CORDLESS POWER TOOL BATTERY HACK! HOW TO FIX THE DEAD ONES! STOP WASTING YOUR MONEY! TIPS AND TRICKS 

First, I would like to say that I think that you are doing a good job of helping people learn to understand the batteries and charging systems. I want people to know that @3.54 the 20 volt reading that you got is Not the voltage of the battery that you are trying to fix. With the jumpers still attached, you are reading the voltage of both batteries wired in parallel. People who aren't really familiar with electricity can get confused by this and think that they are checking the voltage of the battery they're trying to fix. When repairing old battery packs, most of the time you are going to have to open the case and check voltage on the individual cells. One (or more) cells has usually given up and has to be replaced. (Quick FYI, If folks won't run the battery pack completely dead and will return the discharged battery to the charger when swapped, Your batteries will last many more times.) When you do this and replace a bad cell or two, you need to have another power tool battery to cannibalize for 18650s. The 18650s from laptops and modems won't work for replacements. The cells are not strong enough for heavy discharge like a tool battery. Remember a few years ago all the 'hover-boards' that were catching on fire? The problem with those was, the 18650s that had been installed in China were 'laptop' type 18650s and couldn't handle the heavy/rapid discharge cycle from the hover-board. They needed to be built with the high rating 'Tool' batteries but weren't (for whatever reason), and this caused them to catch on fire. I work on all kinds of batteries and most of the batteries being replaced as dead have had one of three issues. (1) The pack was ran completely dead and then not recharged right away, (2) The battery pack was left in the back of a truck and got rain water in it. And (3) For golf-cart and automotive batteries, the water level wasn't checked and maintained... Nice Video! Ya'll Take Care and be safe, John

My Guy !! I ALMOST just bought 2 new Batteries. @90$ each. IT WOULD of been A Waste Of Money!!! I Can't Believe they don't tell you about this. Or sell something SAFER for those NOT Skilled Enough or Afraid to Do This... It WORKED. THANK YOU !!!!

Phil AND all the smart people commenting and sharing your knowledge , I thank you !!!

Did it with my Dewald 18V XRP, runs like a champ again! Thanks for teaching this hack!

phil thank you very informative got gifted approx from an retired fried of mine battery tools dewalt, hitichi, makita, bosch. all battery powered all had two batteries each except makita that had three not been used for 8 years plus watch your video even though i never had the testing equipment but tried it as i had nothing to loose all tools are functioning thx

Thanks for posting this. I was just able to resuscitate a 12v milwaukee battery that wouldn't charge. Didn't have any alligator clips lying around so I had to carefully use uncoiled paper clips as cables. After 20 minutes it's as good as new! Saved a few bucks and just as good, didn't have to create any unnecessary waste.

I have this a try with a dead 20v Black and Decker battery. 30 seconds hooked up to another 20v battery and it charged nicely. Thanks for the tip.

Awesome Hack Phil. Love the input and advice. Stay safe!

Thank you so much for putting this video together I ended up jumping a Black & Decker 18 V that was not showing any type of charge with a 12 V Black & Decker I had and because the prongs were the same it was an easy set up that only took two minutes. I then put it on a charger and the charger read it at that point. Saved me at least $30!!

Awesome. Going to try this. Thank you.

This is the best battery rejuvenation video that I have seen, if it works for me. None of the other ones have ever worked for my old ryobi batteries.

As these things go I just dropped off 3 batteries at the recycling center this afternoon all dewalt batteries, 2 xrp's the other a nano like the ones in this video. as it turns out I didn't have a nano charger and this battery was beat so no big loss. The Xrp's are ok for what they are , but have upgraded to the 20v lithium ion impact driver and drills. I'm going to try this on some older porter cable and a makita 9.6 which is at least 20 - 25 years old. thanks for the video well done. Wish I came across it 48 hours ago.

From one know it all Phil to another great channel just found you and Subscribed! I have done this a few times over the years and it works a treat.

A really great video instruction! Thanks for this!

Very cool 👍 I've got a DeWalt that's been sitting for 5 years with dead batteries, I'm going out to the barn right now and hooking it up to a Ryobi that I have that is perfectly fine, wish me luck 👍☮️

As a matter of safety it's a good idea to also check 5he cells. They may be corroded if they've sat for long periods. Like alkaline batts in things like flashlights. Also better to do this in a large well ventilated area just in case. Meantime Phil , thanks for the informative money saving tips sales staff would never tell us. That is, if they even know.

I had a couple of batteries that hadn’t been used for a year as they wouldn’t charge. Tried this and they work a treat.

I have saved a few batteries like this. Saved a Dewalt flex Volt a 100.00 dollar value. Good advice. 👌

Thanks for that, this is exactly what we all need to know. there is too much waste due to Commercial practises.

I buy "bad millwakee" batteries on a regular bases for my tools and 80 % I've brought back to life using this technique. There is a percentage that have actully failed and can't be brought back so easily but the ones that do last me years after I do this. Most importantly anyone doing this needs to take the time to learn how to use a dmm and understand at least the basics of volts amps watts and the danger. The danger comes from a lack of basic knowledge so it can be a great technique but it's a must you take the time to understand what your doing and how to properly do it and always take necessary safety measures prior to beginning because crazy things still happen to the most experienced people these people are still around doing it to this day only because they took the safety seriously before beginning each project. Good luck and enjoy saving big money I've saved literally thousands.

Awesome, i’ve been holding on to 3 dead ones, including a 250.00 M-18 12.0. Thanks!

Excellent video.... I learned something ! THANK YOU !

Phil. Don't take this the wrong way... but i love you. THANK YOU for this video. I can't afford new batteries and this fixed the ones I already have. You're a Saint

Great video with great tips. Thanks for sharing with us.

There is something to be said for mains driven tools ...my original Bosch drill , about 38 years old is still 100% functional and with its original brushes..works a treat complete with chuck key.

Mr. Know It All, I Do like the way you check and double check your readings, and tester. 1 wrong move it's over. This was a great tutorial on rejuvinating a dead battery that wont charge. I build 48volt 16ah bike batteries, and I picked up good info.

Excellent. Thank you.

OK, this is cool. I'm definitely going to try this.

Great tip!! Thanks Randy

GOOD clear video and nice vocabulary. THX

I appreciate this, I left one of my RYOBI 18V lithium batteries out in the rain and it rendered it dead and defective I'm going to try this and see if I can't give it a fibbulator shock with another good and stronger RYOBI 18V lithium. I honestly can't thank you enough for the info.

The Best! These batteries are now around $50 each and even more. For casual use the rehabilitation saves a great deal of money.

Thanks Bud! I have the same batteries you do so I shouldn't have any problem. The Milwaukee batteries have been sitting in my tool box for at least 15 years now without being charged and when I push the battery check light it gives me three bars. I also have two dead XRPs 18 vdc. This will give me something to fart around with. Thanks!

Is it me or does this Dude sound Like Joe Pesci, lol Man what an excellent Video. I dont even what to know how you figured it all out, all I know that when I purchased my first set of Milwaukee tools, all came with a battery or even a couple of batteries.. I really like Milwaukee over other brands therefore all my tools are milwaukee and if your like me, I like to keep my batteries charged and installed in each tool. I think switching out batteries is a waste of time and I like to get the jobs done rapidly. Here is why I appreciate you and thank you kindly for taking the time to record and placing this great money savings idea. I moved to Michigan from California 6 years ago and did a few adjustments to the new property upon arrival however due to bad weather conditions I had to put everything away 8n the uninsulated garage after 3 weeks of being here in Michigan. Well a few months after almost being burried in snow, I was once again going to continue with a few small projects and I love using my tools for everything...well almost everything. Now get this, while attempting to re-charge severall batteries.....You guessed it... Failed. I thought perhaps the electric panel was not producing correct voltage. So To Make A Short Story Long! I ran to look for a Home Depot and the area where I Reside only have a Humongous Giant Store 3 times bigger than any Home Depot ive visited. well my like sucked cuz they do not supply Milwaukee tools therefore I googled the closest Depot only to be 2hrs away. With only 2 good batteries wirking, I took off to buy a few new batteries so I thought... when I walked up to the shelf OMG... MY JAW dropped to beyond the floor n then some. Jesus Christ My wallet cried and jumped out of my pocket all the way to my truck parked outside. Wow $ 99.00 was the least expensive, the one i wanted which holds charge a little more only came in a 2pk @ $269.99... really? have prices really gone up that much?... so I did the math and ordered at Home Depot Online for an entire new set with 2 chargers bunch batteries n new impacts, repsaw, woodsaw, metal saw, Vacuum etc. 4 days later ups dropped a huge box in front if my door. I was hapoy to have a new set if tools but for some reason, my old tools felt like a tool should feel like in my hand, unlike the new ones felt flimsy. My Old tooks seem to have been made better idk. with all that being said, I saved all the dead batteries hoping that one day I would find a solution and today I came across your Tutorial while looking for a way to adjust my new thermostat. thank you for saving us money n making me smarter. Moving Forward Adam Carrillo

It worked !!! Thanks you saved me 100$

I just followed your example and used an 18 vdc battery to charge a 9.6 vdc SKIL cordless drill battery. The battery had not been used for about two years and showed not charge with my volt ohm meter. I touched the contacts for about 5 seconds, observed a spark and then check to see if the dead battery had a charge. My meter read 8+ volts after the brief contact! Then, I attached the charger which remained green (only one led on this charger). When I tried the charger before the procedure, the led light went out (but came back on when I detached the charger). Thank you for your How-to program :)

Thanks for the tips!!👍👏😎🇺🇸

I work in this industry and this does work. The reason the chargers don't charge a "dead" battery is because its a safety issue, you don't want to charge a dead short, so most of the time you only need to "boost" the charge so the charger senses the battery, most of the time a few seconds is good enough. DO NOT leave a battery "boosting" for and extended time it may end up catching fire, especially lithium batteries can go into a "runaway" state and catch fire. Another tip that does work is put a old battery that seems "weak" in a freezer for a day and then charge.

Batterys are more expensive then the tools some times but I think this will help you and im sure it's going to help me thank you

Absolutely impressive. The little things you do to make life easier in the long run!

VERY, VERY helpfull. will try with a few batteries that i had planed to replace, Thanks very much for sharing.

Great stuff mate top tips 👍

Thank you!!!! It worked 😊

Good stuff thanks for sharing this video Phil.

Great vid, Phil. ty

I recently decided to go back to plug-in power tools because of this problem, and the problem of discontinued equipment. Also, Phil has the best accent ever (I have a very pronounced accent myself)

I know that pulsed magnetic generators work well with batteries. I've researched quite a bit and I'm working on my own version. I will charge every battery this way once it's done. I also build my batteries out of zinc gans. I hope to introduce my rechargeable home power system in a year.

I've used an old computer PSU with a DC-DC step up boost converter to charge up practically dead batteries back to life. Brought back to life a 12v AGM battery that I forgot to remove the OBD connector that drained the bat to 5v. The regular charger couldn't do it but the 1200w dc-dc step up converter hooked to my old dell power supply did the job perfectly. Only cost me $20

You are the man! Thank you.

What this shows is it taking a charge after hooking it up to the other charged battery. What it doesn't show us how long of use, of the power tool, he got from each of these charges. That's typically the issue here. It charges, sure, but the charge you get doesn't give you much time of actual use with the tool. Yes, that can vary, but a lot of time these batteries give you very little actual use of your tool. Great to try... Some will give long charges and some won't. 😎🤘

when connecting batteries with such a high differential voltages (nano 1v - Milwaukee 18v), I would add a 12v lamp (brake lamp) in the circuit. at first the lamp will glow but will dim as the low battery charges. No high current arcing or risk of damage and the brightness will indicate progress.

Nice job.....learned alot😊

Thanks Phil. I have a small collection of dead Milwaukee 18V batteries. This will be an excellent help

it is working! thank you!

Thanks for the info! I’ll give it a try! Cheers from the Bulldog 🍻

You just saved me some money have some batteries that are doing the same, have Lowe's and home depot power tools

Years ago, YT mechanics were considered a joke. I never felt that way and have learned so much from YT I cannot even quantify it.

Saved all my Milwaukee batteries doing this good looking out buddy almost bought new batteries

Works good, just revived two old dewalt batteries that were dead

Thanks, Phil! Awesome video! Did you ever make a video about the shorted battery repair? I’d love to see that one! Appreciate you helping us all!

Aye thats one of the best videos I seen in Months 👍

Thanks dude you're really cool we'll be watching and learning and not buying batteries LOL

This works but very rare they hold up for long I've done load's

Or you could just buy Ridged tools with lifetime battery warranty . I'm still using the same drill I bought 17 years ago on it's sixth set of batteries . Far better than any Dewalt I ever owned . Great video on saving old batteries . No I don't have any connection to Ridged but it's the only battery powered tool I buy now .

Fantastic. Ty

great video, good tip! thank you.

Fantastic and it worked

You are awesome!! You got yourself a new subscriber 😁

I had seen this kind of hack on a video some time ago. Your video actually taught me something! Now I will be able to save dead batteries too. Excellent, brother, excellent. Happy to sub. You from Bklyn?

Cool! You’ve just earned a new subscriber!

Thank you, I will try it

Wow fantastic video bud. Cheers. Got a few batteries that won’t charge. And yep I’m gonna be doing this 👍👍👍 Thanks for sharing this 🤩🤩🥇🥇👍👍

This is good to know. It is better to let some things remain unknown.

Brilliant

I've used the same principal using a good DeWalt to revive a bad DeWalt. You really only need to connect for a max of ten seconds in my experience. For the sake of novices, please make sure to use the correct wire color code. I noticed that you had the red wire going into the negative terminal on the Milwaukee battery. Keep up the good work!

Liked and subscribed! Thank you. A bunch of M18 that I thought was dead.

I've watched several of these battery repair videos, and I've seen several times the guy says well it's dead no fixing this one, but he never opens the thing. If you can't get it to charge, and it's showing Zero volts, take the 4 screws out and look inside. There's a fuse inside. Or more like a jumper. It doesn't look like a fuse, but it can melt or even just wiggle loose. If you can tell it's tripped... Melted. You can replace it or... (I'm only telling you what I'VE done several times, I'm NOT saying it's a great idea) I've soldered a thin piece of wire across it (Thin enough, so it will melt if it overloads). You're not on the batteries, so you shouldn't have to worry about puncturing one of them. Or you could splice a real fuse in there. I've fixed more like that than I have by jumping them.

Great information

Brilliant 👏

Awesome thanks

You got me at "what would be more nice if you hit that like button, because I know you're liking what you see so far plus I'm saving you money:" 😂🤣😂🤣

It works. Was about to buy new battery then saw this video. works on my fatmax. connected 2 leads, pos. neg. great thanks for the video.

Interesting video nice work.

Amazing.

So cool. Thanks 😉

Phyi, I am impressed.

I have several Ryobi batteries that are dead and they're lithium I'm gonna try that tomorrow see if I can jump start them. Thank you for the information

great job

That was awesome good tips thanks man😅

This is nice to know !

loved it ,great vid

Awesome...

Maybe you can mark the batteries so we know that it is the same battery. I know that it was but some people would not believe it! Thanks for your cooperation and understand. Good job

For some reason, the intro made me LOL! 😆

Connecting a battery to battery can be very dangerous though... you can burn the wires, or you could cause a thermal run-away and cause the lithium to burst into flames, which you can't put out... you just have to wait for it to stop burning. If the cells are old/damaged, it's possible it might only take seconds for this to happen. Normally the cells in the packs have their own fuses and you'll blow those fuses and permanently disable your batteries forever. (It's not a fuse you can replace). So you do run the risk of killing both batteries, especially if they aren't using high quality cells. (Although Dewalt and Milwaukee use very high quality cells in their packs) These chargers are only looking for a minimum voltage... they aren't really smart chargers. The best way to fix these below voltage battery packs would be to use a hobby charger (RC Hobby) where you can set the voltage and current (amps) to very low trickle like 1/4 an amp. Doing the quick shock charge thing is actually doing harm to the chemistry in BOTH battery packs, because you are exceeding their rated current limits... a short wire does not have much resistance, so basically your overloading the capacity of the battery chemistry.

You are my figgin' hero, dude........my friggin' hero! Liked & subbed ! Peace

Very cool!

At one time I knew electronics.. I inherited a bunch of batteries etc with a bunch of broke drills etc. Plan to watch this shortly. Also most of them have broke parts.

This worked with garden tools batteries too. 82v Kobalt (Briggs and Stratton also work) 5 mins of battery mouth to mouth and it came back after months of being dead and not detected/ error on charger.

May Want to add some series resistance to limit max current. Initially the battery to be charged will have very low voltage. High currents generate large amounts of heat.