EASIEST DIY 12-Volt 280Ah LiFePO4 Battery // Step-By-Step Build

#ModernNomad #MobileLiving #VanLife
Prismatic LiFePO4 cell prices have once again come down. Even with the wide-spread popularity of cheaper-than-ever, commercially-build lithium packs, you can still build your own for a lot less. I mean like 35% less and with all of the high-end features such as low-temperature cutoff and Bluetooth app connectivity. In this video, I will show you how I built a 280A pack for less than $700 and where I sourced all of the parts.
Buy 280Ah LiFePO4 Cells from Shenzhen Qishou Tech
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Timestamp:
00:00 Introduction
01:15 Should You Build One?
01:56 Is It Still Worth It?
04:05 Building A DIY LiFePO4 Pack
05:13 Packaging, Shipping and Contents
07:30 Inspecting Battery Cells
08:56 Battery Management System
11:08 Misc. Other Parts
12:16 Pack Assembly
15:29 How To Connect The BMS
19:52 Testing A Completed Battery
22:18 Bluetooth App for BMS
26:10 Conclusion
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[@freelyroaming]

Prismatic LiFePO4 cell prices have once again come down. Even with the wide-spread popularity of cheaper-than-ever, commercially-build lithium packs, you can still build your own for a lot less. I mean like 35% less and with all of the high-end features such as low-temperature cutoff and Bluetooth app connectivity. In this video, I will show you how I built a 280A pack for less than $700 and where I sourced all of the parts. Buy 280Ah LiFePO4 Cells from Shenzhen Qishou Tech www.alibaba.com/product-detail/Grade-a-lifepo4-3-2v-280ah_1600551390417.html?spm=a2747.manage.0.0.73e871d2RVwOMi Buy RadioB Tech 120A BMS: amzn.to/39OYgYA My Preferred LiFePO4-Compatible Smart Charger: amzn.to/3A2eeJq

[@johnnyb3726]

I am a very novice LiFeP04 guy looking for the best, most cost effective solution for my needs...This video was excellent...How many cells can you actually add to that BMS and it still work? I have a truck bed camper and want to max out the AH for the space I have available. So can you build a 400 AH battery this way, using the same parts, just more cells? and do you have any other forums you are a host/member of that i might be able to sign up for?

[@freelyroaming]

Johnny, I offer coaching sessions here freelyroaming.com/coaching

[@menglei6301]

This guy is awesome, thank you so much for sharing. I used to buy a lot of ADCBATT 100ah lifepo4 batteries and although they are not expensive and still work, I plan to make one myself.

[@robertboyer5498]

I thought that the cells from Ali express were b grade junk? I’ve heard several people never even got their batteries. Now, these were complete batteries, not cells, so maybe it’s different?

[@freelyroaming]

@@robertboyer5498 AliExpress is a platform with thousands of independent sellers. So the quality varies from each one. You can not blanketly assume anything across all of them.

[@i_know_nothing7788]

No wedding rings, metal watch straps or metal necklaces was what we were taught working on electrics.

[@youtube_dj_65]

I am a professional electrician for over 40 years. I immediately teach my students to take off the wedding ring. If you somehow short circuit with your ring on. Suddenly an arc flash! Safety first. I have known people who have been hospitalized for weeks!

[@markgerloff7928]

I've seen this happen to a co worker working on a Harley 🤣 goodbye skin! Gnarly

[@billcollins7009]

That happened to my brother. It was a nasty injury!

[@Bozemanjustin]

Yes, I'm sure that's what you tell the wife when she finds your ring off.....lol

[@RaafatALBadran]

Staying in hospital rather upset the wife is more effective 🤪

[@dogfood61188]

Place I used to work a guys wristwatch shorted between a vehicle chassis and the positive of the battery. It got very hot very quickly He got 3rd degree burns all round his wrist.

[@ReviewsandTech]

WOW, nice and simple build one of the best to be honest and straight to the point, and yes LifePo4 batteries are the best I am glad you went with the Eve brand as I have heard a lot of good positive feedback from other folks too, thanks for sharing man, cheers.

[@s.mendez7160]

Simple video, easy to understand. Glad you suggested to beginners to watch other more detailed assembly and test steps.

[@mceepee]

Thank you, very impressive! I'm picking up off-grid trailer soon and this build will be the perfect addition!

[@chinoodin4735]

Nicely done, straight forward, simple to follow by design. Thanks for sharing the education. I’ve got 16 cells 100ah that need a Bms to construct either a 12, 24, or 48v battery. This has been very helpful in understanding what needs be done to continue. 👍🏼

[@FrankVelo]

Best thing I ever did! Going to build out a second one this fall I think so I can run my AC on an inverter.

[@mingo0817]

Thanks for the tutorial. Was debating whether or not to get off the shelf stuff. But this seems pretty straight forward and has more potential.

[@steinanderson9849]

nice pun!

[@LiquidTurbo]

This is a fantastic video! Thank you for making this. Gives me the confidence to try it.

[@JohnP58]

Great tutorial, can’t be more explicit. You got me. Cheers

[@kybrancaccio]

Nice job! Thanks for making this video.

[@TRYtoHELPyou]

i bought 4 cells back in i wanna say 2020.. and just got that same exact bms recently. works well. very nice build dude!

[@freelyroaming]

Thanks man. Love this BMS!

[@headdown1]

Excellent video! Exactly what I was looking for. Thanks for taking the time to make it.

[@pauljconroysr4080]

thank you very much for this it has helped a great deal and very concise ,direct,well explained , and easy to follow .

[@freelyroaming]

You're welcome! Thanks for your comment and thanks for watching the video.

[@gabe2045]

Been waiting for a video like this for a long time. Awesome job on the video!

[@freelyroaming]

Thanks. Sorry it took so long!

[@MaximC]

Thanks for the tutorial and recommendations. Good to know.

[@sbabcock71]

I am going to get this ordered up so that I can build out my own battery system for our camper.

[@freelyroaming]

That's exactly what I use it for. It has been great so far.

[@sbabcock71]

@@freelyroaming Outstanding!!!

[@tylersathern1076]

Excellent. I like your posts.

[@energiasolaroff-grid3544]

Congratulations my friend the best battery for lifepo4, it's a big Peck.

[@jedics1]

I have been using similar batteries to these as almost my only source of power for nearly 4 years now, all done from youtube videos like this and zero experience. The price to performance has improved so quickly in that time, roughly 40% more capacity for the same size and weight for less money is incredible.

[@OmahaWayne]

Just found this video and this channel. GREAT JOB, thank you !!!! Liked and subbed

[@freelyroaming]

Thanks!

[@bbanditrat]

Thanks , very educational for beginners. Very good video compared to others out there. You stressed safety which is very important but safety glasses and at least sunglasses should be worn at all time working on battery like you did. No metal when welding or electrical work period.

[@happyhour6097]

nice point on the length of the wires thanks!

[@aday1637]

These batts will probably be lower in price over time. The other facet not mentioned in this video is the ability to add more cells either in series or parallel. Either changing the bms or adding another depends on how you wire. But these are a great starter with budget in mind which can be increased over time without tossing any you've already purchased. 16 in series give you a 48 nominal volt setup which requires smaller wiring for the same watts used. The versatility is just wonderful.

[@jimh8478]

people should not be afraid to try this, I really appreciate those who will encourage diy crafting. Some of the direct replacement options are total crap and unless you are willing to cut them open and see what is inside you have no idea what you have bought.

[@freelyroaming]

If you are not afraid you should try. If you are, you should not. I've seen too many poorly constructed electrical project built into moving vehicle and enough fiery inferno as a result to think everyone should do it. There are more than enough budget yet high quality batteries out there. Just buy a name you recognize and you will be fine.

[@stefanmargraf7878]

Very good! Iuse strapping tape with glasfibers in it. In case of the cells getting hot, it wont fall apart.

[@freelyroaming]

That's why I used. Although it's really not likely to reach any temperature hot enough to cause the adhesive to fail when this is used in an low c rate environment.

[@SoundzAlive1]

Hi Dan, BTW The 280K is the 6,000 cycle battery from EVE as the 280 normal is 3 - 4,000 cycles. Best charging the batteries in parallel to connect the positive at one end and the negative at the other end of the battery bank. This will avoid the first cell in the line taking the most current and last one the least. If you get a chance to try the JK BMS it is the best on the market according to me and Off-Grid Garage on KZbin. André

[@freelyroaming]

What do you like about JK BMS? Active balancing? And you actually believe what Andy says over there from his broken shack down under?!?! Just kidding 😂 He's making some good content over there.

[@SoundzAlive1]

@@freelyroaming Yes the active balancing is the main difference. It is fully featured and seams to be very reliable. I was commited to package deal with a DeliGreencs BMS new parallel version so I could not change. André

[@offgridwanabe]

Life is easy with those big cells

[@mausie1967]

Thank you, I liked your video.

[@freelyroaming]

Thanks for watching!

[@brucebugbee6604]

Nice video. One item that you should consider doing is to connect the main negative load leads directly to the battery terminal, then attach the balance lead on top of the load leads. That way the load leads have better contact with the battery terminal and the lug for the balance lead is not carrying load current.

[@leonhardtkristensen4093]

But then it is not turning off if the voltage goes too low which is one of the main functions of the BMS. I would suggest not to do that.

[@freelyroaming]

He's talking about the stacking order of the ring terminals on the lug. It's not really that critical for off grid power use but for high current draw applications like EVs it might help. But even then it's not really gonna make any noticeable difference. Just best practices kinda thing.

[@leonhardtkristensen4093]

@@freelyroaming Ok that makes sense. I understood that he didn't want the load to through the BMS. Sorry.

[@hemibreath]

Very nice 👍 Helped me allot

[@mostrogolf22]

Hi, since Im taking a deep dive into renewable energy, I understand there is a cost saving in a DIY version of a battery vs buying a LiFePo4 battery. My question is the following, how big or small is the safety concern of a daily use of a system built DIY vs just buy a portable solar generator system with a battery bank integrated in the same compartment like the Bluetties and Jacakrys? I do like to tinker with stuff, and you made it look fairly easy to build that 280AH battery. That motivated me to think in building a system.

[@superformOG]

i just bought a 304ah with heating for 1700 euro, it just has a JBD bms and eve cells - i know this costs only about 5-600 euro so its was hard to swallow, but it helps a local guy out and i dont have to think about it, i think next time in 10 years or so I will build my own.

[@daleval2182]

If all goes normal world, a battery will be already built for 10c a watt

[@luctessier2215]

Very informative video. You mentioned at the begin about showing a 3rd temp sensor, was it mentioned or did I miss it?

[@RESTESSMYSTIC]

Great info.Thanks

[@2hotscottpro]

Nice vid !

[@cutty02]

bought 2000wh ac200p for $650. cant beat that on DIY.

[@rorymax8233]

Thank you, I am now convinced that I am going to do this, very much appreciated 👍👍👍

[@mikewaxx]

this was fascinating but i disagree about one thing, i would definitely put the BMS on top. Put it on the side and it's vulnerable to squishing or impacts, but on the top it's protected somewhat by the + and - terminals. And i would cut the sensor leads (and the ground leads) as necessary. Because the input impedance of those sensor inputs is quite high. That means that those leads are not pulling any real current and so cannot drop a measurable amount of voltage no matter how long they are. I noticed that in the menu settings the balance precision was set to 30mV. The voltage drop on those leads is much less than 1mV. Great work though, thanx for posting.

[@freelyroaming]

Thanks. There are lots of pros and cons to how to build a simple pack. Doing what makes sense to you is what is important. This is just meant to show the easiest, no frills build so that more people can understand how they come together. Thanks for watching.

[@DLong-wp8su]

Thanks for sharing the knowledge. As right now, you can buy Chins 300AH around $970. I don't see much of the saving because the cost of 4 cells 3.2v is $750 + $130 BMS + bluetooth.

[@freelyroaming]

If not a lot of savings you will have more features like low temp protection, Bluetooth connectivity, smaller footprint and most of all, ease of maintenance. This for me was less than 700 bucks all in. I don't know about you but that's more than 300 bucks cheaper than Chins using my math especially when factoring in tax.

[@dnlmachine4287]

@@freelyroaming Espcially if youre going 48/51 Volts, savings add up. Stay gold.

[@wg6215]

Correct me if I'm wrong but last time I checked, red was positive and black was negative. You appeared to have connected the blue bms negative leads to the positive terminal on the battery pack. Just an observation

[@lyndsaybeck2249]

I live in Canada. Any chance you could recommend a BMS with same features but also able to accommodate heat pads. Appreciate the tiem and effort you put into your videos.

[@GoGadgetsLife]

Lyndsay,Whats you battery details ,Maybe i can offer help

[@lyndsaybeck2249]

@@GoGadgetsLife SOK 100Ah 12V LiFePO4. I bought them 3-months before the same battery with the option of heater pads became available.

[@svendittmann3105]

@@lyndsaybeck2249 use an active balancer (aB) for your 100Ah cells. They have much more precisious performance then such types. You configure only the cutoff voltages (2,5Vmin / 3,65Vmax per cell) in your inverter. The balancer manage the cells until 0,001V difference. An aB produce no heat and your system has no powerl loss! negative: aB have no BT and Apps if you want present your cells your neighbour ....

[@bigdaadio.K2WW]

Thanks for the concise video... One comment: The cell sense wires of the bms CAN be cut, there is no way 20ga wire, at .01 ohms per foot at 3,2 volts, with virtually zero current draw, is going to have any voltage drop. I notice nearly all the DIY builders think the same way, which tells me they all watch each others channels. The instrument doesn't have close to the resolution to read any difference. Simple ohms law for voltage drop. It would be microvolts

[@freelyroaming]

Of course it can be cut practically speaking. But when you make a video showing people how to do things, you need to teach best practices. The best practice is to not shorten them. There might not be a measurable difference but there is a difference at least in microvolts.

[@philipardvall1968]

Nice video, Im thinking about building one myself and took contact with the reseller you linked, so did you have any problem with them and Cassie Wang there said it would cost 560$ with shipping and all to Europe. So you think that this is a good price or should I wait?

[@davidpatrick1813]

Could all the tape cause the batteries (cells) to not dissipate heat well enough? This was very enjoyable to watch and makes me want to make one (or more).

[@freelyroaming]

Perhaps. But so would an enclosure. For off-grid power, the c rate is very low so batteries don't heat up that much. It would actually be a benefit in cold temps. Like I said, there are lots of ways to build a battery. this is just a good and fast way to build one in about 10 minutes for a KZbin video.

[@Rob_65]

There are a few things you should take care of, apart from not assembling the battery on a steel table. Don't use an adjustable wrench to tighten the nuts - it.s too easy to accidentally creating a short circuit. Use a socket wrench instead. Don't use scissors to cut tie-raps but use short snips (with insulated handles) for the same reason. Do not tie-rap all balancing wires together, if there is any damage on the insulation of the wires you may get fire or at least smoke. Do not tie-rap the C- and B- wires in one bundle - if they short circuit you are disabling the complete BMS. Never ever use those large heavy cells wrapped in just packing tape. It's too easy to get a puncture in the wrapping or denting the cells. Also, follow the manufacturers specifications on how to mount these cells. I've seen manufacturers specifying that you must compress these cells to make sure they cannot bulge, resulting in de-lamination of the cell. How do you think these are EVE cells? EVE is a brand with a well known reputation so anyone selling EVE cells will leave the EVE label on the battery or at least have their own label with "Manufactured by EVE" on it.

[@freelyroaming]

You should watch some more of my videos before making your critiques. I've got plenty of real world and technical experience building off grid electrical systems. 'Not my first rodeo' is the common expression .There is plenty of other videos showing how I've built packs that I actually use. As I stated pretty clearly in the video, this was not meant to be a 'best practices' build video. It is just to show how components go together which was something requested by subscribers. And for a non-mobile setup, there is zero risk of insulation rubbing, chafing and shorting. As a full time traveler who does a lot of DIY projects, we don't have the luxury of a workshop full of tools. Learning to do with what you have is a very useful skill. It is all about understanding and assessing the risks and make it work with what you have. I assume you just landed here from KZbin recommendations without knowing other already posted contents my channel. There is one all about cell compression as it sounds like you might learn a few things from it.

[@cdoublejj]

i got an aliexpress 150Amp clone of that bms and a BT module for i think under $80 USD shipped, if not around $75, that was a year or two ago

[@bobl168]

Can you do a video on the Bluetooth connection. I am concern there are complication or it gets tricky to connect to it.

[@tommussington8330]

What about using coroplast corrugated plastic signs as your dividers for battery and bms that way they can get some air between them

[@freelyroaming]

The only problem is if you use something too thick the bus bars will probably not reach the studs.

[@earthenergyhex]

thanks bro!!

[@SamuelHollandsh]

Nice👍👍

[@sparrowsends]

Hi Dan, you spoke about balancing on the video at about 13m 53secs did you do a video on this after thanks in advance.

[@anthonyspeters7203]

Great information will help me greatly deal I'm goin to make battery pack to charge on off peak electric @ night to use during day giving me 24hr off peak lectricity shud save a great deal with big rise in energy prices, think l need to aim for sbout 10kw to run bungalow in day! Don't think l should have any problem putting that together, I'm a retired electronics tech! Just hope l can get all stuff you got shipped here to U.K. very good presentation lot good information thanks so much saves me time on researching all this myself!🤗🤩😎🌹

[@MacMcCabe2456]

I'd like to build a 36 volt 100 amp hour battery for my 36 volt ezgo golf cart. Any suggestions on components would be appreciated. Thank you, great videos !

[@kswis]

I am using a couple of those JBD bms's from radio tech. They haven't givin me one issue in yrs but the app can be frustrating

[@freelyroaming]

That's good to hear. The app is very powerful but not intuitive. I'm testing to make sure the data is accurate and reliable and the will take time

[@GHE2005]

That was great. I'm just starting to think about building a battery system. So the two temperature wire r for low & high temperature, right? Do u hv a video about discharging & charging the battery b4 u build the battery pack? I need to know what type of equipment is used to do that?

[@bobforte9343]

The most common charger is often a 30V 10A bench power supply that goes for $75 on Amazon. You could probably get a higher amperage charger for ONE specific voltage but that gives you no flexibility so I would really recommend getting a bench power supply. If you can afford something that can do 20A then I would recommend it just to save yourself some time. Discharging…first ask yourself, do you want to capacity test? For $50 you can get a DL24 load tester but it’s limited to discharging at a max of 150W or 20A. If you don’t want to capacity test then you could hook up a super basic DC load (bulb) or get some bigger power resistors and use ohms law to calculate a load small enough that won’t melt some 100W resistors but big enough that it won’t take centuries to drain it. You need a low voltage disconnect module

[@GHE2005]

@@bobforte9343Wow thank u for all that info. I'll do some more research about all that u noted. I'm a visual person so reading the info I don't get yet. But I truly hope ur explanations. 👍🏾😊

[@BobGarlington]

Hi: Thanks for this video. Can this cell pack and BMS times 3 power my golf cart, or is there to much inrush current for this BMS. No doubt the batteries can do the job, but how about the BMS.? Thanks. Bob

[@bonegunner958]

Thanks Great Video Why was cell #1 red and a B flashing in the bluetooth display?

[@freelyroaming]

It is showing the balancing of the cells. Red signifies which cell has the highest voltage and is being resistively drained to a lower level.

[@alexanderkrupnov4999]

Nice work! Why was BMS chosen for a maximum current of 120A? It's only 1.44 kW. Is this power enough? Your battery can give much more, at least 2 times. For example, 200A (power = 2.56 kW) or even 250 A (power = 3.2kW). What is the basis for choosing a BMS with a maximum current of 120A? Thanks for the answer!

[@ozmanfidaar6311]

Cost and application often determine BMS selection.

[@jasondevine6014]

Cut the wires, the BMS has next to no current when measuring so therefore no voltage droop. Also when top balancing no need to wait when first connected but when charging leave at 3.65 for a few hours.

[@freelyroaming]

I've explained this in several comments exactly like yours. You'd understand if you are someone who makes videos like these

[@bobl168]

Have you tested cold temp disconnect is working on this bms?

[@willpatrick8706]

I’m going thru the Freely Roaming Series. A though came up. Where are the Bodwells. Do they have a KZbin Chanel.

[@freelyroaming]

No they don't do KZbin. We actually just spent a day with them last week. they have been living in Colorado while their son goes to high school. He was out here on California visiting college campuses.

[@TinyHouseMike]

I found some 320a cells. I will be building a battery very soon. What amperage to you recommend for the bms? Is a 200a bms to much?

[@freelyroaming]

No it's not too much. It is all based on how much max current you plan on drawing from it.

[@mariusgheorghe7940]

Very well.i have one question :i have 4 cells of this kind batery :12v/320A .the BMS must be 320A or less?i do not understand.can i use bms 150A?thank you

[@saintcosmic4378]

Hello, I've seen a few of your awesome videos and am now hoping to get some advice. I'm new to the battery / car camping scene. I plan to keep an Amazon LiFePO4 battery (maybe 2) in my car as a power source for a Dometic fridge, lights, laptop, etc. so I can live in my car on the weekends. I'm still shopping / researching so I wonder if Group Type matters, mixing battery / inverter brands or things like that matter? I want to charge the batteries at work then bring it to my car and shelf in the cabin with me. So far it sounds like I'd need the battery, and an inverter. And I think I can just plug a power strip into the inverter? Do you see any issues or have any advice for this type of use?

[@JH-fk2lw]

With the BMS you used can you program the max charging amps? I am building one for my van and wanted to know if I can program the BMS to a max 40 AMP charge. I could use a DC/DC charger if needed but would be nice if I could do it without the DC/DC charger.

[@freelyroaming]

You can't exceed the hardware limits of the BMS so usually it is not programmable

[@johnzuro4596]

I did this set up with just the 120 amp bms. I have a 40 amp. Rich charge controller and two 200 watt. Panels. Also 3000 watt pure sine inverter. I have been all over the app and can't get my cells to charge past 13.4. I put my Noco genius 10 on it with the bms hooked up and I only get 13.4 and only 3 out of 4 red bars on the charger no matter how long I wait. When I charge the cells without the bms hooked up, I get 14.4. Then, as soon as I hook the bms up it takes it down to 13.4. I have calculated about 50% capacity. Maybe less. The only thing I can think of is the bms needs to be a 250amp? Advice would be perfect. Maybe parameters I need to change? Thanks

[@MacMcCabe2456]

I'd like to build a 36 volt for my EZGO golf cart. How many cells would I need to equal six 6 volt Trojan T-105's ? And, can it be done ? Great videos, enjoy watching......

[@mikek9488]

3.27 volts on the tester per cell

[@melaniecollins4045]

Hey Dan, do you have a video that shows what parameters to use on the mppt for our diy batteries? Or did you get them from the supplier?

[@freelyroaming]

If you use a victron charger then you can just use their built in lithium charging profile. In one of my older videos of the battery build I did show it. I can make a quick video to show parameters.

[@melaniecollins4045]

@@freelyroaming awesome thanks! I think a quick video would help a lot of us. 🙏

[@thanapatrachartburut513]

If you don't want large Ah , lead asic is still good enough for you compare to cost and lifespans of it.

[@igorkvachun3572]

Yes akb LiFePo4 🔋⚡👍

[@tribalncgaming1091]

200ah 12v lifep04 from redodo are 459. shipped and i even got a 30.00 amazon coupon so it was 429.00 kinda hard to beat, i am running a pair of them in series with my 3kw powmr all in one inverter for my camper.

[@freelyroaming]

200Ah Redodo doesn't have low temp cut off. For $469 you could have gotten a Golden Mate 200Ah that does like this diy kit. Running 2 of them takes up 3 times the space for someone with a smaller camper.

[@tribalncgaming1091]

@@freelyroaming I had already watched a review on the redodo 200ah .. and understood that it had only a high temp cutoff. i am running a 18w warmer with auto thermostat it will cut on at 50'f and cutoff at 70'f (made for a chicken coop) since i am setting up inside a externally accessible storage area .. it looks to be the ideal answer to keep the batteries warm.

[@2hotscottpro]

How many of those bats would be needed to run an RV 15,000 btu AC? So one said I’d need 7 or 8 400 watt panels on the roof.I think I can mount 7 on my roof but not 8.

[@philipardvall1968]

@freelyroaming did you have any problem with the cellar supplier?

[@crowdiver]

I hooked my daly sensing wires to the positive terminals is this a different set up or does it not matter ?

[@brianmosher4053]

So for an application such as car audio that has high current draw what BMS should I use?

[@researchandbuild1751]

How does the battery charge on negative? You leave the negative bms wires "hanging?". Huh, interesting. I would have thought you would be connecting loads directly to the battery but i guess if the bms has protections it hzs have to have the current go through it

[@freelyroaming]

That's correct. If you connect directly to battery negative, it would work of course but you would lose all of the protections of the BMS. Because this is a common port BMS, it means it charges and discharges from the same negative port. The protection schemes apply to both charging and discharging so you never want to connect anything directly to the raw negative battery post besides the BMS.

[@researchandbuild1751]

@@freelyroaming That makes sense now. Thanks a lot for making this video! It looks pretty straightforward to build this. That's a huge battery ! 4Kw of energy for only $700ish, wow

[@thomasgriffin4714]

What torque did you use on the terminal nuts? Perhaps I just missed it.

[@freelyroaming]

Didn't specify a torque spec. I am using a lock washer instead of the serrated flange nuts. I just get it down to snug and give it another 8th turn. Usually enough to hold.

[@pr5991]

Does this bus do active or passive balancing?

[@MidAtlanticTV]

Do you have another BMS you recommend? The one you mentioned is no longer available on amazon.

[@freelyroaming]

This is their latest option amzn.to/3RZef9B

[@MidAtlanticTV]

@@freelyroaming Thank you!

[@marvgan]

Is there a relation between the bms Amp power and battery Amp Capacity? Do these both must have the same Amp rating? Or its ok for example to make 4 series 60Ah lifep04 battery with a 20A bms?

[@freelyroaming]

No they don't need to match. The output amp rating is the highest amount of power you think you might draw. Higher amp rating will need a bigger and generally more expensive BMS. You can also run multiple BMS in parallel if you choose. Just make sure it you don't draw more current from the battery than it's capable to.

[@MacMcCabe2456]

I'd like to build a 36 Volt package for a ezgo golf cart.

[@teemum.9023]

nice

[@gregboyd4321]

So should one charge up the battery one cell at a time or change all 4 once it is built? Charger type?

[@freelyroaming]

All 4 at a time. If you are trying to top balance, connect them in parallel and charge to 3.65v. if you are just charging them as you normally would during regular use, build the battery with the BMS and charge to 14.4-14.6 or whenever the BMS cuts you off. You need different chargers depending on what you are doing. A typical 4S LiFePO4 charger will not work for top balancing. This is a topic for a standalone video.

[@agritech802]

Thanks for a nice tutorial, what is the advantage of this battery over a 12V 680Amp 110Ah lead acid battery costing $200, is the lead acid battery working out cheaper per Ah at that rate?

[@bigdaadio.K2WW]

well 110ah lead acid, compared to 280 lifepo4/for one thing. So basically you need 3 so there's $600 His LifePo4 battery can be run to near EMPTY, do that to a lead acid a dozen times it will be scrap. Lead acid shouldn't be discharged more than 50%-60%... if you expect any kind of longevity. So NOW you really only have a 50ah battery. NOW you need nearly 6. Hows the math going ? 6x$200? which would you prefer?

[@freelyroaming]

And it will be about 4x the weight. Which comes to around 200 lbs worth of lead acid. For an equivalent LiFePO4 pack comes in at closer to 50 lbs.

[@agritech802]

Ok thanks for the clarification 👍

[@matb5368]

Cos you can only use 55ah of it without damaging it

[@choochootransportservices2248]

I don't know if it was ask can you use these for car audio

[@jimurrata6785]

Is there a reason you use three lugs on the BMS negative lead and bunch them all together on one stud, instead of crimping all three into one larger lug? It seems to me (ignorant) that it would eliminate a bit of the 'spider' and not have a huge stack of lugs on the battery stud?

[@freelyroaming]

Small wires crimped into large lugs have a tendency to slip out. Also it complicates the build as it requires you to undo the already-crimped sensing wires without adding much of a benefit as you will still have bundles of wires to manage.

[@jimurrata6785]

@@freelyroaming Thanks for the reply! You really break it down for your audience. I'm unsure what the three thick current passing wires have to do with the thin sensing wires? 🤔 But I do see why they are using three silicone insulated wires to make the connection to the board more compliant. Great tutorial! Happy Trails

[@freelyroaming]

@@jimurrata6785 ah yes I see what you mean. The 3 wires from the BMS. It's just how the manufacturer have chosen to build them. 3 thinner, more flexible wires instead of 1 thicker one. Using 3 lugs also give you a bit more flexibility during the build process but a single large one could have worked but it would be slightly more restricting with regard to their angles of attachment.

[@coconutcrab4martin]

Experiencing pain, seeing a bright yellowish-white flash of light and smelling my burned skin helps remind me to wear gloves from now on. 13V is enough to travel through a slightly sweaty skin surface. God saved me again. Aloe Vera gel is the best of God's creation to cure burns.

[@freelyroaming]

Seriously? You can literally grab both terminals with your bare hands and nothing will happen.

[@Soleimpala77754]

im building a pack myself for workdue to supply issue what does the 120amp rating on the bms stand for is that the most amps it can handle? if so how would i go about making a pack that can handle 800amps. this is for a mobile hydraulic stage

[@freelyroaming]

You can connect multiple BMSs in parallel.

[@daleval2182]

You where touching all reds in one hand at the last steps of add. bms. Is that advisable?

[@freelyroaming]

Are you talking about 19:25? If so, it's not a problem. All 3 of those wires are combined into the main negative of the pack. There are just split into 3 conductors to be more flexible while still able to carry a full 120A load.

[@restfulplace3273]

I know a lot of these bms have Bluetooth, I’m thinking wifi connection for remote monitoring and data logging is highly desirable. Are there other bms with wifi connection or a Bluetooth - wifi bridge to log the data??

[@melbournesubtropicfruits9474]

I have a tight build width - whats tbe widt6of these 280ah cells in mm? - thanks

[@djkillachris]

I already have 2 100ah from ampere time. Can I use those with one of these in one bank?

[@freelyroaming]

Ideally no. You are better off getting more of the same batteries.

[@siov4279]

Why not insulate behind the bms? maybe install it on a wood half inch block? or even some sort of a heat synk

[@freelyroaming]

There are a lot of things you can do. See my other build videos for those. This is meant to be the easiest way to put a pack together.

[@LifeWithoutOffice]

Can I use smaller BMS than cell nominal AH? For example, I got a 4x280Ah cell and use only 120Ah BMS? Is that secure? Can I use an even smaller 60Ah BMS?

[@freelyroaming]

Yes. It doesn't need to match. Just don't go too much over the rated output current which is usually 1C. That would be 280A in this pack.

[@reamtm1]

i gone a do 2 pack of 8s in series to make 2 pack of 24v and 320ah and them connect in the 2 pack in paralel and made 24v 640ah the question is to do that whith one bms whith 16s cell. the question is can di that 2 pack of 24v in series to them connect in paralel to make 24v 640ah which one 16s bms or not

[@section954]

What if a person just bought the celss and connected them without the bms. Would they work and be ok to charge?

[@freelyroaming]

You could over charge or discharge cells which will permanently damage them.

[@dontaskmeforusername]

It's more dangerous to get into a car and drive down town, but I've never had a disclaimer about that. Lol

[@freelyroaming]

First time for everything

[@siov4279]

so in order to buy from alibaba there are stipulations are there not?