which is pretty cool but unfortunately when i bought this a month ago it wasn't available yet you can buy one of those for about 90 to 100 depending on if you get the bluetooth module or not bms lithium cells you can get everything that you need to build your own lithium battery today for less than 500 which is pretty amazing because that's less than what i paid for my agm batteries two and a half years ago so i hope you guys enjoy this video i wanted to show you guys my next project and if you guys want to see exactly how this battery is going to go together and how it's going to be installed in our van don't forget to subscribe down below if you have any questions ask them in the comments and as always thanks for watching i'll see you guys in the next one [Music] you

Channel: Freely Roaming

Views: 325,903

Rating: 4.904891 out of 5

Keywords: travel, nomadic, digital nomad, financial freedom, home school, travel guide, minimalism, full time travel, overlanding, van life, financial independence, fire, road school, rv living, passive income, investing, nomadicism

Id: IsvBlQJr7b0

Length: 17min 0sec (1020 seconds)

Published: Tue Nov 10 2020