$433 280Ah LiFePO4 Cells Tested: Cheaper than lead acid!

today we're testing the cheapest lithium iron phosphate cells on the market the manufacturer is eve and these are 280 amp hour cells and for four of these it was only 416 that includes tax and shipping but we should not get our hopes up yet we need to test these because we have been ripped off many times before the reason they're so incredibly cheap is they are grade b cells but for the price i don't think you can beat them this is the most capacity for the price that i can find online right now but they have an intact barcode and on the side it says scratch for grade b if the terminals look nasty they will still call them grade b but i'm more curious if these will pull full capacity or not i really don't care what they look like especially at this price point these actually look pretty good for being grade b cells the first thing i look for is if there's any gaps between the cells because it shows that there's gasification in one of the cells and it's expanding and you do not want that these cells do prefer to be compressed so we're going to actually have to hold these together somehow now these cells are in a series configuration with positive negative positive negative and now we can add the bus bars uh-oh these threads are damaged this one doesn't feel very good either and this one actually went down all the way so we have one good terminal so the rest of the terminals were actually pretty good but these first two terminals that i messed with are very difficult we're gonna have to tighten these down yeah same with this one this one looks a little damaged on the top so i think if i tighten these down with an impact gun so if i tighten it down a bit more i think they'll be all right be very careful though it's very easy to strip these out you do not want to over tighten them before we add a bms let's check the voltages so pack voltage is 13.17 first cell 3.29 second cell 3.28 3.29 3.29 that's decent now we need to add a bms to this pack and so i bought a 250 amp dally bms how crazy is this this is a 4s 250 amp and it even has a cooling fan on it i guess we could mount it like this i wish this cable was longer so you could mount it elsewhere but the balance cable is very limited in size too so we have to mount it close to the battery look at how beefy this lug is compared to this terminal this terminal actually has enough surface area for handling the current that this is rated for giving it one see but it's just this tiny little screw and look how many threads we have to work with so actually i might go to the store real quick and get some studs because i don't like that this will absolutely strip out if i try to put that thing on here i mean look at how many threads we would have available so just got back from the store i couldn't find studs so we're gonna have to make our own that's dangerous [Applause] and do not over tighten that wasn't very hard but i really wish these came with studs instead well that feels pretty good yeah these all should be studs i don't like these at all i like how large these cells are it is easy to organize the cables for the positive terminal we're gonna use a four out gauge copper wire i do not like working with 12 volts look at these cables this is ridiculous all right that's the best i'm gonna get it's not moving and check it out guys we should be able to pull 250 amps with this thing so let's charge it up and do a capacity test first before i ruin these cells i want to ensure that these are pulling full capacity and then we can do high c rate discharge tests and before we activate this bms so we can charge it up and test it we're going to ensure that each conductor goes out to its appropriate cell third cell and for a cell because if you mix one of these wires up you are going to burn out this bms instantly and we have power so this huge deli works just like all the other smaller dalys you just have to short out b negative to p negative we're going to use an ames power 75 amp charger i do not like their inverters but i really like this charger i use it all the time you can adjust the current i need to make a review on this thing anyways let's charge it up we're charging at 70 amps which means it will take four hours to charge this battery to full into speed of charging i added a 60 amp charger oh crap i overloaded the circuit my bad we're charging at 127 amps you guys that's incredible and while it's charging at a fast rate let's test the voltages 3.47 3.47 3.47 and 3.5 so the first cell is a bit higher than the others oh and this bms is rated for 125 amps for charging current i did not know that so we're just above the limit so this is actually a really good test for this bms as well so the cells were a bit off so it took me a few hours to top balance these i used two different power supplies to charge up this cell in this cell and now they are the same voltage so now we can do a capacity test and check out how many chargers we have we have four chargers to get these cells up to full capacity and i'm gonna let them sit for just a minute and put the charger back on just to get that last bit of absorption for this capacity test we're not going to use the cba4 this would take 28 hours to conduct this test so we're going to use this instead and for a 0.2 c test we need to pull 56 amps at 12 volts the closest i can get is 51 amps so it's gonna be about six hours for this test it actually pulled full capacity you guys so five hours and 23 minutes 281 amp hours incredible i'm usually not prepared for when grade b cells actually pass the capacity test huh wow so we actually have a battery so let's test this thing let's charge it up quickly and do a fast discharge this is awesome you guys are in for a special treat because i bought an inverter just for this test we have a 4 000 watt 12 volt pure sine wave inverter and right now we're charging at 134 amps so i'll come back in a couple hours and then we'll hook up the inverter so it's been quite a few hours and it's pretty late but i really want to do this test so it's fully charged so let's fire it up and this inverter is huge so we're going to pre-charge the capacitors with this little resistor always attach the large conductors to the inverter first and then connect the battery i see people do it the other way around and that's very dangerous it's a negative conductor to the p negative positive conductor over here so let's charge up the capacitors we had no spark very nice but the weakest part of the system is these bus bars and they might be able to handle 250 amps but we're about to find out now we have 3 000 watts of heat gun power so divided by 12 volts that's exactly 250 amps 270 let's see how long you can pull this load for this is more than this bms can handle i'm surprised it didn't trip it yet actually these bus bars feel pretty good yeah this feels pretty good guys i think it's doing it just fine first five minutes and these bus bars are still warm but not hot it's still going guys after 16 minutes we are still solid and these bus bars are still holding up they are not hot they are only warm there we go oh my tape job didn't hold up we're at 280 amps so we're doing a full 1c from these batteries and the current is rising because the voltage is dropping and nothing's hot everything feels great 3.07 3.11 3.1 3.1 so this one is the lowest capacity cell it was the first one to rise quickly and it's the first one to fall quickly but it still pulls 280 amp hours so it's still past the test and this bms is only rated for 250 amps looks like the fan is on non-stop so there's a lot of heat generation right now 292 amps guys about 42 millivolts of voltage drop on these conductors oh this one's 111 millivolts and across the bms 247 millivolts the voltages are 2.9 2.8 2.8 2.8 and it disconnected when the fourth cell hit 2.4 so everything worked as advertised isn't that crazy that was a very impressive test and considering just what you can do with this size of battery and inverter is just mind-boggling so those test results were impressive and i do like these cells a lot of people on my forum have been using these for like the last few months and they absolutely like them but let's talk about the downsides first issue are these terminals they are very small and easy to strip out so i suggest everybody using studs and nuts instead of these little bolts that it came with next downside is the shipping speed is very slow it took about two months for me to receive these these are the last cells in my order from aliexpress and besides that these are pretty great they are the cheapest option these are like three to four times cheaper than other available options in the united states like 280 amp hours you guys it's incredible now let's talk about this bms i bought this with my own money on amazon so dally is selling large bms's now on amazon surprisingly this pulled more than its rated current capacity for an hour but some people on the forums are complaining that the new smart dahle bms does not work that great or it's hard to use so personally i like to stick to the simple daily bmss that are not considered the smart ones and they do not have temperature sensors because they've never given me a problem ever this one is no exception this one worked perfectly but would i trust this on a large system absolutely not i would personally use something else also you should never ever have to use this much current you should absolutely put these batteries into series for a higher voltage and use a higher voltage inverter i just wanted to push this much current just to see if it could handle it and it actually did which is pretty incredible and that's pretty much it i hope you guys like the video i'm pretty surprised that the cheapest products on the market actually work really well so i will talk to you guys later if you want to see some of these products i'll have some links below also to the charger that i've been using i really like that thing so yeah i hope you guys like the video and i will talk to you soon bye

Channel: DIY Solar Power with Will Prowse

Views: 698,421

Keywords: off grid solar, will prowse, diy solar, rv solar

Id: 3U4ZfQ_IToI

Length: 11min 10sec (670 seconds)

Published: Fri Jan 08 2021