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

[@JohnDoe-pv2iu]

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

[@zenno2010]

Great answer

[@alphanumeric1529]

will adding water to a car battery decrease its ability to charge fully and discharge at the correct voltage and amperage?

[@ericyell898]

agreeded 100 percent john doe i also have seen the samething with what you said.

[@thestonedhedge77]

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 !!!!

[@MrDonnymize]

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.

[@jerryreneau2145]

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.

[@matthewbeaver5026]

Ryobi has a protector in it. You must remove the cover and get to the inner plate that sits below said safety. Just need some security bits and remove the caps on the screws (doing so will void any remaining warranty)

[@justaguy4real]

@@matthewbeaver5026 awesome. Love when someone else throws in useful information. If everyone or more people would share like this, we all would get a lot more accomplished. Good going Matt. And now I [we all] know something new about Ryobi too

[@jordanmassey9440]

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.

[@ineed31jobs]

I had to hammer down a copper wire until it flattens. Then insert into the terminals. Worked like a charm.

[@gbinman]

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.

[@tcatco9356]

@GaryInman Spot on input ma' clever friend. id rather endure head 2 toe brazilian hot wax hair removal vs the fear i have from jus plugging in one household 110v device. I wuz thinkn id add in line fuse 4 ohat + to + 12ga wire. Your 12v inline bulb assy is mo bettr. ! 👊 OP fails 2 addr liklyhood older batt's may take chg, yet only enuff amps that go dead quickly.

[@gbinman]

@@tcatco9356 I have brake lamp with alligator clips on my bench. I use it to quick check UPS batteries mostly, or a load to see how fast they drain.

[@powerwizard8903]

Great video and ballast lamp comment.

[@Alco16-251F]

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

[@siriosstar4789]

For how long ?

[@Alco16-251F]

@@siriosstar4789 I got a good 14 hours so far!

[@daveadams5257]

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

[@jimbetts5164]

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.

[@S.P.B.222]

Sorry for your loss 🙏😢

[@adamcarrillo5099]

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

[@WmTyndale]

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

[@viewthoughmyeyes]

$50 bucks?? you can't post such a low amount of $$ like that and not share where you're buying your batteries!!!??? I even use Ryobi tools mainly because they're cheap to replace and their batteries are $75 a piece on a good day. I do have a couple rigid and Milwaukee those batteries are astronomical 150 plus each

[@baronvonlimbourgh1716]

@@viewthoughmyeyes what? Just get the off brand cheap ones if you need extra. And if the capacity goes down just replace the cells with proper ones from lg or samsung. The cells in there are cheap. A couple bucks a pop only. And the 12v ones only have 3 or 6 cells. And the 18v ones have 4 or 8 18650s in them. These batteries really are overpriced like crazy. And if you have old tools that are still the old nicads, you can upgrade them to lithium as well for cheap. No need for new tools.

[@michaelfranks4289]

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.

[@trafficjon400]

some won't. i done it for years and eventaully they simply give up doing any trick. a few 6-12 v regular battery's. but especially lithium battery's work the best and last by trick charge the longest i've experienced. old lap top batter's work well by trick charge but can be very dangerous. i charged many . best thing is to keep the charging system built on the batery's of 4-6 small round shape. the system possitive and neg- will help prevent any extremely heating or explosion 💥. the right charging current also . even a regular automatic charging system could cause an explosion. i was lucky staying away from it wile charging it out side and in a some what protected area. 2 battery's exploded and 1 flew about 30 feet smoking hot. sounded like an M80 . never again will i trust the automatic charge set . ya i get it wrong on some forgetting charge setting . 🤔😉 lap top battery's do wonders if i do them creativly with skill some times.

[@toddyocom2261]

@@trafficjon400 lol

[@rossinator]

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.

[@thumperman8490]

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.

[@rapidric4445]

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.

[@connecticutaggie]

Sometimes individual battery cells can get reversed. You can't overcome that with two terminal charging. To over come that, charge the battery as best as you can then open it up and measure the voltage across each battery. If any of them are reversed, you need to get that cell to be positive again. Apply a voltage to just that cell in short bursts until it is at least +0.5V then charge the pack as normal and it should be back.

[@jvon3885]

This is why magnetic pulse generation works great. So like quite Bidini motor used as a charger will restore most batteries that are not just trash. I think if we were to charge them every time this way it would add a ton of worth to batteries. Haven't done it but my research shows the possibilities.

[@FourbrrlGrabber]

🤔🤔 did not know that. Any idea as to why ?

[@TheChristonline]

Thanks !

[@trafficjon400]

Thats right . i for got to do that for rembering months to even years its the only practical way.

[@mariateixeira9047]

@@FourbrrlGrabber the batteries haven't been brought back to life, what is actually happening is the BMS has sensed the cell voltage is too low or unbalanced from over discharge. it cut the output of the pack to stop cells being permanently damaged or exploding. pack goes into hibernation. charger is designed to sense this and not charge an over discharged battery as a precaution, when you apply power into the output of a "dead" battery, it bypasses the BMS. "the built in safety system". I have performed this 72 times and only 3 failed. first failure just melted the pack,,,, second failure burned down the shed, not a great deal,, the third failure caused 4.3milion dollars damage to the complex I was living in. if you think these odds are good,,, give it a go,, if you do a lot of them, it will end in sadness eventually unless you have all precautions in place.

[@crispy9175]

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

[@affordableislandlife3125]

It's a begining of a Bromance

[@baronvonlimbourgh1716]

If you keep using the old nicad ones make sure you fully charge and discharge them a couple of times. It will ring back the original capacity and they will work longer.

[@ronharrington8659]

Good video Phil. I realize these hacks don’t work every time. However what do we have to lose? These were going to be thrown out. Everyone we can save, is saving money, and for the tree huggers, the planet. The negatives on replies I see are always going to be there. Like the old saying- “If we served ice cream, someone wouldn’t like vanilla”…

[@jvon3885]

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.

[@trafficjon400]

what are zinc gans? but interesting.my John deer x300 lawn tractor does not seem to give much charge at all so i cleaned the charge relay helped a little . soppose to charge up to 13 volts . i used it a few times to charge battery's and better than store bought charger's. makes sense pulsed magnetic gen- work well.

[@AIRMANBEAR]

where can i get a pulse magnetic generator

[@edrodgers5541]

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 :)

[@dennisp4395]

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.

[@jerrymontalbano3222]

In a similar manner, I have a Snapple 58v battery for my hedge trimmer that is not charging. Can I use the same technique using cables plus-plus and minus to minus to get a significant enough charge to put back in its charger continuing to charge fully? I don't have another 58v battery of its type, but am wondering if I can use one of my DeWalt 20v dc power drill charger wired the same way even though one is a 58v and the other 20v? Perhaps the DeWalt can charge it's 20v up to 20v in the 58v battery?

[@sumthinsbrewin]

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!

[@richardpowell5661]

wire color means shit here, as long as you go to same terminals. he's not wiring a house.

[@aquatiqaquatiq]

@@richardpowell5661 it actually means a lot, especially when someone is trying to explain a procedure like this. If you are going to purplish potentially dangerous activities like this joker. "I do understand that its only for entertainment purposes" ,,, You may as well use correct wire colours to save confusion. People doing silly things like this is differently entertaining . LOL..

[@TomJones-on9rw]

The electrons not know what color the insulation is. I worked at a power company and most of the time there were only two colors, black and silver(bare). Sometimes all 3 or 4 are silver.

[@soonersasquatch5758]

Could i hook up a trickle charger to the battery and charge it that way?

[@franklidgad]

*VERY INFORMATIVE VIDEO!!* I'm going to try this with some older Makita batteries where 2 out of 3 stopped working. At least I still have one working to use to try and charge the other 2. Who thinks Phil sounds exactly like Joe Pesci? (Home Alone) I was waiting for him to start yelling at Kevin. Keep up the great work!!

[@loulasher]

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)

[@IYar56]

They work great till you're on a job with no power or total gross failure. Good to have it all

[@finnmacky7106]

Same. I've been buying all new corded tools and even bought a little dual fuel generator and an inverter for my car so I can run them any time

[@rodneylayne1]

@@IYar56! ⁷

[@supertrooper7403]

Yep, you can always tell an accent from Alabama.

[@WmTyndale]

Ees a New Yorkr or from New Joyzee. No?

[@waynewigger9904]

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

[@TheChristonline]

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

[@spencerboaz2385]

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 .

[@danstein8305]

I learned a long time ago that dewalt tools and battery packs are definitely NOT CONTRACTOR TOUGH as they used to advertise! I switched to Ridgid and Milwaukee and love both of them! NO MORE YELLOW FOR ME!!!dewalt is CRAP!!

[@369ThegoosedrankwineThemonkey]

Do you have the red wire on the negative side ?

[@KOrnhOliO1]

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. 😎🤘

[@telemark22]

You nailed it. Also, you can accomplish the same thing many times by putting the non-charging battery back on the charger over and over. It takes a little charge each time until the charger finally recognizes and charges it.

[@petestreet7535]

I was wondering the same thing.

[@matthewbeaver5026]

It depends if it's just so low the charger doesn't recognize it. You may save it. If it has a dead cell. I may charge this time but will return to this none usable state when drained.

[@magnum164]

One thing I missed that you may have covered but I didn't hear it. The batt used to restore the dead batt "must" be of a higher amperage or or equal amperage to balance charge, not just voltage. For instance I have two Kobalt batteries 40V, one is 5amps and is dead, the good one is only 2amps. It will not equalize the batteries, its amperage is just too low.

[@scottyhester1]

Could you revive a 12v with a 20v or would the voltage be too much?

[@wam7484]

Totally wrong information. Batteries are rated for voltage and capacity (amp-hours). Capacity has to do with how long it will last, not with how many amps it puts out. No problem paralleling two batteries of different capacity. But voltage ratings must match.

[@magnum164]

​@@wam7484 Battery Capacity Definition Battery Capacity is defined as the product of the electric current flowing in or out of the battery in amperes and the time duration expressed in hours. Correct, place a screwdriver over a batt and it will deliver ALL of its capacity in AMPS in a few milliseconds. Put a resistor inline and you can control the the time and AMPS pulled from the batt during discharge. Basic battery chemistry for over 50 years I have been working with them. The problem with your theory is batt with the same voltage and different capacity will discharge at different voltage:capacity levels. Batteries are often given a suggested discharge and charge rating of the "safe" rates they can be charged at.

[@magnum164]

@@scottyhester1 Sorry did not see this till now, but yes you can. Car batteries need about 14-16 volts to charge, my lawnmower does about 15 volts. Not recommended as the 20V can probably deliver more amps than your 12V can be charged with, most 20V (I have used a 19V laptop charger) chargers can deliver 2.5 to 3 amps. But taking lithium batt you need to check the BMS system to what it can accept. I have a 9V lithium battery and it is charged with only 5V. The reason why it can do that is the BMS splits the voltage into the appropriate voltage for each cell, which is probably 3.2v. Instead of balancing them all at once, it appears to balance them one by one, and I can hookup about 4 to a single 5v USB port, or fast charging port with 2.5 amps output.

[@tinathrower7266]

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.

[@gungagalunga7761]

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

[@truethought369]

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

[@elgato1013]

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!!

[@peterdickinson8939]

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.

[@aeromech8563]

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.

[@davo8802]

This guy must not be doing KZbin anymore. Been over a year since last video

[@djprojugs6606]

I'm just replying cuz I'm also named phil lol

[@erictownsend8711]

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

[@AR-ds7kc]

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

[@stevedoughty8753]

Try hooking the hot wire then the ground. This should stop the sparks.

[@stevedoughty8753]

Hi

[@scogin2670]

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.

[@defaultHandle1110]

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.

[@walkabout5]

What sort of battery did you jump it with? I have the same problem with my kobalt 80v

[@mokopotaka-xi3jt]

Does the voltage need to be the same on both batteries? I have an 82v B&S battery as well

[@frankstanton4712]

Hello Phil very good video, I have a query, is it possible to charge a 12 v flat battery from an 18 v system?

[@mikefader1988]

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

[@jimstoyles7617]

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

[@armandorodriguez6447]

The best recharge video out there,thanks

[@smark1180]

Didn't work on two new B&S 82V batteries that were not used for almost a year.

[@wnight55]

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.

[@ejicon3099]

Great video. Fast, clean and easy. I have a Festool battery that refuses to charge. The contacts on the battery are flat unlike other power-tool batteries. What do you suggest would be the best connector for me to jump start it? Male/Female spade connectors won't hold in place. Any help would be appreciated. The battery is a Festool 18V 5,2 Ah Li-Ion Airstream.

[@ejicon3099]

@Christopher Webb Appreciate it. I did just that except I have two Festool batteries so I ended up using alligator clips on both side. Worked like a beaut. My battery has been jump started and everything is working again. Save so much time and money. Yah!

[@FirstLast-sw6ts]

Great video! FYI, make sure there isn’t any voltage over terminals before checking ohms. The meter can be damaged

[@sparlokjahdropper6049]

@Jesus has given you all. Repent or die. "For my subjects shall announce my return wherever fine tool tips be shared...so sayeth Lord Voldemort." Prisoner of Azkaban 11:4 JKRV

[@bobwright992]

MOST HAVE A FUSE

[@Dinco422]

I have done that xD.... rip my multimeter.

[@toddrunyan7348]

​@@Dinco422 most good quality multi meters have fuses inside to protect them from frying. My Fluke meter does as I forget to switch my settings and had to open it up and replace both in mine.

[@jimprior5700]

I was surprised at the "continuity check too"

[@soekawas]

Awesome. Going to try this. Thank you.

[@brianrussell4717]

If you have batteries that are lithium (at this point everything is now), do not let them fully die and do not let them sit on the charger longer than needed. This includes your phones. Soon as any green light appears saying your battery is charged, take it off and use that battery until it is close to dead before recharging it. This makes your batteries lifetime last far longer.

[@baronvonlimbourgh1716]

Lithium cells actually live longer if you do not fully charge and discharge them. They hate full cycles, use it from 85% to 25% and then charge back to 85% etc. Will make them last a lot longer. And if it sits full on the charger for a couple of days it should be fine, the charger k ows it is full and will not charge it further. And a lithium batrery should not auto discharge over a week or so, so it will just sit there full. Your phone is a problem if the phone does not use power from the cord directly and will always run from battery. Then it will discharge when it is full and the charger will recharge it every time a couple of percent has been used. That is bad. If it just runs of the charger and the battery simply remains full and is not used until the cable is disconnected then it doesn't matter. The batrery is not cycling in that case. The nicad batteries that where used before lithium cells are the ones that need full charge and discharge cycles because they have that memmory effect. Charging before they are empty will make them hold less charge. Multiple full cycles will bring back the capacity. Just charge them fully, then discharge fully in one go, then fully charge and again continueisly discharge. Do that a couple of times and they should be good to go again. These are the older power tools like the dewalt ones in this video. They where horrible for this but can therefor also often be brought back. Lithiums usually need a cell replaced to bring them back properly.

[@poolhall9632]

I used a yellow Dewalt xps battery to charge my dead car battery enough to start the car. Used some drill bits to extend the points and jumper cables to connect.

[@kennethsonier1766]

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 👍☮️

[@DanielFinney-w3n]

Instead of plugging into another battery, can I plug into the outlet?

[@frankstanton4712]

Can I use a higher donar voltage (14 v, 20 v or similar) to jump a lower 12 v battery?

[@DJ63phx]

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

[@captaintimbailes7971]

What's the run time test look like after these dead batteries take a full charge? I'd like to hear that if you don't mind.

[@garymazur2217]

Anywhere from 20 maybe 30 doubtful. New this 15 years ago using old 12 volt car battery never worked right

[@jerichojoe307]

@@garymazur2217 🤷‍♂️🤷‍♂️🤷‍♂️ don't know what to tell you. Maybe there were other problems inside your battery. Just did this two years ago to my old car battery because it was too dead for my smart charger / maintainer work on it. Just had to check my water levels and make sure that there wasn't a short. Give it a jolt from my jump pack and let it equalizes, then popping on the smart charger charged it up the full and it has been absolutely fine and puts out its full rated amperage. I had initially bought a new battery but after Reviving the old one; and letting it sit for a couple of months to see if it would hold charge; I put it back in the car. It's been running absolutely fine at full amperage without going dead ever since. Now I have a brand new battery sitting in my closet for if it ever does go bad. Sometimes things just sit too long and need a jolt🤷‍♂️🤷‍♂️

[@MultiCrazyCar]

@@jerichojoe307 Sell the new one while it has a chance as you will sulfate/ruin your neglected new battery unless you provide a maintenance charge every 3 months.

[@catstevens5890]

If you’d looked carefully he did connect positive first, Just used a green cable.

[@mstanton1ful]

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

[@coloradomountainman8659]

Got me a box of 12 or 15 dead Dewalt 18v batteries that I hadn't gotten around to tossing. Guess I can restore them and keep the old Dewalt drills and saws working. Will try it on a couple old 7.2 and 9.6 Makita batteries that I still have that are dead as hell and haven't been used in probably 20 years or better. Thanks for the info.

[@watchdogu.s.a.8973]

It will work only if the batteries were still "good" batteries when you stopped using them. If they were already worn out to the point that a full charge didn't last very long when using then the ONLY fix is new batteries. Sure, you can charge them enough using this technique that the charger will then recognize them but it won't them last any longer than would before.

[@jakesmith5739]

How can you identify the positive/negative terminals on the 18V DeWalt give they are unmarked?

[@tyrzxv]

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.

[@wetwriterrr]

Thank you for you added details. Ill hunt down that RC Hobby charger.

[@tyrzxv]

@@wetwriterrr I should add, that it doesn't have to be a hobby charger, there are lots of different chargers or power supplies that will let you do this. But the hobby chargers for Lipo batteries are probably your easier to find and cheaper options, since RC Hobbyists like to charge their lipo and lithium batteries using custom settings, but usually have default safe charging settings. Most tool batteries are just a number of 18650 lithium batteries put into a plastic case.

[@Semper_Fish]

You must be the new know it all.

[@JamesSmith-jq2jc]

I found a 14 volt drill and small circular saw in the trash. I took the batteries out of the battery pack and soldered a 20 ft. length of lamp electric cord to the connector inside battery pack, drilled a hole for cord to go through, assembled it together, then put clips on the other end. I can use it off my car battery. It comes in handy at times. I can switch easily from drill to saw.

[@joshking963]

12v to 18v cordless batteries and other types of baterries can be fixed with a 12v car battery charger much easier and safer because a decent charger "should" have a voltage and amperage selector, a built in voltage gauge ((so you don't blow up two batteries using just wires!)), and of course the most important thing about using a battery charger you turn it on after its hooked up ((reduces the risk of being shocked/blowing up batteries!)). other than being unsafe for amatuers to do, this is cheap way to fix any uncharging battery, just not safe.

[@tuffy16]

On my 20v Dewalt I'm using a small trickle charger the pos and beg connected and I get a no connectivity light other slots charge and happy (cant find my ohms metre) good and dead batteries test like that and both won't charge on power station, good battery still powers my cordless grinder. I think both got wet in the rain tho..any ideas ? Thanks good vid!

[@leftylou6070]

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!

[@Dansk55]

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

[@Recipro1]

GOOD clear video and nice vocabulary. THX

[@flipmode00]

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:" 😂🤣😂🤣

[@PIANOSTYLE100]

I have a some batteries to troubleshoot. I used to troubleshoot Tvs and various electronics. My batteries have been a bit of a mystery. I got rid of scopes etc Where do you get schematics? I have a woodworking hobby and would like to get my drills etc. fixed. Thanks in advance.

[@j3ffn4v4rr0]

Instead of another good battery, can I use an 18V DC adapter?

[@brucemarmy8500]

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?

[@fernandosanchez-qx3ys]

hello there buudy i have ? do you have to jump them again after you drain the batteries. have many times did you recharge them with out having to jump them again...

[@musoseven8218]

Hi, That's really good to know, I've several the same. Were the DeWalt batteries NiCd's🤔🤔 Also the booster battery, what type was that please 🤔 Many thanks in advance 🤞✌️😊👍💜

[@mysterythecat971]

boosting cells... but what is the recovered amp hour ratings? Did you get back the full voltage and amp hours, or some lower values due to damaged cells. yout not saving money if the pack dont last.

[@thethoughtmaster]

You can only revive it if the battery was not charged for a long time. If the battery is blocked with dendrites it will either not charge or short circuit and might cause a fire. All batteries start when built having no electric in them, it must be possible to force them to hold electrons, it takes longer the first time.

[@kwacz]

The charger just wants to see a minimum voltage. Connecting it like this sends a large charging current into the dead battery. You should only connect it for about 5 seconds then try to charge it immediately. If that wont work try 10 seconds. If that dont work let it rest because it could be heating up. Then try again. Do not leave connected too long. Monitor temp. When it does finally start charging make sure that the temperature of the battery is not too high. I like to let it charge for 5 minutes in the charger after i boost it. Then take it out and let it rest for 10 minutes to cool because they can heat up internally. Then put it back in the charger and let it fully charge.

[@tyrzxv]

I would add, that each time you do this "shock" charge, you are lowering slightly the life of BOTH battery packs... You are definitely exceeding their current limits and basically overloading the battery chemistry abilities of both packs... there is a reason the chargers don't charge the batteries in 1 to 5 minutes. Also, usually each cell in the battery packs have an internal fuse. You can possibly "pop" this fuse by doing this battery-to-battery connection and if you do, you have permanently disabled that battery pack...these aren't fuses that can be replaced.

[@s_p7231]

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.

[@bjjthaiboxing]

Hey bud, if the red wire is supposed to be positive... You got it backwards? The Milwaukee battery is marked for you to see? Just to be clear, I'm not talking about DeWalt battery.

[@roadshowautosports]

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!

[@lawrenceakins6045]

If u

[@frycorona]

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.

[@apfelsnutz]

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

[@041375lalo]

Dude I don't know if you noticed but the plastic on the Milwaukee batteries has depositive and the negative engraved on you don't have to do all this tasting each one by one of the slots

[@djprojugs6606]

I'll give him the benefit of the doubt and just assume he was simply trying to show what you would do just in case those markings are not there on other batteries lol

[@anonimoporsiempre6033]

@@djprojugs6606 You got that right Not every body is Smart like you 👍🏼

[@sweetguy3219]

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

[@shaunbruns4153]

Milwaukee has a five year warranty. I usually just them back and you can go on their website and print out the form so you don't have to pay shipping. They been great with replacing broken tools and batteries.

[@Jameeel1122]

Would a Milwaukee 18V battery fix Victa 82v and AEG 58V batteries as well? Or do we have to use the same voltage on dead batteries?

[@davidmilligan4925]

Can you charge a battery using jumper wires connected to a different brand charger

[@dr.george459]

Could you use a 12V car battery charger to charger the spent battery?

[@jamesstiltner8885]

Could you trickle charge the DeWalt with a cell phone battery chager

[@Vincent0Vangogh]

Thanks

[@douglasnewman4163]

A really great video instruction! Thanks for this!

[@tnasituning8173]

Nice 👍🏽... The m12 Milwaukee batteries seem to be an issue. none with the M18... would like to see where to place wires on the M12s

[@bryancausey1122]

good

[@bobkoskovics2530]

When you plug the battery in the charger if the battery is weak and does not show enough voltage to energize the charger add voltage to the battery to bring it up higher in voltage and plug it in works every time new style chargers don’t see voltage will not make voltage

[@juddrobinson6762]

Looks good! Did the batterys last as long as they should after you charged? I have old batteries i charge, in the drill, you get maybe 15 minutesi

[@8bitsamurai6]

Well cells wear down over time aswell from use and age depending on how you charges it and usage.

[@Nerino666]

@@8bitsamurai6 just make sure to charge them to 95% when they're on25/30%...., certainly newer type of accu's> makes them last almos double than topping off 100% and letting down to 3%...., not good for most of battery packs, made out off 18650 cells...

[@cheeseburgerexpress8624]

They don't last as long and don't put out as much power either but as a quick fix to do small jobs it suffices!

[@danstein8305]

How bout wearing safety goggles to protect your eyes while making the battry connections?

[@billknight7442]

@@danstein8305 no eye protection is needed

[@The1313jeff]

Can you use a battery charger ? a low voltage like the type you leave your car plugged into in the winter ?

[@bbbnz50]

I thought when you jump start them It was only for a few seconds ,, Can it hurt if you leave them on longer, so what is the longest you can leave the jump starting for thanx ?

[@markpyser1631]

Hey Phil - Great tips - I know this... Connect your positive terminals first then negative.

[@fcres5845]

Wats the difference with plugging the dead dewalt battery to an AC charger?

[@stephenbrooklyn7945]

@@fcres5845 he is getting a little power in so the charger recognises it its completely flat charger dont see it in simple terms

[@williamzander4732]

No what’s the problem is the battery has to have some voltage for the charger to kick in and you can build a plug or adapter that fits you drill or battery then slow charge off a charger till the battery show voltage but new charger won’t charge without voltage you have to have a older charger that’s trickles like JC Whitney had years ago .

[@kennethhuete6724]

Please forgive my ignorance. Do i need o buy a Milwaukee battery to perform this repair?

[@richardbarkley9909]

I recently bought a Craftsman 19.2 volt 1/2" drive inpact used. 2 batteries included. They seem to take a charge but won't even break 1 lug nut loose. Is there any way to fix these?