I like the disclaimer. More folks should do that. To many people setting things on fire and blaming everyone but themselves. Also interesting cells, I will have to look for some.
Maybe for safety reasons you should mention that if someone wanted to use additional flux for the soldering, they must under no circumstances use flux that contains organic acids of any kind. I've come across so many people who think flux = flux, what's the difference? And then they end up with some acid corroding through their electronics, or even worse, through their batteries. Make sure that all flux is rated for electronics use, the strongest you should use is ROM1 type flux, but even that should be brushed off with IPA after soldering (it might re-activate in humid and warm conditions and start corroding stuff, although not nearly as badly as acid flux). The safest flux to use in these types of projects would be a mild REM0 no-clean flux intended for smd electronics.
Just wondering about the battery options. You have shown using 18650 grid holders with nickel strips with shrink wrap, jahu garcia uses pcb to hold batteries, and will prowse uses the larger lithium cells. All are good and work. Pros and cons?
Could you do a tear down and possible replacement cells video on a Bosch 625 wh ebike battery. Not a single video on it and loads of people with worn out cells, would be good to see if you think you could replace cells, maybe even increase capacity with good quality cells
Hi..! Hope you have a great day. Please guide me if I want to build same like this a 4s 6p 21700 battery pack will be it is suitable for laptop power bank..? I have HP ProBook 430 g2 laptop which requires 14.8v and approximate 2A Please reply I'm waiting for your kind guidance. Regards: M.Zubair
Could you use these cells to build some 14s14p packs to charge a Bluetti AC200 or something similar? Maybe build 2 or 3 of them, and connect them in parallel then to the unit?
Great video!! Couple of questions: You have a BMS, why do you need a balance lead to charge? Also, you soldered the charge positive directly to the positive terminal, why not to the P- on the BMS board and then solder a wire between the B+ and positive terminal?
Great video. I really enjoy your work and the way you present and explain everything. How much does that battery weigh? Thanks and keep up the great work.
Thanks, I enjoy your thorough explanation and videography! Would you please provide a source link for the large blue heat shrink packaging material. Thanks again.
I’m confused with the bms wiring...when searching that 4S bms diagram shows using P+ P- and B+ B-. Yours only uses B- and P-. Will that be the case for any bms?
In the case of this particular BMS, the P+, B+n and red positive wire are all connected together on the board. The negative is the only pole being switched. The BMS was designed to fit on the side of an 18650 battery pack, where you would bend over the nickel strips to sit on those pads. That's why the pads are in each corner they way they are. Since we are connecting with the balance wire connecter instead, there's no reason to connect the P+ or B+. You could if you wanted, but don't have to.
I've got a Model 3 battery module I'm disassembling and building a couple 100 Ah, 24 V packs, some 48V 14s2p ebike packs and a few little 12V packs to power misc. projects. Thank for the informative video. Any way I could get the honeycomb 21700 cell holders?
Cool, wish I could get my hands on a complete module. That would be a fun tear-down! The holders should be available soon. I just checked with Keith, the person who owns that eBay store, and he said maybe end of the week. The batch he got in was defective, (oversized by 1mm) which is why they look a bit loose in my video, and is waiting for the replacement shipment.
I got my Model 3 module on ebay from a company in Rancho Cordova near Sacramento, CA for a very reasonable price. The module was from a car with less than 30k miles and the cells are measuring close to 5 Ah. The teardown is a PITA. The glue is strong and there is a fair a amount of fiberglass reinforcement. If you had use for a 23s pack it would be great as is. I ordered the cell spacers. They look like the ticket! Thank you for the info.
Could you tell me how to conduct discharge / charge of Lithium ion battery experiment and log every 1 second. And using the experiment I can calculate SOC and SOH of the Battery. Please give me any clue how I can log (the devices that I can use). Thanks
LOL. I put that side up as it was the smoother of the two sides. I really need to get something to put over it as a better surface to work on, just not sure what to use.
What if I want to make a 36volt battery at 10 or 20 amp hours what kind of bms do I need for it and what kind of charger do I need I have a swagtron electric bike it only has a 36 volt 4 amp hour battery the charger is 42 volts at 1.5 amps do I need a 42 volt charger with higher amps how much will the battery’s cost to make that I am getting a new electric bike that I can go 230 miles on a charge that cost about $6,000 but they say it’s going to take awhile to get it
I used the LiPo setting (lithium polymer) because it is pre-configured to stop charging at 4.20V where as the Li-Ion is pre-configured to stop at 4.10V. You can edit these, I just haven't bothered as it's easier just to click the LiPo option.
Too bad, it doesn't ship here. I kinda wish that there was someone in Europe to supply these. Or any kind of recycled cells. I was surprised, because I thought that these were from batteryhookup.
LithiumSolar 073120/1210pst. Please no need to be perturbed by the slip of words, typos and mistakes. Show me one single person who has not erred. To be honest, I have spoken at an audience “Telsa”, inadvertently. I was not corrected by those eminent scientists and researchers. It is called understanding, it is called judgement. We all make many mistakes in life and it’s out of those mistakes, we correct ourselves and that’s called ‘experience’ . Sir, go on, do your relentless service to humanity, we care. You are one of a kind. We need you. Stay safe and 73s..
Thanks for the video. This is super helpful. I am building a battery pack for an efoil board. 52V, 70AH with a peak draw of 200A. It will be a 14S and 14P using 21700 cells. I was wondering if you have come across a nickel plate with fuse for individual cells.
Nickel is the standard with spot-welded batteries. You can certainly use copper, which has better conductivity, but you won't be able to spot-weld it without some very expensive equipment :)
A bit confused... are these straight Lithium or Lithium/iron/phosphate (LiFePo4)? What was your final cost for all materials? I am an Amateur Radio operator, & I am looking to build/buy a 30AH lifepo4 for my portable Ham equipment in the near future. My equipment nominal voltage is 13.8 vdc +/- 15% @ max 25 Amps.
They are 3.7V lithium. If you're looking for a 12V replacement, LiFePO4 would better suited for your needs. The voltages of 3.7V cells doesn't work out well for 12V applications as it ends up being too high or too low.
After watching a number of videos on making battery packs the issue of fusing individual cells has come up. It looks like a major PITA to fuse each cell. What do you thing about doing this?
You can stick your hand across those conductors. You can do so all the way up to about 70v- that's where you'll begin to get shocked. Not even my 50.4v battery can shock me.
@@LithiumSolar Sweaty hands? I don't know. I know some people have a higher salt content on the surface of their skin, so who knows. I just built a 12s10p 18650 pack, and I might have felt a tickle or two. There's no need to treat it any different than a 12v battery. You can handle it, you can put both hands on those conductors all day long.
that's funny because i started with li-ion because i wanted to play 12h of pokemon go (have done 24h too) li-ion was one of 3 things i didn't want to touch, li-ion (fire), hv (death), lasers (retina damage) but it was only option now i have way too much of 18650 cells and fallen pokemon go interest but of course i don't stop. as portable packs became boring as they just don't ever run out, i'll be building house(s) backup power next, following the electric bicycle probably and then maybe a car it's fun!
I noticed what you refer to as a "cell" is actually 6 NCR21700 connected in parallel. I found this terminology a bit odd. But hey if it works for you then it's all good.
Yeah I really don't know what that was about, but I didn't want to look deceptive by cutting it out. All I did was unplug and replug and it worked fine after. No idea.
careful where you are putting the knife around the plus end of the cell if you was to short the cell bad things can happen. a suggestion: in future videos you may want to use some non conductive when ever pointing at the top of a cell.
if they was pulled from a faulty pack then they should have sharp points from where they was welded to and then the bus wiring was removed. even if you dremel down the sharp points there would be evidence of salvaging. unless they are playing it safe and they dont want the same lot numbered cells being used in newer revision bms packs be very carefull poking anything metal on the positive end of a battery cell if you was to touch the + and - together you would have a short and bad things can happen. you should use plastic pointer instead. a single cell you may get a spark and destablize the cell if shorted but a large battery pack big sparks., fire and blinding light and molten metal.
@@LithiumSolar could you help me navigate the ins and outs of purchasing a spot welder. I seen cheap ones and wonder if they are just junk and a waste of time and money. Any input would be much appreciated. If you have a moment. Thanks.
for a good high-current load, just use a long spool of very thin magnet wire, (unspooled, of course) into a plastic tub of water. it's amazing how much current and time it takes to heat up water this way. You could probably dump 40-60A into that wire for 18 hours before you had to change the water, depending on how big of a plastic tub you use. ua-cam.com/video/WECW88rJYrE/v-deo.html
Hello, do you have an email address? I have a few questions regarding my own project I am dreaming up and would love some input on any recommended components. Additionally, do you build custom packs for purchase or would you consider it? I have a unique circumstance that may interest you. Thanks, -Matt
You need to work with UA-camr, #StyroPyro Your guys brains belong together. You guys would make the most amazing invention since the creation of the Ipod. Who cares about who paid what.. and make millions in views alone!
I prefer to use the pedal so I have control over when the weld happens. I don't like the weld-on-touch and yes I know you can configure a delay for it, but still... I want the control of it.
It's great that you want people to sub, but what will you do for that sub. I'm I the only one that thinks that when someone Subs, that those channels should also sub those others. If not that's fine, But we will not sub any longer.
You should only subscribe to things you're interested in. If you're not interested in the videos I'm putting out, by all means, feel free to NOT subscribe :)
The 5th digit is its shape. So the 0 means a cylindrical cell.
yup prismatic or pouch cells use 3 groups of 2 digits
Great to know, thank you!
Hey- Actually 5th digit (0) is a zero. 700 mm = length of the cell. 21700 = 21mm x 700mm
@@Chris-lp2dk 700mm is wrong. That’s 70cm so nearly a full meter
As an rc car hobbyist I will tell you this battery is a thing if beauty. 4s battery with 30000 mah. That would run my cars all day
Soldering Iron looks great. As always an enjoyable video.
These packs would make a great power wheels car battery replacement!.
Superb way of explaining. Thank you so much from India.
I like the disclaimer. More folks should do that. To many people setting things on fire and blaming everyone but themselves. Also interesting cells, I will have to look for some.
Maybe for safety reasons you should mention that if someone wanted to use additional flux for the soldering, they must under no circumstances use flux that contains organic acids of any kind.
I've come across so many people who think flux = flux, what's the difference? And then they end up with some acid corroding through their electronics, or even worse, through their batteries.
Make sure that all flux is rated for electronics use, the strongest you should use is ROM1 type flux, but even that should be brushed off with IPA after soldering (it might re-activate in humid and warm conditions and start corroding stuff, although not nearly as badly as acid flux).
The safest flux to use in these types of projects would be a mild REM0 no-clean flux intended for smd electronics.
Just wondering about the battery options. You have shown using 18650 grid holders with nickel strips with shrink wrap, jahu garcia uses pcb to hold batteries, and will prowse uses the larger lithium cells. All are good and work. Pros and cons?
Could you do a tear down and possible replacement cells video on a Bosch 625 wh ebike battery. Not a single video on it and loads of people with worn out cells, would be good to see if you think you could replace cells, maybe even increase capacity with good quality cells
could u also teach how do u change the weld pen for the sunkko? it looks really neat
He just took the unit apart, and attached them to the contacts.
Hi..!
Hope you have a great day.
Please guide me if I want to build same like this a 4s 6p 21700 battery pack will be it is suitable for laptop power bank..?
I have HP ProBook 430 g2 laptop which requires 14.8v and approximate 2A
Please reply I'm waiting for your kind guidance.
Regards: M.Zubair
Any idea what material is the button added to the tesla positive pole?
@LithiumSolar the zero at the end of batteries like 18650 or 21700 indicates the shape of the batteries, 0 means cylindrical. 1:00
Please share your view on spot welding with nickel strip vs soldering with fuses to a bus bar. Thanks.
Do a discharge test to see if it is 5000maH per cell
18 65 0 means 18 x 65 mm and the last 0 stands for round shape. Same for 21 70 0.
Thanks! This is why I love doing these kinds of videos. I always end up learning something new.
Could you use these cells to build some 14s14p packs to charge a Bluetti AC200 or something similar? Maybe build 2 or 3 of them, and connect them in parallel then to the unit?
073020/1153 pst. Thanks again for this educational/ instructional video. Stay safe and 73s..
Great video!! Couple of questions: You have a BMS, why do you need a balance lead to charge? Also, you soldered the charge positive directly to the positive terminal, why not to the P- on the BMS board and then solder a wire between the B+ and positive terminal?
Nothing like building your own tools for a project.
Please test the 21700 model 3 cell individually.it would be really helpful
0:50... It s called diameter on a round cell....
Thank you for your feedback...
Any idea on when the 21700 honeycomb cell holders will be available again?
I asked and was told they're sold out, but more are on the way and to check back in about 2 weeks. They sure sold out fast... lol
@@LithiumSolar I just DM'd him on FB, will let y'all know if I get any more details on the ETA.
Great video. I really enjoy your work and the way you present and explain everything. How much does that battery weigh? Thanks and keep up the great work.
Your videos have good knowledge keep it up 👍👍
Thanks, I enjoy your thorough explanation and videography! Would you please provide a source link for the large blue heat shrink packaging material. Thanks again.
Thanks! I purchased the large blue heat shrink from ebay.to/2WIjKNF
@@LithiumSolar Thanks Much!
Very cool. Thanks for the demo!
Thankyou a lot brother.... I tried a lot of videos but u defined it well... 💕
I’m confused with the bms wiring...when searching that 4S bms diagram shows using P+ P- and B+ B-. Yours only uses B- and P-. Will that be the case for any bms?
In the case of this particular BMS, the P+, B+n and red positive wire are all connected together on the board. The negative is the only pole being switched. The BMS was designed to fit on the side of an 18650 battery pack, where you would bend over the nickel strips to sit on those pads. That's why the pads are in each corner they way they are. Since we are connecting with the balance wire connecter instead, there's no reason to connect the P+ or B+. You could if you wanted, but don't have to.
I've got a Model 3 battery module I'm disassembling and building a couple 100 Ah, 24 V packs, some 48V 14s2p ebike packs and a few little 12V packs to power misc. projects. Thank for the informative video.
Any way I could get the honeycomb 21700 cell holders?
Cool, wish I could get my hands on a complete module. That would be a fun tear-down! The holders should be available soon. I just checked with Keith, the person who owns that eBay store, and he said maybe end of the week. The batch he got in was defective, (oversized by 1mm) which is why they look a bit loose in my video, and is waiting for the replacement shipment.
The holders are listed now ebay.to/31f4mc5
I got my Model 3 module on ebay from a company in Rancho Cordova near Sacramento, CA for a very reasonable price. The module was from a car with less than 30k miles and the cells are measuring close to 5 Ah.
The teardown is a PITA. The glue is strong and there is a fair a amount of fiberglass reinforcement. If you had use for a 23s pack it would be great as is.
I ordered the cell spacers. They look like the ticket! Thank you for the info.
nice and simple battery. i guess the nickel strip is acting also as a fuse between each cell?
No. There are no fuses between the cells. There are only 6 in each parallel grouping - no reason for fuses.
0 at the end means it is cylindrical form factor
Where can I get some of these to buy
Could you tell me how to conduct discharge / charge of Lithium ion battery experiment and log every 1 second. And using the experiment I can calculate SOC and SOH of the Battery. Please give me any clue how I can log (the devices that I can use). Thanks
4s6p battery is nice
can the two of the 4s6p battery be connerted in parallel
Make a custom Charge/Discharge Profile and you can set it up to whatever voltages you want!
Thanks! I really need to spend some time figuring it out lol
These make great Xmas gifts. How can I get on the list?
Nice and helpful video. Where did you source the extra balance leads?
Thanks! The extra balance leads were these amzn.to/3jcYAzC You really made me hunt for the order, I purchased them all the way back in 2016 LOL
pretty sure the extra 0 means its cylindrical
Ah good to know, thanks!
Bro your really fucking things up right now.... That wood clearly says this side down.... Good job dudeski.
LOL. I put that side up as it was the smoother of the two sides. I really need to get something to put over it as a better surface to work on, just not sure what to use.
thank you for this video it is well explained and I really learned a lot
very nice details. Thank you.
Really wanna get those cell holders. No link for them yet?
I'll add it when they're available. I explained in more detail on Facebook :)
BigBattery is including FREE cell holders with each purchase!
What if I want to make a 36volt battery at 10 or 20 amp hours what kind of bms do I need for it and what kind of charger do I need I have a swagtron electric bike it only has a 36 volt 4 amp hour battery the charger is 42 volts at 1.5 amps do I need a 42 volt charger with higher amps how much will the battery’s cost to make that I am getting a new electric bike that I can go 230 miles on a charge that cost about $6,000 but they say it’s going to take awhile to get it
Thanks for another great video
Has anyone seen hexagonal holders for 32xxx cells?
Why did you use the LiFePO4 setting on the charger?
I used the LiPo setting (lithium polymer) because it is pre-configured to stop charging at 4.20V where as the Li-Ion is pre-configured to stop at 4.10V. You can edit these, I just haven't bothered as it's easier just to click the LiPo option.
@@LithiumSolar I'm glad I am not the only one doing this! ;)
I cant recall, but didnt you create a pack with individually fused cells with lead wires? I'd like to review that again.
Could you visit Corridor Cast some time ?
Too bad, it doesn't ship here. I kinda wish that there was someone in Europe to supply these. Or any kind of recycled cells.
I was surprised, because I thought that these were from batteryhookup.
Why does the Title say Telsa?
These cells are from Tesla Model 3 electric vehicle batteries.
@@LithiumSolar Telsa != Tesla :-)
OOOOO crap. Thanks!
@@LithiumSolar Dylsexics of the world untie, you have nothing to lose but your brians! :-)
LithiumSolar 073120/1210pst. Please no need to be perturbed by the slip of words, typos and mistakes. Show me one single person who has not erred. To be honest, I have spoken at an audience “Telsa”, inadvertently. I was not corrected by those eminent scientists and researchers. It is called understanding, it is called judgement.
We all make many mistakes in life and it’s out of those mistakes, we correct ourselves and that’s called ‘experience’ .
Sir, go on, do your relentless service to humanity, we care. You are one of a kind. We need you. Stay safe and 73s..
Thanks for the video. This is super helpful. I am building a battery pack for an efoil board. 52V, 70AH with a peak draw of 200A. It will be a 14S and 14P using 21700 cells. I was wondering if you have come across a nickel plate with fuse for individual cells.
Awesome video as always 🙂👍
Why do you use nickel ? and can copper be used as well ?
im not very experienced sorry for the dumb question :P
Nickel is the standard with spot-welded batteries. You can certainly use copper, which has better conductivity, but you won't be able to spot-weld it without some very expensive equipment :)
@@LithiumSolar Ah ok, thank you so much!
🤔 U got the big battery link have..?
I don't think they've sold these cells in a couple of years now.
A bit confused... are these straight Lithium or Lithium/iron/phosphate (LiFePo4)?
What was your final cost for all materials?
I am an Amateur Radio operator, & I am looking to build/buy a 30AH lifepo4 for my portable Ham equipment in the near future.
My equipment nominal voltage is 13.8 vdc +/- 15% @ max 25 Amps.
They are 3.7V lithium. If you're looking for a 12V replacement, LiFePO4 would better suited for your needs. The voltages of 3.7V cells doesn't work out well for 12V applications as it ends up being too high or too low.
@@LithiumSolar thanks...
2:15 that's also supposed to be the E from the Tesla logo
After watching a number of videos on making battery packs the issue of fusing individual cells has come up. It looks like a major PITA to fuse each cell. What do you thing about doing this?
Where do you get the BMS boards?
This is the BMS amzn.to/3jY3gdB I'll add it to the description
@@LithiumSolar Thanks!
You can stick your hand across those conductors. You can do so all the way up to about 70v- that's where you'll begin to get shocked. Not even my 50.4v battery can shock me.
It depends on a lot of factors. I can feel 24V from a 7s battery...
@@LithiumSolar Sweaty hands? I don't know. I know some people have a higher salt content on the surface of their skin, so who knows.
I just built a 12s10p 18650 pack, and I might have felt a tickle or two. There's no need to treat it any different than a 12v battery. You can handle it, you can put both hands on those conductors all day long.
The last digit is the shape 0 for a round cell..
which spot welder did you use?
Sunkko 709AD, 240V Model
How many hrs of pokemon go would that last you for?
that's funny because i started with li-ion because i wanted to play 12h of pokemon go (have done 24h too)
li-ion was one of 3 things i didn't want to touch, li-ion (fire), hv (death), lasers (retina damage) but it was only option
now i have way too much of 18650 cells and fallen pokemon go interest but of course i don't stop. as portable packs became boring as they just don't ever run out, i'll be building house(s) backup power next, following the electric bicycle probably and then maybe a car
it's fun!
Thank you, sir.
I noticed what you refer to as a "cell" is actually 6 NCR21700 connected in parallel.
I found this terminology a bit odd. But hey if it works for you then it's all good.
Yes. If you want to be technical, when you connect two cells it becomes a "battery"
error 3211? a5? watchdog error?
Yeah I really don't know what that was about, but I didn't want to look deceptive by cutting it out. All I did was unplug and replug and it worked fine after. No idea.
I'd buy the pack you built here, if you're willing to sell it
I don't sell batteries unfortunately.
Those cells are good :)
careful where you are putting the knife around the plus end of the cell if you was to short the cell bad things can happen.
a suggestion: in future videos you may want to use some non conductive when ever pointing at the top of a cell.
if they was pulled from a faulty pack then they should have sharp points from where they was welded to and then the bus wiring was removed. even if you dremel down the sharp points there would be evidence of salvaging.
unless they are playing it safe and they dont want the same lot numbered cells being used in newer revision bms packs
be very carefull poking anything metal on the positive end of a battery cell if you was to touch the + and - together you would have a short and bad things can happen.
you should use plastic pointer instead.
a single cell you may get a spark and destablize the cell if shorted but a large battery pack big sparks., fire and blinding light and molten metal.
You can see how we demanufacture these model 3 cells form its original pack to the individual cell here: ua-cam.com/video/ckhjYMAE9yg/v-deo.html
since batterhockup sells them for 2,49 big battery also does a sale )-:
Yes, it seems a price war has begun lol. That just means cheaper prices for us! :)
You sure know a lot of battery charging tricks.
It's a fun hobby, I'm constantly learning something new every day :)
@@LithiumSolar could you help me navigate the ins and outs of purchasing a spot welder. I seen cheap ones and wonder if they are just junk and a waste of time and money. Any input would be much appreciated. If you have a moment. Thanks.
DeltaV you say.. KSP explosions INTENSIFY
for a good high-current load, just use a long spool of very thin magnet wire, (unspooled, of course) into a plastic tub of water. it's amazing how much current and time it takes to heat up water this way. You could probably dump 40-60A into that wire for 18 hours before you had to change the water, depending on how big of a plastic tub you use. ua-cam.com/video/WECW88rJYrE/v-deo.html
You were almost better off just buying a couple 3S LiPO packs from an RC hobby shop
Maybe. I enjoy the hobby of making my own though.
@@LithiumSolar same here honestly. I did something similar for my kids powerwheel
Hello, do you have an email address? I have a few questions regarding my own project I am dreaming up and would love some input on any recommended components. Additionally, do you build custom packs for purchase or would you consider it? I have a unique circumstance that may interest you. Thanks, -Matt
Please make a video of you trying to take this battery through airport security
No thanks. I'd prefer NOT spending a night in prison while they sort it out... LOL
@@LithiumSolar lol
I'd change the thumbnail image to something less Homeland Security attracting 😂
I would welcome Homeland Security to come check my BATTERIES at any time ;)
the cells have diameter, not thickness
Thank you for that correction :)
You need to work with UA-camr, #StyroPyro Your guys brains belong together. You guys would make the most amazing invention since the creation of the Ipod. Who cares about who paid what.. and make millions in views alone!
I see you guys making worlds most powerful self charging laser. IE Free Electricity and Power.
😁✌🖖👌👍😎very cool
I got these from battery hookup $2.49 each
Yes, it seems the competition has driven the price down quite a bit since this video lol
damn Tesla spot welder makes a "Model ///" shape .. Elon is crazy ~_~
It’s actually Panasonic 😅
Why dont use a Kweld? You can be much more productive.
How is the kWeld more productive than the spot-welder I have currently? It works great...
@@LithiumSolar You can set in the settings that as soon as you touch the nickel with both electrodes, it automaticly activates the spot-weldig proces.
I prefer to use the pedal so I have control over when the weld happens. I don't like the weld-on-touch and yes I know you can configure a delay for it, but still... I want the control of it.
@@LithiumSolar Yes thats personal. But ive you only got a limited time budget, its preatty helpful
It's great that you want people to sub, but what will you do for that sub. I'm I the only one that thinks that when someone Subs, that those channels should also sub those others. If not that's fine, But we will not sub any longer.
You should only subscribe to things you're interested in. If you're not interested in the videos I'm putting out, by all means, feel free to NOT subscribe :)