DeWalt 20v Max Lithium Battery Rebuild - Mikes Inventions

mikesinventions.etsy.com paltap.me/MikesInventions
DeWalt 20v Max Lithium Battery Rebuild is exactly that. I show you every step along the way, and a few potential stumbling blocks. I replace the cells with newer, better Samsung 18650 cells from 18650batterystore.com. Alex and I build a lot of battery packs now with our new spot welder from Banggood. We love this little guy and we're always finding packs that need building. My DeWalt packs are now better than before. They are now 3AH instead of 2, and I rebuilt each one for about 25% the price of a new one. It was a lot of fun too! Check it out.

[@dogukancil5128]

Those batteries you tried to put in there are protected cells. They each have a protection circuit on top called a BMS, for battery management system. That's why they are slightly longer and have a knob on top and also why they don't fit into your battery pack. Since your Dewalt battery pack has a BMS of its own, they are really not necessary. They add extra resistance, parasitic loss, limit the current and worst of all, they glitch out and cut the power on really high loads, because high loads will momentarily lower the voltage below the threshold voltage, which is usually around 3V. You can actually very easily remove the protection circuitry if you remove the shrink wrap on those batteries. They are connected by a nickel strip. They are not really designed for high power applications like a power tool. Flashlights infamously do not include a BMS, that is why they are mostly used in those applications and plus the knob on top makes it easier for regular folk to locate the positive.

[@M40A5]

Awesome information to have, thanks for sharing!

[@pawekuzniak7807]

😊

[@chuckinman2798]

I took apart a 4 AH battery and instead of cutting the terminals on the bad cells I used a drummel tool to cut through the spot welds and I have enough of the terminals left to attach them back to the new batteries.I also marked them + and - to insure that the new batteries are put back properly oriented. Doing it that way I only have to solder, or spot weld, the terminals onto the new cells.

[@joncamp9126]

I was thinking the same thing, I’ve popped the welds up with a pocket flathead easy. Less work is the way I always intend to work, and it doubles as the smartest way more often then not.

[@wagu7003]

Dremel. Good tip btw

[@johnrhodes3350]

Those Samsung 30Q were ideal for your needs. Good Capacity, Adequate power delivery, and great value for money.

[@GutsyGibbon]

Well, you inspired me. I had a bad Black and Decker tool battery and decided to rebuild it. I bought the little welder and a set of new 18650's as you did. Big surprise! When I went inside to start desoldering the wires, I found a sense wire that had broken. I resoldered it, and the main positive and negative leads that I had already desoldered. I put the battery back together and it is working just fine. I guess the welder and spare 18650 will have to wait until another of my batteries fail.

[@homeandbackyard9599]

Never know and see a spot welder like that. That really impressed me! Thanks Mike.

[@wagu7003]

You know you're a bit of a tech nerd when he says "this is really exciting let's get going" and you agree.

[@JohnClutch1]

Ive said "perfect timing" many times in life, but this video tops them all on perfect timing!!!! Thank you

[@Ken3t69]

K0

[@TheBootyWrangler]

One time I cut open a micro usb, stripped the pos/neg and put them to the + - on a Bauer bat and it actually worked until I forgot it like that for a whole day and it lit on fire

[@denverdanoreno]

Mike you keep it simple in a very complicated world. Thank you buddy!

[@Eremon1]

Great little spot welder. Haven't seen such a neat and compact unit like that one.

[@lolslim690]

Oh I know that feeling, I found a Milwaukee M12 3.0 the one with the square bottom from a recycle bin, and I already had salvaged 18650, and I repacked that m12 and use it at work.

[@kleinstruction874]

First time seeing spot weld soldering! Can't wait to try it!

[@rpeavey35]

Thank you! I picked up the spot welder and and can’t wait for it to come in!

[@RiccardoPearlman]

Killer work dude. I have a bunch of these dewalts and I even power my cameras with them. I was planning on having to do this down the line, and it's great to see that the battery controller tolerates cell replacement- and even a cell upgrade! Those Samsung 18650's are definitely the way to go.

[@malayekk6522]

I think the spot welder is the main tool to do this job right along with right type of batteries. Phenomenal work mate. Thanks for sharing.

[@Kaptainkneemow]

Nicely done. Excellent video. No fluff and clearly see what you did. Thanks

[@tomfrederick6083]

I have been playing Hell trying to get the bottom black casing separated from the battery cage on a DCB404. Now that I know it is probably RTV'd in place, I might get a little bit more aggressive with the screwsticks. Yours is the best video I have seen on actually doing something useful with these batteries. I have tried the jump-start technique to no avail, so I would like to actually measure each battery with a multimeter. Thanks for being detailed. New subscriber on board!

[@smithincanton]

I am really impressed with that spot welder! Looked at it and it's USB-C rechargeable. Really awesome. I'll have to pick one up!

[@hawkskyflier]

This has been the best "Rabbit Hole" I've went down in a long time!!! Thank you for the rebuild. AND best of all the battery welder.. before I got done watching this video I bought one! Thank you so much Mike. keep up the great VIDS!!

[@kirbycollins3223]

That Spot Welder is a Must Have For Many Types of Small Electrical Projects

[@stewartbruce2409]

Excellent tutorial Mike. No loud obnoxious music or sensationalism of any kind, rather just easy to follow, and a pleasure to watch. I would like to buy the bangood spot welder. What is the model description? Thank you for your video.

[@MikesInventions]

Hey! Banggood calls it a 1S mini spot welder. It’s the only one on the site that looks like the one in the video. There’s a flash sale on it right now.

[@stewartbruce2409]

@@MikesInventions Firstly thanks for your reply. I don't see the flash sale. Its still the same price as before approx. forty dollars and change. Sending you all the best!!

[@RinsePrince]

Thank you so much for this, Mike! Your video was the first and only one I'll be watching, no need to watch anymore - nice job! Amazon sells similar spot welders, and I will definitely be rebuilding instead of buying new one's! Peace.

[@bryancunningham1095]

Next battery pack you rebuild to get strip off grab with needle nose pliers and roll the strip off by twisting the pliers, when reassembly use new nickel strips and replace with a good quality 18650 cell of higher capacity, if your going to all the effort to rebuild the pack use better batteries that have a higher charge and discharge rating. Great video, i allways learn something new.

[@virginiaoverlander4720]

Great video. I try to make my batterys last as long as possible. Always using the slow DCB107 1.25 amp charger to keep charging temperatures low and storing them at room temps but eventually they degrade. This will be helpful.

[@KimFatica]

This was a great find...of course, the day after I purchased the new DeWalt Powerstack batteries to replace my two old DCB201 batteries. The new Powerstacks use pouch cells vs traditional cells. The Powerstacks are a more compact form factor with a slightly better power output. I have a big, clunky DCB230 (3Ah) and a DCB205 (5Ah). This tutorial should be helpful when one of those begin to choke. Thanks!

[@WaltWW]

This is most important to rebuild batteries that are no longer made like the 18v l-ion Dewalts and some bigger 56v Echo batteries I have. Thanks for a clear explanation.

[@davidbarker3591]

You do know that the 18vand 20v Dewalts are the same battery. They use the EXACT same 18650 cells. Nominal working voltage (the cell spends 85% of it discharge in this area) is 3.6-3.7v. Multiply by 5 and you have 18v. All Dewalt did was measure at close to full chhage, 4.0v, multiply by 5 =20v. It is a marketing ploy, that's it

[@bryancunningham1095]

One last note, put a little silicone on packs when reassembly so they dont jiggle around in the case, it might make one of your welds or solder joints come loose. Also trim off your nickel strips so there is no extra extending past your welds. Tell Alex he did a great job and teach him about the tools he uses and about safety and danger especially around li-ion batterys.

[@padieromel]

You're Awesome Mike..I learned something today..I wish I knew that spot welder when I was fixing my electric scooter battery..👍

[@ernestlunsford3964]

what a great informative and to the point video,please make more on lithium batteries ,you and your helper did good 5 thumbs up.

[@azadismail230]

That was an awesome demonstration, Mike. Thanks much

[@EdBlack-]

Awesome work man. I need that spot welder in my life!

[@BDL090754]

A truely excellent tutorial video, If only others could do them this well...Thanks very much Mike, ..!

[@MikesInventions]

Awww. shucks. Thanks Brad!

[@rard32093]

Great information I've been wanting to rebuild some batteries for a while and this might be my motivation to do so. You were very detailed👍 also glad to see your getting Alex Into this kind of stuff it's so important to teach kids to work on things and it's a great way to bond. And for that I liked and subscribed to your content.

[@MikesInventions]

Thanks Jerry! Welcome aboard.

[@rykson161]

Good job ! From France and I am rebuilding my own batteries

[@alanmcrae8594]

Excellent how to video! I have standardized my power tool battery packs to DeWalt 20V Max battery packs, and purchased adapters to my non-DeWalt power tools. This means that I only have to maintain one brand of battery pack and it can be used everywhere on my homestead. At some point, I'll need to open these packs and replace the 18650 batteries to keep my system running at peak capacity. Imagine if manufactures built their battery packs to make 18650 battery replacement a simple consumer diy procedure. The planned obsolescence that results in a one way trip to a landfill is a massive failure of corporate responsibility to the environment.

[@yeliab814]

I like this approach . Just keep in mind the Dewalt 20vMax lithium packs have no onboard BMS; they only have a failsafe fuse against a severe short circuit such as caused by catastrophic short circuit failure of a single tools's power electronics, or of an accidental direct shorting of the + and - output terminals. Under normal conditions the tools themselves take care of over-discharge-current protection, as well as overdischarge /low- voltage cutoff. The chargers do the overcharge protection , as well as the individual cell balancing. I like this approach because it makes the batteries more reliable because there's no BMS to fail. However, when you use them with an adapter to power a tool that expects a battery containing an integrated BMS - Ryobi for example - then you have to manually manage overdischarge protections yourself -- by either checking the on-board charge indicator and stopping at 1 bar, or else by stopping using the tool when the power has fallen-off substantially. I try to use more shallow discharges and swap packs more frequently. The packs will thank you by lasting much, much longer. So much so in fact , that you probably won't ever need to face re-cellling them.

[@Sembazuru]

Nice project. My only comment is it might have been a little easier with finer tipped needle nose pliers. I think I need to get one of those spot welders for myself.

[@andrewwilson4822]

Great video very informative thank you. I will definitely be trying this on my batteries.

[@michaelbodnar477]

Very informative and helpful to rebuild batteries.

[@RodneySolarCircuits]

so glad you got real 18650 replacement, those others would have been crap. Ive done this with cells i got from an ebike. 3.2ah cells, old new stock panasonics

[@hiepdinh4396]

I really liked you and your video !!! You explained clearly and tutorial orther well very honest no hidden tricks !!! You are one of the best youtuber I had following !!! 👍👌👏😃

[@karl3349]

Great tutorial!! I am brand new to Dewalt, but will definitely keep this video handy cor when the cells start to lose capacity. I heard the three amp cells are too large cor their rating, and like the size if the two amp cells. Rebuilding that platform to three amp capacity would be great. Thanks again. You gained a subscriber!!

[@spinnanz]

Be aware that where you have folded the nickel strip for the (+) terminal, the fold can weaken the strip and crack. Under high amps it can become a hot point and cause the strip there to fail (I had it happen myself). Its better to make an "L" shaped strip with 2 strips welded together. Also, when you weld the balance stips to the main strip, drop the welders amps/time down. as there is no cell directly under these welds to draw heat away, the welder can blow through the strips here. Good job otherwise!

[@nitaruru8331]

Thinking might want to spot weld the fold - just a thought - kia ora

[@FliesLikeABrick]

I need to do this with some of the 18v li-ion batteries that dewalt made for the older 18v tools. They make the older tools so much more usable than the ni-cd but dewalt sold these batteries for a relatively short period of time. There are the 20v adapters for 18v tools but those are pretty clunky and don't have great physical fit in some tools

[@majidsiddiqui2906]

Excellent video. will be copying your instruction. Have just purchased the contacts welder. Thank you.👍

[@chrishuerta5668]

Thank you so much Mike I can't tell you how much I appreciate you for showing me this video I saved a lot of money doing what you said thanks again and God bless

[@bignbuilds3209]

i knew i needed a battery spot welder ... and you confirmed this with your lad helping out.. : ) got some e bike and scooter battery's that i am playing with and this tool will be a great addition to the team .. great work ..

[@fullchrist4405]

Take care of this spot welder, it is not good for pure nickel .15mm and above. Nickel plated will work fine with this but under 0.15mm. To pass more ampere it is essential to have a pure nickel of .15 or .2mm.

[@andyhuynh7933]

Thanks for the video clips.

[@anthonyshorts8121]

Good job Mike, now I know how to do it! Thank you.👍

[@wayne4424]

Worked for me. Put discharged battery on the charger, red light flashed on the charger indicating a bad battery. Jumped with a fully charged battery (+ to +, - to -), waited 5 minutes. I put the bad battery on the charger and it began charging and came up to a full charge. Thanks

[@hayzersolar]

great video i been doing this for 2 years now i have a stationary spot welder and make extra money on the side.

[@lionden4]

love the welding tool!!

[@DaleScharphorn]

I love the Dewalt brand power tools... I use them on a daily basis as i am currently building 5 metal buildings. I have a couple of battery packs just like that that are dead in the water and need to be redone... thank you so much for the instructional know how.

[@capone_rd_809]

or you can warranty the battery and get a free replacement and not have to do any of this

[@brett4life2010]

Most useful video I've seen in a long time. Thank you!

[@norbithehun]

First of all, thanks for this video sharing to us and your job. Let me suggest some things: U were lucky that the first Meco 18650 4000mAh cells didn't fit to the case because your power tools wouldn't work with that battery pack. I haven't found any datasheet about that battery cell, but I am positive, that it cannot handle more than 5-8A continuously. In a power tool's 5s1p battery pack U need cells, that can handle at least 20A continuous discharge without overheating. An other thing: did U check the original nickel strip width and thickness? I am pretty sure that was more then 0.12mm.

[@Schlaegel]

Ideas: Weld the tin fold in the folded position, or it will be a breaking hazard. Sand the tin strip where you solder to it.

[@MrDexi87]

I love how dewalt use balance voltage from charger and use simple electronic inside battery , easy to rebuild later.

[@mydogworriesalot1840]

Bingo you said it :) I took apart a Ryobi fast charge it had electronics inside.youre taking a chance on a fried board.

[@somethinlike23]

I have 2 20v single layer pack like yours. One is identical inside from 2017, the other is from 2013 and have vents on the bottom and a metal heatsink glued to the bottom of the batteries. I guess they figured out they could cut costs!

[@robster7787]

Spot welder + Batteries are already hovering at about $100. So if someone plans on doing this only once, its cheaper just to get a new battery rather than go through the trouble. Otherwise, good deal if you plan on doing this regularly. A good 5 pack of flat top cells are about $50, so it’s basically 50%-70% cheaper.

[@davidbarker3591]

You can get 5 Samsung 25R cells for $18...

[@johnemmons9087]

Great video. I love these 1865’s because they are used in so many things. I just built a battery charger for these that can be charged with a mini solar panel. So these are handy and powerful if one ever loses power for a while. Thank you! Also interesting that the 5 batteries add up to 18.5 vdc. I guess 20 volts is a rounded up number!😂

[@markm0000]

If you measure V while a 20v drill is running it drops down to 12.

[@barryclark1557]

I really loved your video, thank you so much!

[@dais-nas-xaumqaib9820]

Great video. 👍 Thanks for sharing.

[@emmettturner9452]

The longer cells likely had built-in protections circuits. On that note, it’s usually only one or two cells that fail when a battery pack goes bad, so I would’ve checked the old ones for sure. One more consideration is the amp discharge capacity. Most 18650 cells can’t unload all the amps a power tool might need, so power tool battery packs often use cells with high amp output over cells with higher capacity.

[@N4HHE]

The cells with "protection" are about 1/8" longer, much longer than shown. The cells pictured simply have positive tabs for stacking in series end on end as commonly used in a flashlight.

[@yeliab814]

nice clean video/tutorial Mike. those 30Q cells are great. I used some sony VTC6 which are similarly awesome. i've noticed the factory tabs are thicker and sometimes are nickel plated copper. it's better to pull the welds carefully and re-use the tabs instead of using those thin Chinese nickel-plated steel strips. It actually makes a very big difference on high amp draw tools!

[@firstnamelastname7476]

not sure, but I don't think his welder will do any thicker than the strip it comes with (0.15). So, if limited to 0.15 would you recommend pure nickel strips, pure copper strips (if compatible?), nickel plated copper, or doubling the nickel plated steel (if feasible?).

[@firstnamelastname7476]

I'm new to all this, so if anyone else can answer pls do

[@yeliab814]

@@firstnamelastname7476 Double up is an acceptable strategy for a weld thickness limitation. Avoid steel strips; get some pure nickel amd maybe some nickel plated copper strips from Keith Tucci at his eBay store "18650ed". get some insulating washers too to protect the positive end from short circuit. finally, watch a ton of you tube videos building batteries to avoid mistakes you will otherwise risk making.

[@firstnamelastname7476]

@@yeliab814 Cheers for the tips.. Keith's store doesn't seem up anymore.. but I'll check out my local sellers here (australia)

[@firstnamelastname7476]

(hmm keith may actually be local to me, if this is him kzbin.info18650ed)

[@schmerlski]

Excellent presentation. Good info. The world is powered by 18650s.

[@jpthecut]

Hello, I did some digging about power tool batteries and it appears they usually built with batteries that have a high discharge rate capacity, like a Samsung 25R or 25S. These battery will help for a job that needs a little tork. All battery cells don't have the same purpose. These 30Q don't have a big discharge rate (15A), which is not bad at all, but nothing like a 25S that has a 25A discharge rate. They are a little more expensive. However I think it's worth the extra charge to get a powerful battery. Have you tried a challenging job with it? Thanks.

[@mehrdadmalekzadeh3517]

It was really helpful. Thank you buddy ❤️

[@jozsef0612]

Good job 👍

[@gregs3580]

I seriously recommend you double up on the tabbing as .12mm is not adequate to carry a 30 amp or greater load the batteries can deliver and the tools demand. What you do is just weld a second tab over the first. Unfortunately the welder is not capable of welding reliably any tabs thicker than .12 mm. A min of 14 gauge wire is required and if you cut identical lengths of the wire conductor in a 14 ga wire and the tabs you are using, you will find the tabs have a mass of less than half the wire. This needs to be addressed. The tool will draw almost 40 amps under load. That very thin tabbing is the weak link and prone to overheating the pack or acting as a fuse.

[@davidbarker3591]

Samsung 30q only has a CDR of 15A. Not a big hp cell

[@gregs3580]

First of all cells with a higher discharge rating should be used unless you are not going to use the pack for anything substantial. Second, 30Q should be used in parallel to satisfy need to power most tools under heavy load. If you are going to try to rebuild a pack according to those standards .12mm tabbing is not sufficient.@@davidbarker3591

[@The_Ballo]

It would be interesting to see how well it performs in a grinder

[@gkcamden9050]

Nice work. Great video.

[@MANVIRSINGH1313]

Very informative video, great point of view in entire video 👌👌👌

[@roeblue8431]

The battery store you recommend also sells the pure nickel strips in various sizes. They talk about how it's bad if they aren't really pure so seems like they are. Thank you for video.

[@davidbarker3591]

I'll bet that the strips he used were nickel plated steel. EVERY cheap spot welder sends nickel plated steel with the welder. It carries ½ the current as pure nickel.

[@JCAJCA3]

Very informative video! Very good. GOD bless. JC

[@justincase5228]

Unfortunately the ID pin of the battery pack (as converted from a resistor which is on the main circuit board of the assembly) tells the charger how many amps. So you can't just increase the amperage of the individual batteries and suddenly change a 1A into a 2A, a 2A into a 3A, etc. The resistor is marked with "80A", for example to indicate 800K ohms in the case of a 3A pack. Put an ohmmeter from ground to the ID pin and measure the resistance. The pins are marked on the outside of the DeWalt case.

[@jeffreyh3739]

Nice. Really wondered why more people don't do this. I really wanna see someone do this with the Samsung 40T or the mollicell p42a if they can get around the physical constraints between the 18650 and 21700.

[@ericklein5097]

Some Dewalt batteries have the Samsung 30T (it was an older battery) and I think now Dewalt has some that have the 40T. Would either be an 4Ah, 8Ah, 12Ah battery. I even pulled some Samsung 25R6's off a Harbor Freight brand battery. I think it was a Hercules

[@jeffreyh3739]

@@ericklein5097 that's actually pretty sweet that they use descent cells. I guess the nature of usage and expectation of quality dictates that a bit though. Surprised that the Hercules isn't using some no name cell most though. Makes me wonder if the HO red cells use some of the higher quality, high constant output current cells then

[@camreed7073]

excellent video thank you

[@roberterickson77]

Hey Mike! Thanks for the concise video. What spot welder would you recommend?

[@aquarius9909]

An other great video. Keep it up. Just wondering if there is a specific order when you connect the battery leads to the BMS? I upgraded the cells in a 12V still working but weak cordless drill battery, unfortunately does not work, yellow & red LED on the battery coming on when the trigger is pulled, than the red LED goes off & the yellow stays on. All 3 replacement cells were fully charged before upgrade. The battery powers a GREAT NECK 12V cordless drill. Is there a BMS master reset option for these batteries ?

[@scottcates]

Sweet spot welder

[@ida587]

Really well done!! Nice job and thanks for taking the time. Your son is pretty special too.

[@gilbertogonzalez8209]

Really good show

[@ericlindstrom8569]

Can you look into the latest PowerStack batteries from DeWalt see if they can be refurbished as well.

[@mckreations5160]

Its called silastic glue used in high temp sotuations also for securing electronic components to isolate them from shock and vibration. Just FYI.

[@tonykazz2779]

nice work

[@omarabmr7594]

very informative video thank you man

[@mangojassal]

Thank goodness for fast forward

[@OrlandoRodriguez-lo2vp]

Excellent! the best! Thank you.

[@flowinthrou]

Two questions, do you trust or have you measured these meco batteries. And what if we mix different batteries of the same capacity and chemistry? Do you know if we can do that?

[@jamesb8729]

I notice my warning to folks about buying this Banggood spot welder vanished, so I felt I would put it back. Mine arrived and would not take a charge, which can be expected. What is not expected was the hoops Banggood wanted me to jump through for a return. They wanted a picture of the item, the SKU, and after receiving those, they wanted a video posted on KZbin, showing the problem. I threw up my hands at that point, and bought one from somewhere else.

[@Grundewalt]

sorry I'm late, can you pinpoint the source ? I'd rather buy somewhere else than Bangood..

[@davidbarker3591]

@@Grundewalt I use a Seesii 11000mAH spot welder. It will do .15 pure nickel or nickel plated steel straps. Adjustable power and delay time $75

[@Grundewalt]

@@davidbarker3591 thanks a bunch. From Amazon ?

[@Grundewalt]

@@davidbarker3591 thanks, I am in Canada and amazon charges on the canadian site 115 cad, more above the exchange rate ..If I buy from the us, it is even more with the shipping. I look for a system without battery, pluggable, maybe cheaper?

[@divomar7184]

You are a professional 👏 I really love that video

[@MikesInventions]

Why thanks! I really appreciate that.

[@kenedylima2268]

Great video

[@mark9328]

@Mikes Inventions When looking for a spot welder are there any minimum requirements for welding cells. I have plenty of experience soldering, but need to look into a spot welder. Any recommendations for a spot welder? Great video!

[@jacobmartin3389]

thanks for making this

[@SergeyDubinets]

Thanks Mike

[@babyhominid7779]

6:35 the one he covered up looked for a second like one of those "mud flap ladies" on big trucks!

[@antonyguzman8672]

gracias men

[@MikesInventions]

De nada

[@villamef]

Worked! Thank you!

[@juliosalazar6492]

Pero las nuevas celdas samsung que compraste son de las mismas caracteristicas que las originales? Tienen que ser de alta descarga para que no se sobrecalienten

[@marksteele45]

"I hope I don't lose them" "I DID" pops up. That was good! I lose them too. I think they design them that way...

[@MikesInventions]

Right?!

[@PajamaPantsTheater]

Great video! Thank you for the inspiration! I have a small box of old 1.5ah and 3ah batteries that I've been wanting to rebuild but was never really sure how. Question though... I'm looking at the 18650 battery store and see a slew of them. If I purchased, say the Epoch 18650 3000mAh 20A Battery (HJ2), will that make my 1.5ah packs a 3ah pack?? Yes, I realize that they are $10 each, it's more so I understand the different capacities and options...

[@davidbarker3591]

Yes, it would be a 3AH pack

[@richierich4604]

Awesome video nice gadgets