7 Steps On How to build The Safest DIY Li-ion Battery

[@Zinxen92]

1. Know the maximum draw of your motor 2. Match the current output of your batteries to the motor 3. Ensure bus bars can handle the current 4. Create space between cells to allow cooling and avoid short circuits 5. Know the maximum output of your fuses (Use a fuse from cell to bus) 6. Isolate the entire pack from exterior elements and causes of short circuits 7. Temperature control and insulate the battery pack thermal threars

[@Jetsonn]

Is there really any cooling that goes on with a pack between the cells or whatnot when it’s wrapped in tape and heat shrink and foam and insulation material inside a closed plastic or metal case? It’s not like the open air of you cruising down the street is passing over the cells and dissipating heat 😂 I don’t think the spacing of your cells matters unless you’re going around poking holes around your battery case or have a fan or some sort of heat-dissipating material or something

[@diogocoelho496]

@@Jetsonnis more in case of short circuit the metal shell outside the cell is the negative and the plastic is very fragile

[@snorttroll4379]

threars?

[@blise518B]

The theory in the video is good but it just does not explain what a DIY hobbyists should do. You said to not solder the fuses but unless you have one of those machines you can’t really do it in another way. For small packs it’s okay to not have cell level fusing and just spotweld the pack without fuses. The fuses add additional resistance to your pack and make it a bit more fragile.

[@creeperproof2]

amen

[@glasslinger]

Just keep in mind that it can burst into flames at ANY time from a defective cell or dendrite formation.

[@blise518B]

@@glasslinger if its an internal cell problem no fuse will save you anyway... when one burns the others go als well.

[@glasslinger]

@@blise518B Oh shit! I guess I will stick with alkaline batteries and throw them away every week! :)

[@ElectricVehicleSpace]

@@blise518B the fuses will! It's shown in the video how it works and it's explained!

[@Lucid_Waking]

Thank you for making this video. I think you've saved people from potential injury. Cheers

[@sasanito3169]

6:55 I could watch this all day

[@GENcELL2014]

There'll be a revolution in battery assembly fairly soon. Cylindrical contacts that fit into drilled holes in a sheet is the easiest straight forward way. Cylindrical contacts are basically insulated cables or wires engineered into being electrical contacts. I've been working with a company in the US to bring their contacts to the battery space. Their contacts are originally used for pcb testing in industry. Custom cylindrical contacts can have enough conductors to reach currents as high as 60A. Imagine battery construction like this, 1. Place cells all in the same orientation(positive side up) into a cell holder. 2. Place sheet with Cylindrical contacts which has cell holder features bellow it for alignment and a pcb(pcb can have built in fusing) or foil above the sheet with contacts. Cell holder, sheet with cylindrical contacts, and pcb/foil can all be joined together(bolts or laminating meaning adhesive) becoming one assembly. 3. Screw down assembly with a cover and batteries built with all connections to bms already made. No fancy robot or time consuming welding process needed. Similar cylindrical contacts making contact to cells can also make contact between batteries final pos and negative aswell as voltage sense to a bms within batteries cover. No wires or ribbon cable coming from battery except pos and neg out of bms and something like a couple wires for communicating with an inverter or the like. SSA or single sided assembly, negative connection is made to cells rim on positive side. Allows for one cell holder, contact sheet, and pcb assembly per battery instead of two like with DSA or double sided assembly. DSA is good for high current builds but SSA can also be quite high current just not as easily. Also the cylindrical contacts within a sheet will be many times cheaper and smaller footprint than contacts like leafsprings and aren't soldered to pcb.

[@waverley41]

what's the company called?

[@GENcELL2014]

@@waverley41 HCD Inc (High Connection Density Inc) makes this style of contacts.

[@soutasiantraveller6493]

great idea 💡, this can save thousands of batteries whose lives are reduced by soldering and other things

[@MrSup911]

@@GENcELL2014 Any updates on your efforts towards making this system a reality? Sounds like a great step forward!

[@GENcELL2014]

@@MrSup911 yeah at this point it's been refined from a sheet with contacts to fairly small contact carriers(one variation for positive and another for negative on cells rim) which'll be mass produced and then populated by HCD cylindrical contacts to achieve very low cost contacts and accommodate many variations of series and parallel connection batteries more easily. Contact carriers are sandwiched between cell holder, pcb or metal sheets and a rigidity sheet or pcb cover with bolts holding everything together. Contact carriers are geometrically held in place with simple geometry in cell holder instead of double sided adhesive sticking them to pcb. Not using adhesive simplifies and lowers contact cost by avoiding having to order and manage custom shaped adhesive that needs to be accurately applied to a fairly small contact carrier.

[@Piko_project]

can i ask you recomendation gloves when build battery pack?

[@ElectricVehicleSpace]

Good idea to use gloves 👌 but that for high voltage. I only worked on max 12S packs. It's not really needed in my case.

[@japrogramer]

What is the machine that is connecting the batteries with the tiny wire at the end?

[@pauls5745]

spot welder

[@bobdebouwer7835]

At 3:07 point nr 1. Isn't it the controller that decides how much current will go to the motor? So shouldn't we look at what the controller demands instead of the motor specs? Just trying to learn here.

[@naambacchus]

Thanks for your info

[@tomlogan2102]

What a great video. Thanks tons for the info.

[@ElectricVehicleSpace]

Glad it was helpful! Please share and like!

[@BobboNaught-YT]

So many great points. I can't believe people hot glue their batteries together for ebikes that are going to vibrate down the road, it's an absolute recipe for disaster.

[@repinscorpio]

Could please you make a detailed guide on how to make it right?

[@ElectricVehicleSpace]

i just did

[@JamesBiggar]

@@ElectricVehicleSpace Nope. You didn't. This is a classic "they did it wrong but I do it right and I'll show you" video that slams actual builders to piggy back on their success but doesn't show better alternative BUILDING methods - it's just a quick, vague overview of common sense principles that should be considered in the PREPARATION of the build. ​If anything, this video just added to the confusion for the layman. Exhibit A: you say don't solder the cells, then proceed to show a clip of fuse wire soldered between the cells and say that builders need to do this but you provide no alternative to soldering. How do you 'fuse' fuse wire to the cell without soldering? Should have mentioned nickel fuse strips that can be spot welded instead. That would be a good start on the road to providing detailed information.

[@ElectricVehicleSpace]

@@JamesBiggar I shown the pack with fuses that was spot welded.

[@ElectricVehicleSpace]

@@JamesBiggar I am going to review in a week or so I cool portable spot welder and I will show again best way to do it. I did test these fuses and they worked and save the battery and the board from catching on fire. I have not build motorcycle batteries but it should be the same principle. I hope I do build an ebike soon if I find a place to weld.

[@MrSummitville]

@@ElectricVehicleSpace What is the amperage rating of the Fuse Wire that you used between the cell and th ebus bar ?

[@spyterpig]

so for number five you choose a size of wire that melts at its highest cell discharge rate? is there anyone that sells different amp rated wires so i dont have to salvage from wires? also how do you put that fuse on the cell without soldering or can you do it with a battery spot welder?

[@snorttroll4379]

I store my cells in my bedroom. over my bed. in a cardborard box. no electrodes toucing. any tips? can I store them outside in minus 25 C? I want to make a safe system.

[@ElectricVehicleSpace]

Best battery storing location.

[@snorttroll4379]

At least that way one can keep track of them@@ElectricVehicleSpace

[@glasslinger]

Outstanding video! So many "cheap" no-name commercial batteries DO NOT follow much of this advice! Take a shortcut and burn your house down?

[@energieundhobby]

Very great video, thanks for that 👍👍

[@ElectricVehicleSpace]

Thank you! 😊

[@charlescarleton3091]

Was curious about that large water cooled motor at minute 3:10. Could you tell me the name of the motor/supplier? Thanks

[@ElectricVehicleSpace]

there is no scooter at 3:10 time frame

[@johnjones6544]

Hey great video do you know where I can get these fuses wire

[@ElectricVehicleSpace]

Thanks I made them

[@MisterJohnny03]

what kind of bus bar should i use for a 10s10p battery

[@ElectricVehicleSpace]

depending what set up will it be used for and the required draw for the all system.

[@MisterJohnny03]

@@ElectricVehicleSpace i need it for a 1kW motor that draws 40A continuous

[@Jason2003]

you talked me out of modifying a battery pack I have. Probably for the best. Thanks!

[@andreyeampierre2377]

4:30 Whoa... so there is no need for trial and error projects, huh? The fuses follow the same principle of amp vs capacity

[@JackButlerVideos]

I saw a snip of my video in there. Would have been nice if you asked before using it but that's up to you. I agree cell level fusing has it's place but I think it could do more harm than good with DIY builders who can't achieve the same precision as on an industrial level. Your basically filling your battery with a bunch of resistors that will create more heat on top of what the battery is producing normally.

[@invictusfarmer7188]

that fuse machine is amazing

[@andreyeampierre2377]

3:35 Okay so the type material and size of material holding the current is directly associated with the amount of energy passing through it... 🤔

[@Seneslau07]

Do you consider problematic if receiving new li ion cells at 3.44v? I've received my new 21700 Samsung INR 40T3 4.000mA, 35A cells with 3.44v. Is that too low? I've builded an 2.8 kw 24s8p battery for an electric paramotor and has a huge voltage drop at 10-17kw full throttle and it should handle it like other similar batteries. I'm trying to find out why. Thanks.

[@henrikgure2123]

No, it should be fine just the capacity may not be 100% more like 80%.

[@Seneslau07]

@@henrikgure2123 Hmm, interesting point. Other battery builders told me they also received cells at this voltage and it is normal. But your ideea might explain the voltage drop at high loads..

[@imho7250]

The new laws pertaining to shipping lithium ion batteries requires the SOC not exceed 30%, thats why you no longer see cells arriving at 3.7v like before. As far as voltage sag, just look at the average sag reported by your Bluetooth BMS, and the amps, divided by your cells in parallel, then find the manufacturer’s datasheet or a test from Mooch, and see of your cell sag is following what’s expected. 17kw is about 25a per cell in 24s8p and thats the realistic CDR of the 40T, and it will sag from 4.2v down to 3.7v in a few seconds. Of course proper battery construction is also important. Especially giving each P cell its dedicated current capacity to the next series. There are some batteries only giving 4mm^2 for 450a series connections.

[@Seneslau07]

@@imho7250 Thanks a lot for enlighten me! Someone even asked me where I bought the cells so he can avoid! Others said is ok and they received the same. I'm on my 5th flight and I love it. The 2.8kwh batt gives me 26min flight time and I land with 43% left, 1.8-2kwh drained from the 2.8kwh batt so I could go a little more. I have no bms, have temp senzors, voltage alarms etc. Level flight is at 3.8kw load, climbing at 5-6kw and take off at 7-8kw so no need for more than that. I even mounted a thermo probe on the pure nikell strip that's on parallel connections thinking maybe it gets hot but it has same temp as the cells. They go to 43C at the end of flight which is fine. I've posted about this on the Endless sphere forum endless-sphere.com/sphere/threads/help-in-identifying-voltage-drop-overheating-reason.121079/

[@MrPamber]

Really informative and useful video. Though now I know what not to do, how am I supposed to do it?

[@ElectricVehicleSpace]

testing the spot welder soon and you will see there.

[@lithiumalan776]

Hi, Patrick, i can provide bms and holder etc.. if you want it , please contact me .thanks

[@Therealnaphtali]

bro killer video very informal thanks for taking the time to create this.

[@ElectricVehicleSpace]

My pleasure. Also take a look at the lucid video about their modules and how they implemented the safety fuses.

[@mo.Travelin2]

appropriate cell level wire for 2170 packs? best method to put those into a bus size vehicle EV conversion?

[@daviddelatorreperez4]

El problema no siempre es la batería, el problema también es o puede ser causado por los mosfet, todo controlador brushless estan conectados en paralelo los mosfet y el capacitor, que pasa cuando un mosfet se pone en corto? Pues va directamente a la batería y más cuando el fusible no adaptado a quemarse a un corto circuito, deberían de poner en serie un diodo en el + por si hay un corto, así ya no va directamente a la batería el corto circuito.

[@daviddelatorreperez4]

Saludos desde la ciudad de México 👍🇲🇽

[@deananderson3883]

I'm doing a tiny house project and would a battery that can be charged by solar panels. How much would it cost to have you build a battery for me that can support 2x PlayStation 4s , 2x small TVs and an air conditioner.

[@ke-kd8ut]

3k

[@carlosgarcialopez6402]

That's good theory on how to build safe Li-ion batteries, the problem is when you buy commercial products like laptops or e-bikes/scooters with batteries that clearly don't follow those steps.

[@dhanankh145]

many thanks for info 👍👍👍

[@jdedad]

Can you fix my battery pack it had a couple bad cells

[@Bergwacht]

Hey! does anyone know if I can actually connect a 12S battery pack with a 13S battery pack in parallel? I think the BMS of the 12S stops loading when it is full while the 13s will still charge up. And when I've run the 13s empty enough, the Bms from the 12s starts up again and both batteries discharge, right? Sounds like it could work, or am I wrong somewhere?

[@DKSanX]

I know Im mad late but if memory serves correctly if they are in the same arrangement ie Xs then you can just go and add them in parallel but you cant if they are not. The reason being is that each pack is a different voltage. When wiring anything in parallel they must be the same voltage and can hold and discharge the same amount of energy. If you wanted to make them equal you would have to add another set of batteries in series to the 12s and then get a bms that can handle a 25s pack. You could in theory run the packs with a bms but you would need to monitor both the charge rate and full charge of each cell along with the pack and make sure to never run the batteries out fully. Tldr no you cant but with a little tool work you can but youll need a new bms. Just remember batteries in parallel dont drain one after another they drain at the same time its just adding more cells adds to the reservoir it can drain from.

[@pianojacq]

Great info. How do you look at commercial packs manufactured by the ebike manufacturers and their suppliers (such as Bosch) that do not use individually fused cells but instead connect them in parallel using thicker strips and have a single overcurrent protection circuit on the BMS?

[@ElectricVehicleSpace]

Can fail easily and not safe. A opened a super 73 ebike battery and it had fuses so its happening

[@pianojacq]

@@ElectricVehicleSpace Interesting. Even the latest models Bosch packs (the 'Powertubes') are not fused. Do you have pictures of that arrangement in that pack?

[@pianojacq]

@@ElectricVehicleSpace By the way: these fuses are not there to protect against discharge currents, they are there for when the cell is internally shorted out to prevent the *other* cells from dumping their charge into the one that is already failing. This may prevent a fire. Typically this is used in vehicles against a pack getting crushed or damaged during an accident and the rest of the pack instantly dumping all of their charge into the cells that have been damaged causing them to explode. I think this is a fundamental piece of information that you were missing when making this video, or, if you did understand that it doesn't come out in a way that explains it clearly. So we are definitely not protecting against overcurrent discharge with these fuses.

[@ElectricVehicleSpace]

@@pianojacq that was the all point of the video and it is explained 👌

[@ElectricVehicleSpace]

@@pianojacq also overcharging or overloading or shorting.

[@jasenprice3164]

I'm building a 13s 12p battery and I need some help

[@ikechukwucollins8028]

Thanks for the video. Where can i buy this kind of battery

[@ericornhag1615]

Google 18650 litium battery 3,7 v

[@lithiumalan776]

Hi, we can supplier

[@hussalojr5916]

I was thinking about making a battery pack specifically for powering a computer away from the house, do you think I could use this to get away with that (I'll need a few extra pieces to control the voltage and amperage as well but as far as the battery goes what do you think)

[@TheExplosiveGuy]

As long as you have a current limiting circuit and can output a constant voltage as the pack drains it should be fine, I don't see why it wouldn't work. As long as it doesn't go over the operating voltage (usually 20 Volts with a 5% safety margin, which means don't exceed 19 Volts) and is current limited it should be fine. Make sure to include a low voltage shutoff circuit so you don't go below the cells minimum voltage or you'll scrap the batteries.

[@hussalojr5916]

@@TheExplosiveGuy Thx man

[@charlesthomas8375]

@@hussalojr5916 Thats pretty much what a laptop is, Go for it

[@GarrettRC5thscaler]

Excellent video but will BMS's make a difference in preventing thermal run off or no?

[@ElectricVehicleSpace]

The bms does not prevent that but fuses will.

[@GarrettRC5thscaler]

@@ElectricVehicleSpace Thank you

[@rickybobbyracing9106]

@@ElectricVehicleSpace fuses? On the BMS? Or do you have a any links to how fuses and be used to prevent this? I'm just getting into them and i want to be safe.

[@elomoto1993]

May you take similar approach to BMSs topic as in this video? The cheapest one are only resistive and that is just loss of energy and I'm wondering how does tesla do the balancing for example - I'm sure not the resistive way. Cheers

[@ElectricVehicleSpace]

There is a lot of info to discuss about the bms. I already removed 2 comments that are not related and the other guy is talking about using tape etc... things that should not be used and people don't understand the basics. I thick BMS is more complex and will confuse people than help. If someone decide still to make DIY packs they should invest more time to and learn all aspects of how to choose the right bms and how to properly use it. There are so many bad quality bms no on the market. You need to know which and where to buy it from.

[@elomoto1993]

@@ElectricVehicleSpace that's what I ment writing the previous comment. There is plenty of tutorials and vids about the cheapest BMSs. What is more most of them gives incorrect info that can't be trusted. To be honest after pretty darn good research I'm still not sure how the tesla or any other battery pack made out of modules connected in series should be balanced

[@pianojacq]

@@elomoto1993 You can use passive balancers using resistors to burn off the energy in the batteries that reach the maximum voltage (typically 4.2V) first, or you can use an active balancer which uses a charge pump to move the energy from those cells to the 'laggards'. Over a typical charge/discharge cycle you'll see that the difference between the highest and the lowest voltage groups in a string will be a few mV at best unless there is a serious problem. But over time those little differences accumulates and that is why you have to keep a pack balanced, if you don't you risk deep discharging and overcharging of the weakest cell group, and possibly even having it go negative. This is a serious danger, hence the need for a proper BMS, which senses the voltages of each cell group to mV accuracy and corrects where necessary. Cheap BMSs will simply shut off the charging when one group reaches 4.2V, and during discharge the other way, either 3.0, 2.8 or even 2.5V is reached they will halt further discharge. More advanced BMSs will work behind the scenes to keep the batteries balanced to avoid that situation leading to a longer pack life, and much lower risk of battery damage or worse.

[@nerk234]

.. From Italy...great intro... 👍

[@ElectricVehicleSpace]

Thanks! 😃

[@nameno544]

@@ElectricVehicleSpace can you safely run lithium ion batteries in parallel if the batteries are the same?

[@pianojacq]

@@nameno544 Yes, and even when they are not the same, provided that they are at the same voltage when you join them and that all of your series blocks are the same total capacity give or take a few %.

[@nameno544]

@@pianojacq thanks

[@its_arvinsingh]

The video isn’t clear enough, It’s understandable but the edit is very choppy. But overall, it is defiantly informative

[@ElectricVehicleSpace]

it tells you what not to do when building a battery. Now if you are referring to a configuration of a battery, that is a different story.

[@kartunenetwork9232]

Dont forget to use BMS, and always a plus to have a load balancer, my cells stay super healthy and balanced :)

[@ElectricVehicleSpace]

new video about batteries coming stay tunned.

[@snorttroll4379]

are there bms's that allow us to balance each individual cell rather than each parallell group? or is every cell in parallell balancing itself?@@ElectricVehicleSpace

[@Zues_1401]

Awsomeeee information

[@ElectricVehicleSpace]

Thanks ✌️

[@fantasminha.camarada]

Excelent video!

[@perrymickle]

sodering cells is fine. listen to this i did a test on a brand new 1500 mah " samsung" but it wasa chinese fake i think. anyways i decided to find out how damaged cells would get whe heated to just below thermalk runaway, multiple times. I used a blowtorch a held it on both the positive and negative ends of the cell, then out it back into the tester. AFTER DOING THIS 7 times witha blowtorch the results were that the mr increase by 10 and the capacity ddecrease by 50, basically nothing, even with a blowtorch I didnt damage the cells. But I have experienced thermkal runaway 4 times now and I know hoew scary it is but unless you pass that threshold heat does NOT damage the cells

[@ElectricVehicleSpace]

You are just lucky. Don't play the rullete game...

[@k.o.t.o.n.]

hy where are you located? could you build me a 150- 300kwh boat battery pack? for a 12kw engine. i have to stay under 3.5 tonnes everything included, but for transfer i could swap out the motor, clothes some movable stuff, liqueds and even the battery if possible :)

[@metatechnologist]

So I want to build a battery pack for a camper. It will see extreme temperatures. My first thought is I need to climate control the batteries. Very little is mentioned about this anywhere. Another thought is that I want it repairable. Something that battery packs wrapped really tight are not. Thirdly, I want the system to be self diagnostic. Not something that is common with battery packs let alone with DIY builds. Sadly it looks like I will need to engineer my own solution. Thanks for the video.

[@pianojacq]

For a camper I would look at Yinlong Lithium Titanate Oxide batteries. Not cheap but a really nice set of properties, as well as very high mechanical stability.

[@Johnny53kgb-nsa]

Very interesting. I know nothing about batteries, but it seems the battery industry, and the raw materials used to build them, is going to grow even more with the auto industries push for electric vehicles. Which I suppose is good, but what about the environmental impact of mining for the raw materials, and the human toll?

[@NakedSageAstrology]

After dying from my apartment exploding from my DIY battery, I would highly recommend You listen to these warnings & be safe!

[@sailingavocet]

absolutely~

[@2010stoof]

What seems like an explosion is actually thermal runoof all at the same time. Think of anytime you've seen thermite or lithium metal in water. Its not an explosion yet once they get together it becomes an explosion

[@TheNone724]

Someone should make diy wire bonding machine for cells that didn't cost much

[@gaetanopalaia2435]

Avendo un po di batterie 18650 da 3.7v E volendo costruire un pacco batteria per un scooter elettrico La batteria che monta lo scooter E di 60v 20ah Come li devo montare..... Quanto batterie mi servono e con quale schema montarle E poi o trovato un controllerxhe protegge 60v e 35ah i rete Va bene Grazie dell'aiuto.

[@caseydeveney6097]

Thx!!

[@MrDjdon87]

Assuming that the poles won't contact the opposite is the first reason that causes short circuit Most battery explosion happen due to dangerous design flaws I've been using li-cells for a decade for many applications but never had a single short circuit incident

[@angelme5692]

Spacers. Not absolutely required... And not possible to use on every scenario. (try to build a pack for a Laotie Ti30, the original battery doesn't have any spacers). Fuses. That's why BMSs exist... Surely a fuse is much much safer, but putting fuse wire on every connection is unrealistic, especially if you don't have a awesome spot reder... Tesla is a battery factory, don't expect DIYers to do the same kind of a good job without the necessary tools... Hot glue is fine :) As long as the pack doesn't get oo warm, it's perfectly fine...

[@Helpsmallbusinesses]

They need to make the solid state batteries because they don't catch fire when they are punctured.

[@BrieoRobino]

You say that like its that simple.

[@Helpsmallbusinesses]

@@BrieoRobino I didn't mean to make it sound simple. If it's not happening there's a reason that I don't understand.

[@pianojacq]

There is a lot of work done in this field. LiFePO4 is the main contender, but the density isn't quite there yet.

[@bodavis3819]

Seems like it should be common sense, but since it's not... Great video!

[@ElectricVehicleSpace]

thank you. i hope it helps.

[@MrSummitville]

@Bo Davis - Since when is Electrical Engineering called "Common Sense" ? Cell Level Fusing does *NOT* guarantee the a P-Pack will never catch on fire ...

[@bodavis3819]

@@MrSummitville wearing your seatbelt does NOT guarantee that you won't die in a car accident either, so I guess I'm missing your point. Also, if "electrical engineering" is such a concern maybe there are other avenues to take in being educated than KZbin. I was mostly just being facetious in my comment, but I guess that wasn't common sense either.

[@MrSummitville]

@@bodavis3819 Cell-level fusing does not prevent a fire, so then what does cell-level fusing do? Can cell-level fusing actually become a false sense of security = dangerous ?

[@racerx2095]

The thing is we all want more speed and range so I expect to see more videos of battery fires.💯

[@ElectricVehicleSpace]

if people continue to build them incorrectly than yes...unfortunately

[@racerx2095]

@@ElectricVehicleSpace 💯

[@JustNel]

@@ElectricVehicleSpace I am in the process of buying an eScooter and was looking at packs to extend the range.. do you have any specific packs you can recommend or what i need to look out for? Thanks

[@ArdiansyahRans]

the safety concern is good and all, but most of the time for e-bike battery builder, they use copper-nickel sandwich to deliver the outmost current from the battery, and using cell level fuse in this build almost impossible and easily make the budget multiply many times over. diy powerwall user that use old laptop cell most of the time, while most of them use cell level fuse, but they solder it anyway, because the price of proper spot welder that around $200 or more like glitter 801D just doesn't make any sense compared to the pack price that usually not that far from that price or even they got the battery for free, yeah solder is bad but if you knew what you do and how to do it, especially for powerwall, i think it's still doable. diy powerwall that goes kaboom most of the time is from heat generated while being used, not while it's made, yes it's survivor bias but the reality is like that, most of the time because of overvoltage because the solar charge controller they used are cheap one, and diy powerwall rarely pushed the current rating, they use less than 0,5C most of the time.

[@ElectricVehicleSpace]

Tesla is using a new tech now without fuses.

[@ArdiansyahRans]

​@@ElectricVehicleSpace i definetely need to read that, tesla is still ahead of it's time when it's comes to battery, chinese just behind a bit though, but as customer, competition is always good to push the dev. new technology is good and all, but on customer level, be it professional builder or diy level in my place, we need maybe few years or more to get a hand on that technology, that's why any prebuild branded powerwall or battery pack isn't realistic to buy here, even some branded prebuild battery and solar set price can be more expensive than the house price itself here lmao, that's why people here still hunting for old laptop battery, not only it's dirt cheap compared than other option, even used LFP cell price still high here, but also there's still no facility to recycle any lithium battery here.

[@user-qr4jf4tv2x]

i see so a thick wire is not always the best i see alot fully soldiering a large bar which is bad

[@kevinmccray8351]

So wait a second. Why the categorical dismissal of hot glue? If the cells are appropriately spaced, say with silicone o-rings, there wouldn't be anything inherently unsafe about keeping them together with hot glue would there be? Of course, assuming that everything is well isolated with fish tape or whatever.

[@snorttroll4379]

hot glue melt. hot glue people too greedy and dumb to keep cells spaced. no way for cell to drop out of pack if hot.

[@kevinmccray8351]

@@snorttroll4379 Based on your spelling and grammar I don't think you've earned the right to be calling anyone dumb m8.

[@-Gunnarsson-]

I suppose its faulty assemble. A broken BMS or charger. The cells wont just self combust for no reason

[@vaxt]

"Because Tesla does it" is not enough to justify the bold statements in this video.

[@famvirious]

I just want to make a 60v 20amph battery for my bike so I can put on a better controller and motor

[@Inmate533]

I remember when companies were going to make hydrogen powered cars and everyone screamed about how dangerous it was. Now cars are being powered with Li-Ion batteries, and no one is saying anything.

[@Awrethien]

Well they are still dangerous but in different ways. Despite what the news reports explosive failures of Li batteries is extremely rare. More like a fast burn much like standard fossil fuels. When a pressure vessel with a combustible gas fails and there is a fire a spectacular failure *is* the norm.

[@Tb0n3]

What are you talking about? Lithium batteries have under one mega joule per kilogram energy density while TNT has 4.6. gasoline has 46.

[@iceman1980sc]

The problem is they use sheep BMS systems so it Overheated components' en start fire

[@krishnansrinivasan830]

Nice & Thanks :)

[@ElectricVehicleSpace]

Welcome!

[@널리세상을이롭게]

I am always watching your video. I am running an electric board club in Korea and have 17,000 members. I want to collaborate with you when I have a chance.

[@ElectricVehicleSpace]

pm me

[@joshdesbiens7203]

Josh

[@tde04014]

think we need a lot of sand deposits near every road when electric cars gets more popular, as sand is the only way of make the fire more controllable

[@ElectricVehicleSpace]

We need technology not sand.

[@snorttroll4379]

what do you propose to stop runaway batteries? perhaps that they drop out of their holder and onto the ground if they become too hot? a string holding them up that melts and lets the cell fall either into the ground, or into a safe area in a pack. perhaps each cell should be spring loaded.@@ElectricVehicleSpace

[@2010stoof]

Ive seen some really sketchy packa built.

[@Doviruses.existbaileyonodysee]

aw man. It ended too soon 😅.

[@ElectricVehicleSpace]

what exactly?

[@Doviruses.existbaileyonodysee]

@@ElectricVehicleSpace haha. No it was just really good to watch. It could have been an hour long.😁

[@zentyrant]

wonder if someone actually have a battery at the size of building

[@ElectricVehicleSpace]

tesla may have something close to that size.

[@metatechnologist]

Yea there really is. Tesla sells solutions for power companies. The battery for the seed bank in Norway is huge.

[@sebw3964]

Why i should watch Tesla Videos.Thos Cars blowing up too

[@ElectricVehicleSpace]

They are the best and have less accidents versus the rest of the world

[@geemanns4949]

alot of things work to build lith ion batts, there's is not only one way to make them....?

[@ElectricVehicleSpace]

Yes but it has to be safe

[@pauls5745]

not to downplay safety concerns, but LI batts are only mildly dangerous. not extremely so as stated in the vid. extremely dangerous is the level of household mains

[@pauls5745]

I would say most accidents with battery packs result from underestimating current capacity of connections and wiring. I see so many ppl using like 12awg wire trying to build 50A packs but you know it's gonna get hot at that draw

[@idk8964]

I can see why most people pay 3-4x more for premade lifepo4 batteries. I'm wayyy too dumb for this.

[@snorttroll4379]

the premade ones do not come with this. so it's just a ripoff.

[@eBoard3R]

👌🏼👌🏼

[@ahah1785]

My super expensive bosh battery pack does not have individual cell fuses...they are solid spot-welded 6P in 10S config...go figgure...

[@pianojacq]

Yes, this is pretty common. I think that the reason Tesla uses individual cell fuses is that their packs have so much spare capacity that an individual cell dropping out isn't going to cause a problem, the packs are never fully charged or discharged and the rate of discharge per cell is low enough that the fuses in practice will never go. But when packs contain fewer cells having a good cell drop out is an immediate cause for concern, and the biggest risk is a bad cell that starts to discharge itself and its neighbors at a high rate. That's why the BMS in a Bosch pack tends to brick the whole pack if it believes that one or more cells are faulty (the dreaded 'LED 2-4 error', which is not user resettable). Clearly, Tesla has the capability of creating very precise fuse wires, they wirebond them to the cell and the bus bar, and they can do this with such repeat accuracy that the wire will blow at a predictable current. Doing this in a hobbyist setting is going to be very hard to replicate accurately, I would expect at least a 50% variance from one such cobbled together fuse to the next if it isn't done robotically as the video shows.

[@snorttroll4379]

nope. just use a wire of known proportions. or use glass ampulle fuses. @@pianojacq

[@EnlightenedSavage]

Your first statement is completely false and misleading.

[@lemonjuice6177]

Agree

[@OutOfNameIdeas2]

No it's true lol. They don't explode as instantaneous though. Meaning it's not as dangerous as an actual explosive.

[@OutOfNameIdeas2]

(in terms of explosion damage. They will burn for quite a while and take everything around them with it. Especially the larger packs. Teslas burning for days for an example. If I remember correctly a single 18650 is quite a few x more energy dense than Dynamite sticks)

[@박메롱-k9z]

Companies that sell new, high-quality batteries do not sell lithium-ion batteries to individuals. Most of the secondary batteries that individuals can purchase are counterfeit, used, or fake batteries, which can quickly lead to fatal fires or explosions.

[@ElectricVehicleSpace]

That's incorrect!

[@2010stoof]

Cells heating are more about the connections in series than anything. Most think you can buy cheap nickle plated strips and its all good except when you have high drain. Or use cells that arent designed for the amp draw. Especially the wells at the positive and negative sides of the batteries. Too many stupid videos showing bad practices

[@creeperproof2]

Dude no, cell level fuses are not practical or even a good idea. If the fuses pop you are very likely to lose control and crash at high speed. I would rather try to slow down a burning board or scooter then be thrown off at 40 mph Please don't spread miss information about electric vehicle battery's. Cell level fuses only make sence in much bigger packs or with reclaimed cells where the failer rate is much higher

[@ElectricVehicleSpace]

So wrong!!! I tested a board at 40mph and the entire group of cell on one side (pack was 12S4P) 1P disconnected and the vesc just went off and the board slowly came to a stop. I thought the vesc died but after seeing the heat shrink melted I saw the fuses worked. Before writing none sense do a test!

[@infiniteoffset]

If fuse pop, then you are in a lot less trouble riding board without brakes, than riding potential fireball, which will also have no breaks, because after the short there will be no power. Key is to have right fuse so it doesn't blow prematurely.

[@infiniteoffset]

I have been riding single 40A fuse on 10S dual motor setup with each VESC set to 50A and never popped even on hill climbs.

[@creeperproof2]

@@infiniteoffset yes one main fuse is a good idea, however cell leval fuses is stupid , first off can draw 40a per cell there is no cell fuse on the market for that, second. yes if you where on a perfectly flat nice tarmacked road, sure you could roll to a stop and bobs your uncle your fine. however if you are on a steep hill or off-roading having a brake failure could literally kill you.

[@creeperproof2]

@@ElectricVehicleSpace HAHAHA, please tell me how i should place a cell level fuse for 40a, please I'm waiting......

[@martonlerant5672]

Showing "i take Elon'sword for it" is not gonna inspire confidence. ...or well i guess the video aged like fine milk. As since its publishing more and more people became aware of Elon "techjesus" Musk technical expertiese (or lack thereof).

[@Jetsonn]

Just more propaganda, move along