As I understood this cell fuses: This fuses are not to prevent shortcircuit of the whole pack. It is for a shortage protection in a cell itself. If you meassure peak current it will be always high, because it is a heat fuse. So always the integral of current and time is decisive.
@@HBPowerwall The iCharger X6 can work as a powersupply. And you can control the voltage and amperage output using a special power mode. Though you have to control it with the little nubby switch on the side but it can be done. I've used it as a Power Supply for nickel plating before :)
@@SirCrest electroplating is not a short circuit, as the chemical reaction is the load. The phone charger wouldn't be able to output a high enough current to simulate a battery short circuiting or to blow a fuse over 1 or 2 amps.
@@matthewmeuleman3369 iCharger X6 can output 30amps which is well above what the fuse is supposed to do. Only mentioned electroplating as a use that some people use for a regulated power supply with current limiting. Didn't say it was related to fuse testing.
In the test of the nikkel fuse the weight of the cable is pulling on the red hot fuse. On your battery fuse there is no pressure when it is red hot. That is why I think your battery fuse held.
If you use a charger to regulate the charge current, and charge a battery through the fuse then we should be able to see how much a fuse can carry without blowing, and what level of current would cause it to blow within a few seconds.
From what I understand in this test is that the cells are only capable of 8-10amps max . The nickle fuse sheets are rated to blow at a similar current. This is just a recipe for disaster in my opinion. In order for this to be safe and practical they must blow at a much lower current like .5 or 1 amp. Furthermore, there should be room to remove damaged cells for repairs. If this was tested on cells with a better discharge rating I'm 100% certain all fuses would blow significantly faster.
@@angelon7095 you would need a massive pack, I am designing all my packs for 100amp and that would mean I would need 200 cells per pack. I aim to have about a max of 2.5 Amp draw per cell, and am going to use 3amp fuse wire that normally burns at 5-6amp
@@mondotv4216 the less you draw from each cell the longer they last on a charge and a longer life cycle too, as far as my understanding goes, but that doesn't really have anything to do with the fuse threshold. I guess using recycled batteries you don't want to take too much risk, but I would think up to 2.5a being pretty safe.
Pete, the melting metal coming from the fuse would be of concern too. I guess the vertical orientation of the mounted pack, would help alleviate it dropping into the cid area.
Looks like it'll keep an entire pack from discharging into a bunk cell, so if someone has worries about that then it'll calm those fears. Either way I think it looks like a VERY easy way to assemble packs if you use a spot welder. And will even reduce or eliminate property damage caused by an accidental unstoppable short circuit outside of the pack.
also, re watching teh "glowing" footage, if those cells didn't actually blow the fuse on the other side I wonder if they're internally open circuit now? The cells internal bonding / CID may have failed on some of them.
if you look closely you can see a fuse or two blow on the other side - 5 fuses in total have failed BUT after your comment there are also CID issues also that I didn't consider at the time. Will include this information in Debreaf video
Pete, your large pack fuse of course would not blow or at-least not in the time-frame you had it connected.. you have to remember mate if that was an 80p pack then that sucker could potentially do 144amps without blowing due to the fact 80cell's x 2 amp each = 160amp for that pack at an easy 2 amp each cell minus drops due to internal resistances lol. If you wanna blow a fuse youl have to have one that's not attached to anything just a fuse between + & - as your test on your 80p pack fuse had what we call parallel path's. Hope that helps clarify why you saw 144amps.
Ok this is what I think!!!! This nickel fuse strip is design for when one cell and only one get a short circuit. So, let's we said you need to connect your short circuit cable just Right on Top of negative or positive on a single cell. And the fuse strip will melt. That it. Grating from Venezuelan Citizen and Texas.
I've got an order in for this nickel strip. When it comes in, I'll be doing a test with a lab-grade benchtop power supply to see at what current/time the fuse actually blows. Hopefully, I'll find the time to actually make a video on it.
@@HBPowerwall Will do! My plan is to characterize the fuses like one would a traditional fuse and make a graph of current vs. time to blow. We just got in some nice lab power supplies that can do up to 30A, but worst case I'll use an 18650 with a current clamp and oscilloscope. Pete, I was terrified those cells were going to go into thermal runaway on you during your short test. I'm glad everything ended safely!
Have you ever done a soldered and none soldered fuse test. Wire of equal lengths, one which has been soldered a layer of solder on the wire and one which is straight off the reel. How much difference in current draw does it make to blowing current?
The Cat S60 smart phone is inbuilt with a better FLIR camera than your iPod/ attachment. It shows a temperature/ colour scale on the right hand side of the screen, so no need for crosshairs telling you what a single point of temperature is, when you know the temperature of the whole screen. This feature technically makes it a tool, for taxation purposes ;)
Peter, saying “I don’t pretend to know a lot” Is the opposite to the knowledge you’re imparting here! Great video! This test certainly opens up a can of worms. (for a better word). It appears that if the limits are near, you end up with heating elements!! 🤔
Would a bench top power supply have been a better power source? I am thinking that being able to edge up the amps over different periods of time instead of having a dead short each time would be a better test that would give a distribution versus time instead of a bunch of points close to a single value. Also, how about rigging up a test rig that test wires and nickel fuses comparatively under the same circumstances while clamped at both ends with the same mechanical pressure? The sudden dead shout short could be imitated by installing a quick snap switch somewhere in the circuit while the power supply is running at preset values. The bench top power supply could be set at several difference amperages and the results could be recorded using your phone camera using the same recording speed so that a time to destruction can be found. Also, using the same test rig, the power supply could be set to run somewhere between 80% and 100% of expected load which could tell a lot about the fuse behavior under continuous load greater than 80% of expected load. A heat camera could be really handy in recording temperature increase versus time in this setup. Finally, I would think that distorting the nickel before testing it would have some sort of impact because of the likelihood of weak spots being bent into the fuse itself. I would think that clipping the fuse free and comparing it length for length to the wire without distortion of either would be a better comparative test. Thanks.
The resistivity of Ni is higher than the material your fuses are made of; so the Ni fuses heat up faster, hence they should blow faster. But I am rather suspicious about how thick that Ni fuse is. Much thicker than a fine strand of copper wire. I tested very fine strands of pure copper which, as you know, is a superior conducter. Those hair like copper strands blow at 6 amps. A dead short makes them blow instantly.
You do not need a regulated PS. You can easily create a closed circuit in which you include a fixed power resistor, like a 4 ohm 50 watt or 100 watt resistor. Then you increase the current in the circuit in steps in by adding one cell in series at a time. So you test with rising voltages over a fixed power resistor with 4 V - 8 V - 12V - 16V ... increments. Current rises as voltage rises.
The way to test a fuse to slowly increase the current through it to see how much current it can carry before it opens. You do this using a bench power supply operating in current limit mode (set the voltage to a couple volts, set current to zero) then increase current slowly until the fuse opens. You're not looking for how fast it blows, rather, how much current it can carry before it does open. Ideally, the fuse should open somewhere near the cells maximum safe current. Your test at 15 minutes is interesting. It shows that a single cell that shorts in a large parallel array should blow its own fuse, but it will carry a lot of current (too much?) before it actually opens.. Overall, this is an interesting concept, but the fuses just don't blow at a low enough current for me to consider them useful (as fuses)..
You could use the kweld to test the instantaneous blowing point. Easyer to rig up and a firmware upgrade may make a good test script with test output if you know someone that can programme it. Even without a dedicated option in the kweld just "welding" from the cell pad to the bus sheet with increasing Joules.
As you could see from the video, the fuses around the nodes blow up first, and those further away stay in tact. The reason for this is that there is a voltage drop from the point of contact further on into the material , because of the high current. In the design of the total block, you use an extra thick copper wire to enhance the conductance. This was not present in your test. If you could repeat the test with those wires added, you will see better results.
Pausing the video at 8:45 and going frame by frame I saw from .8 up to 2.0 on the meter. The molten metal is concerning though. To watch frame by frame I pause the video then use the greater than and lesser than arrows above the period and comma keys.
Curious as to using a TEG peltier gen for the heat distribution collecting even if its a volt with no amps would be neat to see. Conformal coating could help with many of your board concerns.
Would of been interesting if you measures the current in the dead short test, you could then work out what each fuse was drawing (current / 20 cells). If you needed around 24A to blow one fuse quick then for 20 cells you would need 480A.
Wondering how critical fuses are for this application. I have none, I have just been using hardwire house electrical bus bars and linking the cells together using small telephone cable which is also hard wire. I think it was for inside the walls, anyway they definitely handle a lot more than 10 amps of current so they are definitely not useful as fuses. The wire you've shown looks super thin though, what is the amperage I should be aiming for when it comes to fuses? 10 amps seems to be a common target but I am not sure.
I use the 2p and if needed just cut out a square around the fuse with clippers then re-weld a square with the fuse on when cells replaced, its the only way I've come up with.
Connect the crocodile clip to the underneath of the fuse sheet then the clip falls away from the sheet when the fuse blows?! You won't cause secondary shorts.
Shunt and oscilloscope if you want to accurately measure the fuses break currents. The fuse could almost be considered a "5A" fuse that breaks under a second at 9A. I have quality shunts, oscilloscope, solid state switches, bench power supplies, electronic or digital load and also can use a Headway high discharge cell for testing. Will do my own more accurate test.
You just have to do what you do to get it out and replaced - but one would hope that not adding heat via soldering will reduce those issues even further.. making it less necessary to upgrade cells
So the whole idea of the spiral parts on the nickle strip is to act like a fuse right? I'm thinking that because it is so long that it acts like a resistor, causing the battery to heat when doing long time charges and discharges. I think having the shorted amount of fuse section possible would be best. That meter won't be accurate as it has a certain polling rate and it most likely won't pick up the actual peak in current but rather on the come up.
the spiral would seem to be a compromise between being able to reach the cell without any stress or kinks & amp rating. Meter is not at all accurate :( But that said it was fun to play and enjoy the learning curve even if it was very wrong - now to try do it right.
@@HBPowerwall yes the fuse in series would be the weak link. weld the fuse to 1 nickel strip or wire and connect it to a strong pack it should work and be safe. i got 300w from one of those useless devices and tested all 20x100Ah nicd from my ev :P
@@HBPowerwall yeah you can use the 20p pack as the bulk power supply, and just have a single fuse link between it and your powerwall. Charging or discharging shouldn't matter just adjust your current limit in charging/discharging until it blows.
This method had potential danger. It works well when you apply an aggressive dead short. However, If you were to apply a current closer to the failure point of the nickel fuse, it would lead to the nickel fuse glowing orange/white hot, conducting heat into the cell(s). The cell would absorb the heat resulting in catastrophic failure of the cell. It's better to use a fuse material with a lower melting point.
True - all fuses only work at their given load. I can short out my 80p packs with little tiny fuse wire and exactly the same thing happens. But when only one cell is shorted the fuses vaporise. Best part about this is the nickel acts as a large heat sink and does a great job of dispersing heat. Pros and Cons could be unsuccessfully argued for all time. But thankyou for your input helps everyone make their own mind up on what is acceptable safety wise. Have a good day.
Hey could u provide a link for those sheet of nickel, covering 4*5 cells... Sorry if u already did, can't seem to find it anywhere as I don't know what it's called ... Thx for all u do.. it helps even old school electronic fiddler's 🥴
@@HBPowerwall I just finished a 85AH 24v battery using these sheets. I really don't think this is a good way to fuse these. The fuse strip as shown in your video is not a good fuse. There's not enough of a bottleneck for current, the entire strip will just sit there and glow. Imagine your bms failing and shorting your pack with enough current to make these glow orange. You basically would have several KW of resistive elements glowing orange 1mm away from the insulator, quickly melting the insulator on the top of the cell, Then the fuse slumps across it ect and shorts the cell. I like the efficiency of it but I don't think its a proper fuse. It also seems very rare for a cell to fail in a way that would consume enough power to blow this fuse. Id imagine a cell that's got a few amp internal discharge would not blow this fuse but still be consuming enough power to go into runaway. Another thing to keep in mind with these is safety on install. I was laying a 3p sheet down and one of the fuse pad things slipped right into an 18650 and shorted, melting the insulation ring and shit. Had to pull apart the pack to get that cell out. Took me a minute to figure out how I created a short circuit! That was VERY easy to do accidentally.
Simple.. if the fuse is 8 amp x 20 it’s now a 80 amp fuse ☝️and you used them on both sides.. so 2x80 amps is 160amps .. you turned that pack into a heater .
I would expect a direct short to pop all the fuses instantly. Anything else, like creating heat coils we saw, would be too dangerous for the batteries. Think I'll just stick with fuse wires.
if the battery larger, with a PROPER direct short & the fuses, wires, busbars were the correct size for the application I would agree.. this was just a fun hack test.
Yep, and the nickel just wicks away the heat very effectively also. This is not how they are designed to blow. If only one cell goes bad the fuse vaporises
That 144 amp was due to the fact your alligator clamp dropped and touched the actual metal plate after it blew the fuse. It wasn't 144 amps thru that fuse lol..
How thick is that nickel? I did a few napkin calcs and I worked out that if the nickel between the cells is 10mm and you are allowing a 5 cell wide pack and if the nickel is 0.2mm you would only be able to run 20a continuously at 60°. So your 30a at 65° is probably pretty close, does look like you either need thinker nickel or solder some bus bars for larger currents like 100a.
You absolutely shuld use need a bench top power supply to test fuses. If you insist of doing it like this with batteries instead of a power supply or electronic load you need a >10MHz oscilloscope across a shunt or a magnetic oscilloscope probe to catch the flank, not a crappy magnetic clamp meter' max hold.
you should check out some of my older videos about cell fuses - this will make you eith smile or laugh lol 1. th-cam.com/video/RAfMq_EZ4oA/w-d-xo.html 2. th-cam.com/video/5hiQCD8LPcs/w-d-xo.html
@@HBPowerwall I like that old video. You showed that the fuse doesn't burn. By the way every fuse worth it's salt should come with a sheet like this: www.swe-check.com.au/images/content/time_current_curves.gif So for example the fuse rated for 250mA will burn in 1 second when it sees 1 amp, but it will burn in 0.1 second if it sees 2.1 amps. You just follow the curve what it is rated for and read the seconds it will burn in for which current.
Cell replacement could be easy if you use mini magnets instead of spot welding. BTW, I would not fool around with extreme currents inside the house; exploding battery packs are not a joke.
I'm going to guess that the reason they didn't blow in the small pack was because there is enough nickel there to dissipate the heat fast enough to keep them from blowing. On the larger pack, there's too much current for the plate portion to absorb the heat. And yeah, I'd say that one cell is toast 😜
I would love someone in the community to hit me up so i can learn how to do these tests right and with a little more consistancy! Much to learn still...
@@HBPowerwall Hi mister! Go to EBay search for 500amp shunt you should see one for $29.16au. You can use that with a scope or a good multimeter with min and max. It puts out 50mv @ 500amps so at 500 amps it would show 50mv and 100 amp show 10mv and so on.
14A-144A each cell is really high current.. and lets face it _ there are really not many case where cells short like that _ and each pack having 100 cell _ will ned 150A to 1500A _ thats insane _
No fuses will take so much time even after a short circuit check out Tesla fuses how fast they blow if the cells are shorted . I feel this design is complete disaster.
to be fair this isn't a very good test at all doing the whole pack short with a cable that's too small. all fuses blow at their rated capacity - it's hard to know if i was exceeding that. it was a shit test but I did enjoy it
@@HBPowerwall there is a design flaw in this fuses . Fuse getting red hot but not blowing is a flaw from my knowledge this fuse should have some physical stress so that when the mechanical strength goes down the fuse disattach from the battery so it fuses out in the perfect current load
@@HBPowerwall true, but in a normal use the drain is usually not constant, and how long does it take for the fuse to break? :) If its too long it can start burning:/
@@williamwestonn these fuses are not a security for a shorted pack. these fuses are for shorted cells.You got some serious problems if you whole pack is shorted. Tell me how you want to short a whole pack?
@@HBPowerwall Not this time, otherwise my eyeballs would have bursted into flames hehehe You said "You can see heah somweh" but I can't see what are you point at :)
Water is to halt the thermal run away to other cells not put it out. Ask any fire department how they deal with an EV fire... Water & HOURS AND HOURS of it!
@@HBPowerwall agree. Probably the only thing that kept one my one thermal cell from catching fire was cooling it in a cup of ice water. There's no stopping an internal short, but if you get rid of the heat as fast as it's making it, it should be ok.
vaneay vaneay there’s no metallic lithium in a rechargeable li-ion battery. Water is no problem and is the recommended method, along with aqueous firefighting liquids/foams, for fighting secondary Li-ion fires. Only non-rechargeable “primary” li-ion batteries have metallic lithium in them which can be a problem is the battery is opened up.
As I understood this cell fuses: This fuses are not to prevent shortcircuit of the whole pack. It is for a shortage protection in a cell itself.
If you meassure peak current it will be always high, because it is a heat fuse. So always the integral of current and time is decisive.
Yes, it's wasn't a good test but I did learn stuffs so that's a win..
Hook it up a bench power supply so you can control the amps going thru it
Unfortunately I don't have one - but thinking it might be a good investment
@@HBPowerwall The iCharger X6 can work as a powersupply. And you can control the voltage and amperage output using a special power mode. Though you have to control it with the little nubby switch on the side but it can be done. I've used it as a Power Supply for nickel plating before :)
@Mafiashotz doesn't he gave one, thought I saw it in one video, at least the cheap "150W" one. Should be good enough for a single fuse
@@SirCrest electroplating is not a short circuit, as the chemical reaction is the load. The phone charger wouldn't be able to output a high enough current to simulate a battery short circuiting or to blow a fuse over 1 or 2 amps.
@@matthewmeuleman3369 iCharger X6 can output 30amps which is well above what the fuse is supposed to do.
Only mentioned electroplating as a use that some people use for a regulated power supply with current limiting. Didn't say it was related to fuse testing.
Great tests! Thanks for taking time to record/video all of it.
Thanks Mike :)
In the test of the nikkel fuse the weight of the cable is pulling on the red hot fuse. On your battery fuse there is no pressure when it is red hot. That is why I think your battery fuse held.
If you use a charger to regulate the charge current, and charge a battery through the fuse then we should be able to see how much a fuse can carry without blowing, and what level of current would cause it to blow within a few seconds.
@Abel Sage You're right, I don't give a damn, and neither should anyone else.
@@ahaveland just report it as spam
From what I understand in this test is that the cells are only capable of 8-10amps max . The nickle fuse sheets are rated to blow at a similar current. This is just a recipe for disaster in my opinion. In order for this to be safe and practical they must blow at a much lower current like .5 or 1 amp. Furthermore, there should be room to remove damaged cells for repairs. If this was tested on cells with a better discharge rating I'm 100% certain all fuses would blow significantly faster.
having a cell fuse at .5amp blow would increase resistance beyond any reasonable level to be practical or even safe.
@@HBPowerwall Even if you have a large parallel pack ?
@@angelon7095 you would need a massive pack, I am designing all my packs for 100amp and that would mean I would need 200 cells per pack. I aim to have about a max of 2.5 Amp draw per cell, and am going to use 3amp fuse wire that normally burns at 5-6amp
Why? A lot of the individual cells (like the Panasonics) are rated at over 3 amps continuous. So why fuse them for 1 amp?
@@mondotv4216 the less you draw from each cell the longer they last on a charge and a longer life cycle too, as far as my understanding goes, but that doesn't really have anything to do with the fuse threshold. I guess using recycled batteries you don't want to take too much risk, but I would think up to 2.5a being pretty safe.
Pete, the melting metal coming from the fuse would be of concern too. I guess the vertical orientation of the mounted pack, would help alleviate it dropping into the cid area.
it cools so fast i don't think it'll be an issue but I understand your concern when you see it in slow motion
Looks like it'll keep an entire pack from discharging into a bunk cell, so if someone has worries about that then it'll calm those fears. Either way I think it looks like a VERY easy way to assemble packs if you use a spot welder. And will even reduce or eliminate property damage caused by an accidental unstoppable short circuit outside of the pack.
also, re watching teh "glowing" footage, if those cells didn't actually blow the fuse on the other side I wonder if they're internally open circuit now? The cells internal bonding / CID may have failed on some of them.
if you look closely you can see a fuse or two blow on the other side - 5 fuses in total have failed BUT after your comment there are also CID issues also that I didn't consider at the time. Will include this information in Debreaf video
Pete, your large pack fuse of course would not blow or at-least not in the time-frame you had it connected.. you have to remember mate if that was an 80p pack then that sucker could potentially do 144amps without blowing due to the fact 80cell's x 2 amp each = 160amp for that pack at an easy 2 amp each cell minus drops due to internal resistances lol.
If you wanna blow a fuse youl have to have one that's not attached to anything just a fuse between + & - as your test on your 80p pack fuse had what we call parallel path's. Hope that helps clarify why you saw 144amps.
Why do you have fuses on both sides? If there was a short wouldn’t blow the fuse if it was only on one side of the battery?
Nice rough-n-ready test Pete. Does the fuse design work? Yes. Is it quicker to build? Yes. Sorted.
I love them - got it down to 10-12 min for both sides of a 80P battery. Only limitation is the heat in the electrodes
Nice. This might be the final nudge towards getting a spot welder.
05:21 diy welding machine
Cheap as it gets lol
Ok this is what I think!!!! This nickel fuse strip is design for when one cell and only one get a short circuit. So, let's we said you need to connect your short circuit cable just Right on Top of negative or positive on a single cell. And the fuse strip will melt. That it. Grating from Venezuelan Citizen and Texas.
What a confusing Test!!! Holy Moly!!!! But I am glad you did it, can't wait to see the discussion now over on the forum!!
I think this video has more questions than answers in it..
I've got an order in for this nickel strip. When it comes in, I'll be doing a test with a lab-grade benchtop power supply to see at what current/time the fuse actually blows. Hopefully, I'll find the time to actually make a video on it.
Let me know I would be keen to see a proper test rather than my BS lol
@@HBPowerwall Will do! My plan is to characterize the fuses like one would a traditional fuse and make a graph of current vs. time to blow. We just got in some nice lab power supplies that can do up to 30A, but worst case I'll use an 18650 with a current clamp and oscilloscope. Pete, I was terrified those cells were going to go into thermal runaway on you during your short test. I'm glad everything ended safely!
Have you ever done a soldered and none soldered fuse test. Wire of equal lengths, one which has been soldered a layer of solder on the wire and one which is straight off the reel. How much difference in current draw does it make to blowing current?
Math will tell you those results
Ya got a little touch of craziness inya.. I like that!
I call it fun, but we can run with crazy for now!
Hi I am looking to build a mini power wall or batteries for my rv to go off grid I have batteries . Just need to know the best config to go with
These would be a good choice for an rv due to vibrations.
The Cat S60 smart phone is inbuilt with a better FLIR camera than your iPod/ attachment. It shows a temperature/ colour scale on the right hand side of the screen, so no need for crosshairs telling you what a single point of temperature is, when you know the temperature of the whole screen. This feature technically makes it a tool, for taxation purposes ;)
I need candycrush on my phone so i can do something in my down time onsite - also a taxation consideration lol
@@HBPowerwall it's a shame when you can't play practical jokes because of site rules. Impractical jokes are also frowned upon.
Peter, saying “I don’t pretend to know a lot” Is the opposite to the knowledge you’re imparting here! Great video! This test certainly opens up a can of worms. (for a better word).
It appears that if the limits are near, you end up with heating elements!! 🤔
You guys teach me more than i've ever learnt at school. I just share my thought process basically
Would a bench top power supply have been a better power source? I am thinking that being able to edge up the amps over different periods of time instead of having a dead short each time would be a better test that would give a distribution versus time instead of a bunch of points close to a single value. Also, how about rigging up a test rig that test wires and nickel fuses comparatively under the same circumstances while clamped at both ends with the same mechanical pressure? The sudden dead shout short could be imitated by installing a quick snap switch somewhere in the circuit while the power supply is running at preset values. The bench top power supply could be set at several difference amperages and the results could be recorded using your phone camera using the same recording speed so that a time to destruction can be found. Also, using the same test rig, the power supply could be set to run somewhere between 80% and 100% of expected load which could tell a lot about the fuse behavior under continuous load greater than 80% of expected load. A heat camera could be really handy in recording temperature increase versus time in this setup. Finally, I would think that distorting the nickel before testing it would have some sort of impact because of the likelihood of weak spots being bent into the fuse itself. I would think that clipping the fuse free and comparing it length for length to the wire without distortion of either would be a better comparative test. Thanks.
Try using an analogue meter with a shunt to measure s/c current.
I have an analog one somewhere, would ba .fun test to do
The resistivity of Ni is higher than the material your fuses are made of; so the Ni fuses heat up faster, hence they should blow faster. But I am rather suspicious about how thick that Ni fuse is. Much thicker than a fine strand of copper wire. I tested very fine strands of pure copper which, as you know, is a superior conducter. Those hair like copper strands blow at 6 amps. A dead short makes them blow instantly.
You do not need a regulated PS. You can easily create a closed circuit in which you include a fixed power resistor, like a 4 ohm 50 watt or 100 watt resistor. Then you increase the current in the circuit in steps in by adding one cell in series at a time. So you test with rising voltages over a fixed power resistor with 4 V - 8 V - 12V - 16V ... increments. Current rises as voltage rises.
The way to test a fuse to slowly increase the current through it to see how much current it can carry before it opens. You do this using a bench power supply operating in current limit mode (set the voltage to a couple volts, set current to zero) then increase current slowly until the fuse opens. You're not looking for how fast it blows, rather, how much current it can carry before it does open. Ideally, the fuse should open somewhere near the cells maximum safe current.
Your test at 15 minutes is interesting. It shows that a single cell that shorts in a large parallel array should blow its own fuse, but it will carry a lot of current (too much?) before it actually opens..
Overall, this is an interesting concept, but the fuses just don't blow at a low enough current for me to consider them useful (as fuses)..
Yes, i'm going try this test again as now i have bench supply, just don't have much spare time
You could use the kweld to test the instantaneous blowing point. Easyer to rig up and a firmware upgrade may make a good test script with test output if you know someone that can programme it.
Even without a dedicated option in the kweld just "welding" from the cell pad to the bus sheet with increasing Joules.
Sounds possible, but the 'community spotwelder' is hardly ever here any more booked out weeks in advance
As you could see from the video, the fuses around the nodes blow up first, and those further away stay in tact. The reason for this is that there is a voltage drop from the point of contact further on into the material , because of the high current.
In the design of the total block, you use an extra thick copper wire to enhance the conductance. This was not present in your test. If you could repeat the test with those wires added, you will see better results.
I agree - I could have done the tests much better.
Pausing the video at 8:45 and going frame by frame I saw from .8 up to 2.0 on the meter. The molten metal is concerning though. To watch frame by frame I pause the video then use the greater than and lesser than arrows above the period and comma keys.
that is 0.3 of a second from the raw footage!
Curious as to using a TEG peltier gen for the heat distribution collecting even if its a volt with no amps would be neat to see. Conformal coating could help with many of your board concerns.
Would of been interesting if you measures the current in the dead short test, you could then work out what each fuse was drawing (current / 20 cells). If you needed around 24A to blow one fuse quick then for 20 cells you would need 480A.
It was 220amps inrush, didn't see constant. That footage was seen after release, will inc it into next video
In that final pack test did the fuses (that went dark) actually blow or was it just the cells that failed (CID or PTC activation)?
some it was the fuse on the other side, some were CID
HBPowerwall thanks! I totally forgot about the fuses on the other side.
Wondering how critical fuses are for this application. I have none, I have just been using hardwire house electrical bus bars and linking the cells together using small telephone cable which is also hard wire. I think it was for inside the walls, anyway they definitely handle a lot more than 10 amps of current so they are definitely not useful as fuses. The wire you've shown looks super thin though, what is the amperage I should be aiming for when it comes to fuses? 10 amps seems to be a common target but I am not sure.
I use the 2p and if needed just cut out a square around the fuse with clippers then re-weld a square with the fuse on when cells replaced, its the only way I've come up with.
I've done it that way also just spotweled some 32awg fuse wire into place..
Is there an equivalent to batteryhookups in Australia? I've not been able to find batteries even close to the prices you list in your spreadsheet...
We are working on it! Stay tunned
Connect the crocodile clip to the underneath of the fuse sheet then the clip falls away from the sheet when the fuse blows?! You won't cause secondary shorts.
Shunt and oscilloscope if you want to accurately measure the fuses break currents. The fuse could almost be considered a "5A" fuse that breaks under a second at 9A.
I have quality shunts, oscilloscope, solid state switches, bench power supplies, electronic or digital load and also can use a Headway high discharge cell for testing. Will do my own more accurate test.
Can't wait to see it Shannon - How can i help?
@@HBPowerwall have everything needed including Tom's fused strips.
@@GENcELL2014 Where will you present your results, Shannon? On your TH-cam channel or on the forum? Thanks!
@@the3rddecline Facebook post in DIY Powerwalls and DIY Battery groups and I'll make a thread on Secondlifestorage.com
Great Video! So what do you do after a cell blows a fuse and is no good? How do you replace the cell and refuse it?
You just have to do what you do to get it out and replaced - but one would hope that not adding heat via soldering will reduce those issues even further.. making it less necessary to upgrade cells
So the whole idea of the spiral parts on the nickle strip is to act like a fuse right?
I'm thinking that because it is so long that it acts like a resistor, causing the battery to heat when doing long time charges and discharges.
I think having the shorted amount of fuse section possible would be best.
That meter won't be accurate as it has a certain polling rate and it most likely won't pick up the actual peak in current but rather on the come up.
the spiral would seem to be a compromise between being able to reach the cell without any stress or kinks & amp rating. Meter is not at all accurate :( But that said it was fun to play and enjoy the learning curve even if it was very wrong - now to try do it right.
can't you use your constant current load to test the fuses?
I don't have such a device (or do i & i don't know it?)
@@HBPowerwall i saw on a video that you had two: 150W 180W Constant Current Discharge Capacity Tester More in depth :)
Ooh they are long gone - terrible devices - wonder if i can just use the iCharger X6... that would have to work set it to 10a discharge on single cell
@@HBPowerwall yes the fuse in series would be the weak link. weld the fuse to 1 nickel strip or wire and connect it to a strong pack it should work and be safe. i got 300w from one of those useless devices and tested all 20x100Ah nicd from my ev :P
@@HBPowerwall yeah you can use the 20p pack as the bulk power supply, and just have a single fuse link between it and your powerwall. Charging or discharging shouldn't matter just adjust your current limit in charging/discharging until it blows.
This method had potential danger. It works well when you apply an aggressive dead short. However, If you were to apply a current closer to the failure point of the nickel fuse, it would lead to the nickel fuse glowing orange/white hot, conducting heat into the cell(s). The cell would absorb the heat resulting in catastrophic failure of the cell. It's better to use a fuse material with a lower melting point.
True - all fuses only work at their given load. I can short out my 80p packs with little tiny fuse wire and exactly the same thing happens. But when only one cell is shorted the fuses vaporise. Best part about this is the nickel acts as a large heat sink and does a great job of dispersing heat. Pros and Cons could be unsuccessfully argued for all time. But thankyou for your input helps everyone make their own mind up on what is acceptable safety wise. Have a good day.
heya that is 1 more test I need to see more because I have those nikkel strip w fuses withs I want to use
Hey could u provide a link for those sheet of nickel, covering 4*5 cells... Sorry if u already did, can't seem to find it anywhere as I don't know what it's called ... Thx for all u do.. it helps even old school electronic fiddler's 🥴
batteryhookupdotcom
bit.ly/2M7M1Y7
Can one get this for 21700 and if so where?
It isn't available.
Do you ever take a thermal image of your own wall cells? 60 seems very high. Do you have temperature regulation on your own cells?
At least every two weeks I go over all my cells. And yes 60 is high due to heat buildup.
Keep it up HB! You're the best! I did expect those fuses to all blow out... About these nickel fused plates, until now, it's a no-no for me :)
Fuses work in a way they were designed for - and it's not like this !!! I'm very happy to use them in my setup
now that you have been using the kweld for a while what do you think about it? better or worse than a Chinese welder?
The thing is a BEAST! loving it still
السلام عليكم
Iam from iraq. Iam one of your followers. I want mppsolar inverter hybrid 5kw. how i can get it because it not find in my country
The problem is the low voltage pack. There not enough potential to overcome the rising resistance of the wire so it turns into a heater wire.
Yep, dumb test but very fun to mess around with. WAS not the correct fault state.
@@HBPowerwall I just finished a 85AH 24v battery using these sheets. I really don't think this is a good way to fuse these. The fuse strip as shown in your video is not a good fuse. There's not enough of a bottleneck for current, the entire strip will just sit there and glow. Imagine your bms failing and shorting your pack with enough current to make these glow orange. You basically would have several KW of resistive elements glowing orange 1mm away from the insulator, quickly melting the insulator on the top of the cell, Then the fuse slumps across it ect and shorts the cell. I like the efficiency of it but I don't think its a proper fuse. It also seems very rare for a cell to fail in a way that would consume enough power to blow this fuse. Id imagine a cell that's got a few amp internal discharge would not blow this fuse but still be consuming enough power to go into runaway.
Another thing to keep in mind with these is safety on install. I was laying a 3p sheet down and one of the fuse pad things slipped right into an 18650 and shorted, melting the insulation ring and shit. Had to pull apart the pack to get that cell out. Took me a minute to figure out how I created a short circuit! That was VERY easy to do accidentally.
How is the rust on them? I was told they were nickel and steel. Don't want my packs rusting as they'll be exposed to weather.
Dont think i would be wanting my cells in the weather :( I think damage to cells would come before damage to nickel
Simple.. if the fuse is 8 amp x 20 it’s now a 80 amp fuse ☝️and you used them on both sides.. so 2x80 amps is 160amps .. you turned that pack into a heater .
I would expect a direct short to pop all the fuses instantly. Anything else, like creating heat coils we saw, would be too dangerous for the batteries. Think I'll just stick with fuse wires.
if the battery larger, with a PROPER direct short & the fuses, wires, busbars were the correct size for the application I would agree.. this was just a fun hack test.
They are good for 8 amps a piece so your 20p pack can hold 160amps without breaking.
Yep, and the nickel just wicks away the heat very effectively also. This is not how they are designed to blow. If only one cell goes bad the fuse vaporises
Any fuse is going to blow much higher than its rated for when burst.
You need to do CONTINUOUS people!
Thats how i believe it works
That 144 amp was due to the fact your alligator clamp dropped and touched the actual metal plate after it blew the fuse. It wasn't 144 amps thru that fuse lol..
perhaps... wasn't really good science but it was a heap of fun ..
....the bloody solder started melting on that last test.
Lots of stuff melted - I still have that battery in a box outside and at least 15 still have a good charge - rest CID has poped
i dont think that amount of peak current can output a single 18650 cell?
Probably not an ideal test given how hot how fast they got :P
144 amps was when the alligator shorted out on the nickel sheet
Perhaps
Good test, better you than me
Someone has to go to the moon first :P
Send some to Joe he has the high dollar fuse checker that works purdy good
JOE would you like to do that?
@@HBPowerwall I got a sample in the mails and will get on it!!!
It is a HIGH dollar piece of equipment😆💥
It would be cool to do a test on a 100amp draw on like 80p, see how the discharge goes. I guess you 30amp on 20p is comparable.
How thick is that nickel? I did a few napkin calcs and I worked out that if the nickel between the cells is 10mm and you are allowing a 5 cell wide pack and if the nickel is 0.2mm you would only be able to run 20a continuously at 60°.
So your 30a at 65° is probably pretty close, does look like you either need thinker nickel or solder some bus bars for larger currents like 100a.
Get Joe to test it! He know the way around fuses :D
I got a sample and will be doing some testys!😆🤘💥
Can't wait joe!
These nickel fuses are great but can’t see them being cheaper than 1a fuse wire.
There is a cost in the time it takes and the look of the finished product
You absolutely shuld use need a bench top power supply to test fuses.
If you insist of doing it like this with batteries instead of a power supply or electronic load you need a >10MHz oscilloscope across a shunt or a magnetic oscilloscope probe to catch the flank, not a crappy magnetic clamp meter' max hold.
you should check out some of my older videos about cell fuses - this will make you eith smile or laugh lol 1. th-cam.com/video/RAfMq_EZ4oA/w-d-xo.html 2. th-cam.com/video/5hiQCD8LPcs/w-d-xo.html
OOh this is the one i was hunting for - th-cam.com/video/eX6uIz_iflA/w-d-xo.html talkabout basic tests
@@HBPowerwall I like that old video. You showed that the fuse doesn't burn.
By the way every fuse worth it's salt should come with a sheet like this: www.swe-check.com.au/images/content/time_current_curves.gif
So for example the fuse rated for 250mA will burn in 1 second when it sees 1 amp, but it will burn in 0.1 second if it sees 2.1 amps.
You just follow the curve what it is rated for and read the seconds it will burn in for which current.
Cell replacement could be easy if you use mini magnets instead of spot welding. BTW, I would not fool around with extreme currents inside the house; exploding battery packs are not a joke.
It's my workshop and accept those implications
for that reason its best to put mini juses on wire with zip tie @@
18:00 what you're actually surprised that the whole pack on one fuse blows it, but distributed to many fuses it doesn't? I don't understand.
yeh done poorly but still fun - and I enjoyed the messing around land learnt something so... BIG win for me
@@HBPowerwall I bet. Thanks for the videos! Really enjoy your content!
Thanks for tuning in :)
I'm going to guess that the reason they didn't blow in the small pack was because there is enough nickel there to dissipate the heat fast enough to keep them from blowing. On the larger pack, there's too much current for the plate portion to absorb the heat.
And yeah, I'd say that one cell is toast 😜
Electrical tape adhesive degrades into a gooey mess with little adhesion.
Wasn't a good choice thats for sure!
You need a current shunt and a oscilloscope to get a good result in your test or find sombody in your area for help.
I would love someone in the community to hit me up so i can learn how to do these tests right and with a little more consistancy! Much to learn still...
@@HBPowerwall Hi mister! Go to EBay search for 500amp shunt you should see one for $29.16au. You can use that with a scope or a good multimeter with min and max. It puts out 50mv @ 500amps so at 500 amps it would show 50mv and 100 amp show 10mv and so on.
thank you peet you test was great
Thanks Barry
14A-144A each cell is really high current.. and lets face it _ there are really not many case where cells short like that _ and each pack having 100 cell _ will ned 150A to 1500A _ thats insane _
Yeh, it's more when all the cells dump their power into one faulty cell.. fuse will vaporise then.
No fuses will take so much time even after a short circuit check out Tesla fuses how fast they blow if the cells are shorted . I feel this design is complete disaster.
to be fair this isn't a very good test at all doing the whole pack short with a cable that's too small. all fuses blow at their rated capacity - it's hard to know if i was exceeding that. it was a shit test but I did enjoy it
@@HBPowerwall there is a design flaw in this fuses . Fuse getting red hot but not blowing is a flaw from my knowledge this fuse should have some physical stress so that when the mechanical strength goes down the fuse disattach from the battery so it fuses out in the perfect current load
Brother, Safety first
Nar have fun .....
That fuse pack will start a fire before its doing any good...
To be fair it's not the correct fault state for the fuses - just a bit of messing around.
@@HBPowerwall true, but in a normal use the drain is usually not constant, and how long does it take for the fuse to break? :)
If its too long it can start burning:/
@@williamwestonn these fuses are not a security for a shorted pack. these fuses are for shorted cells.You got some serious problems if you whole pack is shorted. Tell me how you want to short a whole pack?
put fuse only on one side. it will blow faster.
Yep
Need a adjustable power supply for a more accurate test.
Still very interesting.
Its was defiantly not a controlled environment but it was fun messing with it.
It should be tested fuse per cell not 1 fuse in paraller of bunch 18650
Yes, i did that in the last video i thinks
2:42 I'm blind
I didn't take my shirt off in public again did I?
@@HBPowerwall Not this time, otherwise my eyeballs would have bursted into flames hehehe
You said "You can see heah somweh" but I can't see what are you point at :)
lithium + water : nope !
Water is to halt the thermal run away to other cells not put it out. Ask any fire department how they deal with an EV fire... Water & HOURS AND HOURS of it!
@@HBPowerwall agree. Probably the only thing that kept one my one thermal cell from catching fire was cooling it in a cup of ice water. There's no stopping an internal short, but if you get rid of the heat as fast as it's making it, it should be ok.
vaneay vaneay there’s no metallic lithium in a rechargeable li-ion battery. Water is no problem and is the recommended method, along with aqueous firefighting liquids/foams, for fighting secondary Li-ion fires. Only non-rechargeable “primary” li-ion batteries have metallic lithium in them which can be a problem is the battery is opened up.
Those fumes are toxic by the way.
DAM too late now...
showw perfect
Thank-You....i think...