Kinda like when your new fangled automotive battery charger says “sorry but this battery is dead and I will not be part of any further efforts.” But the crusty old analog charger from the 70’s say “hold my solo cup”.
That's why I keep my analog charger from the age of the dinosaurs. When my battery was completely dead (from leaving the dome light on all night), the breaker popped a couple of times and then it charged the battery and I'm still using that battery years later.
People have been doing this for a long time for lithium batteries with BMS boards in them. The reason this works is because there is a set low voltage cut-off on the board. Usally 3.2v per cell. If the voltage drops below that set voltage (from sitting a long time, or a bad cell) it will not take a charge because the BMS isn't going to allow it. So by using another battery you can raise the cell voltage up pass 3.2v (each cell) and then the BMS allows the charger to charge the battery.
I believe part of it also is that all the name brand lithium batteries have to have a “handshake” with the charger and the low voltage doesn’t let the battery tell the charger it’s still good.
We have lifepo4 batteries on our boat and returned to the boat after a month and found them "dead" (forget what incredibly stupid thing we did to cause this). Anyhoo... The charger (when we turned on the shore power) would not charge them. The engine's alternator, however, didn't care how dead they were. We ran the engine for 5 minutes or so and it gave them enough juice to allow the charger to finish the job. Thereafter, they were fine charging off shore power.
Whaaaaat! I had a 12ah Miwakiah batray that arrived doa. Unfortunately I opened it a month or two after arrival and lost the receipt. I held on to it because I did not know how to dispose of it. I have stared at that batray with the evil eye for over a year. Now, with your video, it is alive!
This won't fix every battery but if conditions are favorable, there's a solid chance for it to work. The issue being fixed by jump starting like this is the overall batt pack having too low a voltage for the charger to recognize it as 'safe to charge'. So you're just giving it a little boost to increase the voltage for the charger to say, 'yeah, it's safe'. This won't work if there's a cell in the pack that has or is failing altogether. That's the stage where you'll need to take the pack apart, find the bad cell, and replace it w/an identical replacement if you can. Lots of vids showing that process.
@@marsbase3729 Yeah I was wondering that as well lol. I'm sure there would be a way to strip some 4mm bullet wires on the charging end and hook it up. Plus you could put it on a really low amp charge to charge it really slow to help the chances to restore the bad/low cells.
I do not understand what you mean. A surge protected power strip is alternating current and 120 v. A battery pack is 3.7 to 40v DC. Special wires would be needed and the protection circuit principle is not followed
@dennisgarber you plug the dead battery on the charger - plug the charger into a surge protector with a on off switch. Turn on wait a second turn off - keep repeating for a minute
Totally works..manually forces juice into a completely dead battery, which needs a tiny bit of reserve to communicate with the charger. This can also be done with a couple of leads and a portable battery charger. Did it to save a Flex battery last year.
Not going to lie, I haven't watched your vids in awhile and was even unsubscribed. This one happened to pop up and I had a milwaukee battery that was dead and I was needing to try and warranty. Just tried this and it is now on the charger coming back to life. Subscription earned.
Nearly everyone already knew this but its great to see how excited someone gets, like this guy, when its discovered. This trick has been popular for the last decade or more with lithium battery jumpers that wont charge once they go below a certain voltage. Just jumping them with another battery usually brings them right back.
My brother I thought you knew that trick or I would’ve told you. I’ve used small pieces of wire too. This has saved my bacon a time or two!! Great vidja as always!!
the "dead" battery has a very low charge, the charger requires a minimum charge in a battery in ir order to "see" it.. jumping it with the good battery brings it up to that minimum .. I successfully revived an old ryobi nicad using a 13 volt dc power supply
I have fixed a couple of Ryobi batteries in a different manner. I took them apart and found the low cell using a dvm and brought it up to the correct voltage using a variable bench dc power supply with current limit. They have worked for years after this fix. One I couldn't fix because the battery had a negative voltage on one cell. I to fix that I would have had to purchase or manufacture a cheap spot welder for nickel strips so I can replace the defective cell. At that point I gave up because it was only 1 battery.
I've been doing this for years. Back then, a friend showed me how to jump-start a dead 0% battery. It was a dumbfounded moment, like how we know how to jump-start a car but never thought about other batteries.
I have been using this technique for a good while. Certain conditions are required though. Worked on my Dewalts. Not Metabo at all. Ryobi hit or miss. I think it has to do with the board inside. And how it depleted .
Open the pack and measure the cell voltage if one is much lower then the rest it must be replaced. Its ok to jump start batteries as it forces the gates to open and juice to charge the cells. If the voltage is 3.3 or more per cell, the charger will accept the battery❤
I also have a Flex dead one, however I only have one Flex. Will try reviving it with some other battery or some sort of 20V source. Also have a Greenworks just out of Warranty that died!!
Some chargers can charge different types of batteries. LiPo batteries can be boosted to above the cut off level of the charger by charging for a few seconds on one of other settings. I don't remember if it was NiMH or NiCd that I used to do this. But it worked.
Thanks, I will try it! Success might be based on forcing the suspect battery to take a charge using another battery rather than an electronic DC circuit (i.e. the charger). As an example, note how much quicker you can charge a weak phone battery from a sizeable battery vs even the supposed strongest wall chargers.
This problem is known by the manufacturer and would be easy to fix with a spring pressed bypass switch. The only problem is that the manufacturer has a cash incentive to have people throw away the good packs. The problem protection circuit has been around since 2004, at least. The battery has a built in protection circuit against heat, too much current, over charge and under charging (too low can cause dendrites). The charger is worried about unprotected, overly drawn down cells. A tripped battery circuit has a zero charge too boot, so the charger won't charge it. It makes carrying around protected lithiums and a smart charger a pain, because now you need jumping equipment to operate.
Can't wait to find out if the battery holds up since it was dead, dead beforehand. I certaily understand why it worked. But it is odd the battery being new and dead like that suggest there is an issue that may still exist. Cool video none-the-less.
I've had to do that a couple of times to one of my cheap 18 volt 6ah battery for one of my vacuum batteries that goes dead sitting on the Charger when I forget. I usually use some old speak wire as I can't find the jumper wires with alligator clips on them. The older nicad batteries you can pop open the case and test each cell individually and you can hit them with jumper wires with a 12 volt car tail light to take down the load and voltage. You jump the dead cell for about a count of 5 and test to see if the voltage came up over a volt. If it has you've burned the internal buildup that kills the cell. If not you can try it again just be sure not to overheat the cell or bad things happen. I haven't done that one in years but i managed to get some old Dewalt 18 volt XRP drill batteries working for at least another 6 months and about 3 of the cells were dead when I started. I'm sure there are older videos out there about doing this but there are a lot of variations. Since older drill batteries are so cheap now I usually just buy some knockoffs and use my drills again now and they usually are lithium that works way better except for the sitting too long and not charging solution you just posted.
Good tip. I'll have to try this when one of my batteries dies. I would be afraid of damaging a good battery so I would just hook it to my power supply set to 20V or whatever.
That’s pretty awesome. I have a couple batteries that charge, but as soon as you take them off the charger, they no longer show as full. One of them immediately shows one bar, and the other 3 out 4 bars. They were accidentally left out in extreme temps. I don’t think there’s anything I can do short of taking out individual cells and replacing them or just replacing the whole thing. Oh well, live and learn I guess.
I had a fully charged Powerstack Dewalt battery that died, I only used it once and it was a few months old. Had no damage. I tried this and it didn't work :(. DeWalt did honor the warranty though.
This is a common thing with the li-ion batteries when their charge drops below a certain level. The chargers are set to not charge a battery that is bellow that level of charge. I think it's meant to be for safety, e.g. said battery may be more likely to develop an internal short and catch fire, or so I've heard. However, yes it's often able to be recharged if you can bring it's charge back above a certain level
The charger has a voltage sensor. It won't charge a "Dead" battery but using this trick it force charges the dead battery so it has some charge. THEN the charger sees a charge on the bad battery and starts charging it. I made a device from old parts that allows me to connect Lithium batteries together much like the razor blade example. It works fine.
DIY HVAC GUY has some great tips! Great video to start the year. Surely (don't call me Shirley) you can put some more chargers up. I see plenty of empty woodage. Happy New Year Clint!!!
Any hvac guys with diy in their name is a good sign to stay clear from and not take advice from .. coming from a hvac guy, I've seen what diy does and causes 😂😂
My only concern is when a lipo does that and you bring it back to life it may become unstable although you may bring it back to operational status there are risks people need to be aware like an unbalanced cell which may cause a fire later down the road. I believe manufacturers do that to insure that doesn’t happen however this will work on a pinch. This is why I never buy used batteries cause you never know
Unbalanced cells can occur whether or not the entire pack is over discharged, and the BMS should be helping mitigate the differences, but the risks you are talking about are real in that the already existing differences in cells could be made worsened with more damage from over discharge, but the alternative would be to throw a functioning battery away. If already at the end of it's life, recycling the battery is reasonable, but a battery that is a year or two old probably has a lot of life left. I've rarely encountered this problem personally, because I try to aways keep my batteries at least partially charged. But when I've attempted to revive a battery it is with a DC power supply. Anyone with a lot of power tool batteries and reasonable aptitude should probably learn how to use one.
@@Rickmakes If charging a discharged battery, charging it slowly and avoiding charging at low temperatures are 2 things to help mitigate dendrite formation
@@sidewinderam9m "there is no BMS in most major manufacturer chargers." The BMS is most often in the battery packs themselves, and chargers usually have a more limited monitoring that runs along a spectrum but usually not a true BMS. But what is your point? Whether it exists in the charger, or battery there is little difference unless you are bypassing it (which is being done to a limited extent with certain adapters or this razor blade thing in the video)
The BMS board in the battery is your safety net to prevent your battery from burning down your house... j/k. LOL. when you drain the crap out of your battery too low. the BMS shuts the whole battery pack down. till you "wake it up" like how you did it. applying some voltage to wake up the battery.
Thanks for another kinda nass like video Clint! Also thank you for allowing Ryobi not REEobi, to retain its dignity. . .so many bat-ray repair videos use Ryobi not REEobi in their videos when they perform these warrantee breaking surgeries. . .as an example. . .the societal pariah. . .always, exploited. . .made fun of. . .but you my friend, took a stand! You said "I am going to show them with this flex bat ray that. . .on the inside. . .we are all similar!" 🤣 Thanks for another great video!!! one for the algorithm!
Battery charges have a polarity tester and a dead battery has no polarity. So, by jumping battery to battery you reestablished the polarity so the charger could detect the battery's polarity.
You need to make sure the batteries you're doing this with are the same voltage. You're essentially forcing the charged battery to balance with the dead battery. I assume the charger doesn't work because the battery has fallen below the acceptable voltage to begin charging(and that low of a voltage likely damages the battery and permanently reduces capacity).
Oh dear lord. This is a really good way to destroy a battery or two, or potentially cause a fire. When your battery drops below a certain voltage, often when you haven't used it in a while, it's internal battery management system can leach a small bit of power and eventually drain the battery below a threshold where the charger says "nope, it's defective". This is done for a reason, because if the individual cells drop below 2.8V, they start to break down and start causing the internal resistance to rise. This will shorten the life of the cell and increase its chance of heating to a point where it catches fire in a rather spectacular fashion. The best way to do it is to get a specialized charger that recognizes when a pack is low, and give it a mild charge rate, less than a tenth of it's designed rate, until it goes above the threshold and the charger will recognize it and charge it normally. The razor blade method is just dumping current as fast as it can, and that can damage both batteries. If you're in a pinch where you need two battery packs, this may work, but it comes with a cost.
Correct, but in the real world, the battery protection on the battery trip all the time, making you battery not charge. In reality, no such dendrite or other short risk exists. In theory, an unprotected lithium is lsd. The protection circuit is a parasite that sucks down the battery. But the circuit itself protects the cell from being drawn down below the dangerous voltage. My lithium 18650s, even my panasonic 3400s, have seemed to be limited to 3 years, which seems to be the shelf life for the liion chemistry. Same with the laptop chemistry. My phone batteries seem to be barely usable in 1 year and dead in 2, because a phone draws an average of an amp during real world use, and the cells are between 3 and 5400 amp hours. My navigation, bright screen need, and need for lots of photos and video, plus audio player, macros, spoken notifications, web searches, constant incoming calls and texts, constant ringing and vibration,... Etc. I use between 8 and 12 amp hours from as early as 5 am to as late as 12 pm. So, my phone batteries last about a year.
I have been building time-lapse camera boxes since 2017. I switched to the lithium 12 v batteries as the power supply. I need to jump that battery nearly every charge if I do not keep the cam box constantly on the charge by plugging in the box cord. 😂
Also I believe that drill and 12v battery packs are lifepo4. LiFePO₄ batteries exhibit superior resistance to internal shorting under low voltage conditions compared to many other lithium-ion chemistries. Their inherent chemical and thermal stability, combined with structural robustness and safety features, make them a preferred choice in applications where safety and longevity are paramount. However, there is always a maybe and the door is always open to the possibility of a rare event. I could be wrong, and invite you refute. Not wedded to my current understanding. I am interested in the whole truth.
I have been doing this for years. I just use 2 pennies instead of razor blades. My older Makita batteries dont have internal bms so nothing stop them from over discharging. Works just like jumping a car
Thats old news just put the battery in the charger and pull it out do this a few times its like a bump charge and your battery will charge I figured that out 15 years ago😂
Just so's you know you should NOT do this. Unlike any other batteries, Lithium Ion batteries are damaged the moment they discharge below their "cut-off" voltage. The BMS inside the pack is supposed to prevent this from ever happening. If it does happen, it's supposed to prevent further charging of the damaged cell or cells. If a cell drops below that model cell's cut-off value the cell will never hold as much energy as it used too. This causes the pack to become flaky and problematic going forward. Worse, the cell is now many times more likely to catch fire during charging. If you want to play roulette and opt to try and get more use out of the pack, more power to you, but, restrict charging it to low value locations and always under supervision. Charge it outdoors and not in your shop while you're not present.
LiFePO₄ batteries exhibit superior resistance to internal shorting under low voltage conditions compared to many other lithium-ion chemistries. Their inherent chemical and thermal stability, combined with structural robustness and safety features, make them a preferred choice in applications where safety and longevity are paramount.. See my other post for more reasons why this might not apply, as it does for our beloved lithium ion cells.
They could become damaged, especially if they sit in discharged condition. They start moving copper ions and form dendrites inside similar to neglected NiCd batteries. If you have a dead one then charge at a higher voltage but lower current till the cells reach 3.4V then let sit. The cells that go flat must be replaced. ❤
Waking up the BMS so the battery can take a charge again. Cells rarely fail. It's usually that the BMS dies or like here, just needed to be activated. Good as new, maybe. Like most all other chemistries, letting lithium sit in a dead or too low state of charge without management can be detrimental to the cells over time.
You should always do the positive connections first and then the negative. Similar as to a car battery. Not trying to nit pick as it didn't make a difference in this case but its a good habit to get into. But awesome trick!! Thanks!
It doesn’t matter at all. This is from when car batteries produced a lot of hydrogen gas when charging, and you wanted to avoid sparks near the battery. Then you put the charging/jump start wires in that order. With the negative fear from the battery. This doesn’t apply to these kind of batteries, or any modern batteries.
@@jesperwall839 This may be part of it, but the biggest reason is if you unhook positive first and your wrench swings and hits metal inner fender, then you are arc welding. If doing negative and wrench slips into something metal, no big deal.
With these it doesn't matter, believe it or not these tool batteries and all other lithium ion batteries regulate the negative side. For this reason smart chargers for lead acid batteries self destruct if hooked to a 12V lithium ion battery pack. 😮
Some batteries have reverse charge protection, especially flex voltage types. But the problem occurs when you put away a battery with minimum charge and not use it for a while. After time the battery charge drops below the minimum and the circuitry will not permit it to charge beyond that point, thus it appears to be dead. There is a way to revive these batteries but it involves dissasembly of the pack and force charging (after testing) individual cells to boost the pack to an acceptable level for the charger to take over. This can be dangerous though, best to have it done by someone with experience. The best practice is when you use your battery to the point it stops working don't toss it on the bench and grab a different one. Take a mi ute to put it on a charger evev if its for 15 or 20 minutes. That will put enough charge in it to last for months without dying. I don't know why they won't build chargers that can indicate when the state of charge reaches 80 to 90 percent. This the ideal range for batteries to last much much longer. There are many TH-cam videos on how to care for the batteries to make them last so much longer. Also, you get what you pay for, i have found so many low end power tools that claim to have batteries with a rating of 2ah when in fact its lucky to be 1ah fro😂m the factory. They will work just fine and if properly treated will last a fairly long time if properly charged before putting them away. Buyer beware. Good luck friends.
Generally, a modern battery like that shouldn't get reverse voltage error, but too many people learnt things from charging the first single cells from the late 80s/early 90s. They were told about battery memory, which WAS a thing. So, they still completely flatten their batteries so they don't develop a memory point. Problem is, not all the cells in the battery will get to zero charge at the same time, and if one hits zero, and the current left in the others is still high enough, it can flip the voltage of that cell, essentially locking it. The charger detects the fault, and won't charge so it doesn't burn your house down. Yes, this trick works on all batteries. Best way not to need it, is never run the battery completely flat. Run down to a single light, and recharge then. The cells will NOT get a memory like old time rechargeables. Completely different chemistry. The chemistry in the batteries does eventually break down, which is why batteries now days start to hold a charge less. It's not charge memory. Now, if you have single cells like D, A, AA, etc, there is a similar way to reset them. Find a fully charged cell, and place it base to base with he faulty one. Then, with the pointy ends out, short out those points. (Using metal tongs works well for that.) Hold for about 5-10 seconds, then see if the faulty one will charge. If not, try again. After the third try, if it doesn't start to charge, the chemistry is shot, so dispose of into battery recycling.
This is basically bypassing the little computers that think they're smarter than you. I have made jumper wires with pin connectors for this. If I run a battery dead out in the field and then the cold weather drains the last little bit of recognition from it, the charger won't even do anything.
Can Confirm!!! And it will work with ANY batteries, including Ryobi. And if you are not able to get it to boot, then it still may be fixable. Msg me if you'd like to learn how, and you can try it for another video. 😉🔥🔥🔥🔥
This trick has been circulated on the internet for several years by different people. I haven't needed to do it, because I am always careful to not let them run down that far. From what I understand, the cause of the charger not working is how it is made to sense a certain amount of minimum life left in the batteries. If the battery falls below a certain range, the charger will not work. I don't know why they're made that way, but possibly to fool people into buying new batteries. As for not overusing your batteries, you should be able to tell when they are about to quit. You should be able to know because the tool will start losing power, and sometimes sound different.
I'm just going to start making videos of how to diag these correctly. Its so damn simple to pull these apart and make sure you aren't wasting your time first. $10 multimeter and 4 screws
Here is the science: The charger has an electrical circuit that monitors the to-be-charged battery voltage. If that measurement is too low from the battery then the charger turns off the charging. When you jump the low voltage battery, you raise the battery voltage just enough so that when placed on the charger, the charger allows the charge cycle. The reason the battery won’t charge is in the charger not the battery. It is a safety issue for Lithium batteries.
I think what it does is balance out all the batteries in the dead one enough to where they will charge. Wish I would of tried on that ryobi I got rid of.
I have 2 skill batteries, positive positive, negative negative, and I just melted the connectors I don't know what went wrong one battery was completely dead. And the other one was good now they're both fried 😢
"Smart" charging circuits will not attempt to charge a battery which it perceives as faulty when connected. The safer approach is to connect these battery contacts to a transformer of same or just slightly higher voltage than the rated battery voltage and amperage higher than that of the smart charger, and force it to charge for an hour to revive it to the point that the smart charger will work again. I've seen this done in electric scooters with $300 battery packs. Jump starting from another battery is not good for either battery. Too much amperage.
The smarts in the battery charger has recognized that there is 1 or more faulty cells, in the battery pack. What you have done is to force a charge (by equalizing the 2 battery packs, by shorting them together), this will force the faulty cell to a voltage above the threshold (of what the battery charger accepts) and so the battery will now charge. Make no mistake, you have a battery pack with a faulty Cell, it might continue to work well (just keep the battery topped up and do not let it go uncharged for an extended period), or one day the battery charging could reverse charge the faulty cell and the result will be a small explosion and a toxic fire. You should add a warning to your video, so that people are warned and make a conscious decision to attempt this.
That's not what happened. The newer rapid chargers don't recognize the battery if it's completely dead like this. Would have been fine on a standard charger
Okay here is why this works lithium ion batteries must be charged correctly you really can't safely use a dumb charger on a lithium ion battery on top of that there's different chemistries lithium-iron lithium ion lithium polymer and there's a couple others as well and if you charge the wrong battery the wrong way well you've seen phones and cars blowing up things get very energetic very quickly as in burn down your house kind of energetic The problem is actually the same as the problem you have with car battery chargers you notice the new car battery charger sometimes they just won't charge your battery because it's too dead you need a dumb charger or you need to hook up a jump box to it to trick the charger into charging That's what you're doing here basically the battery voltage is too low and the BMS circuitry has cut off the charging circuit this is to protect the battery from a further discharge however the problem is now you can't charge it because the charger has smarts in it and it starts to analyze the battery and it can't get nothing because it's disconnected it's not really but I mean simplifying this so what you're doing is literally jumping the battery when you plug the one battery into the other the two batteries are going to try to equalize think of it like hot and cold if you put something hot next to something cold the energy from the hot side goes to the cold side until both sides are the same temperature this lowers the temperature of the hot side raises the temperature of the cold side until they equalize When you jump the battery with the other battery you are raising the voltage above that minimum threshold for the dead battery now when you plug it into the charger the circuitry can see what it expects to see it can analyze that okay this is the right battery now I can begin charging That's what you're doing that's all you're doing if you want to do this safer you can buy little caps that go on the battery and have just two wires coming out of it this is to allow you to power other things using your tool batteries well buy two of those use some heat shrink and solder together the red and the black wires to the red and the black wires and you now have a double ended battery cap plug the good battery in the bad battery into that and now you don't have to use razor blades and open circuit connections just don't do it too long because the Delta between the batteries is pretty high meaning the good battery is going to work pretty hard to try to equalize that bad battery although power tools are made for high loads so it's probably fine but a couple of minutes should be enough sometimes even 30 or 40 seconds is enough just to put just a little bit of juice back into the battery so the charger can see it properly and then it can initiate the charge
Hey yo Bad Santa Clint i wish you and your family a wonderfool happy new year and i hope somebody gives you and electric or cordless heater for that garage🥶😂🤣
Alien technology! 😂 Seriously, though. That's a one-time fix. It will go back to bad after 1 or 2 uses. At least that's what happened to me back in the days of NiCd batteries after doing a jump start on a bad battery pack. However, i can't speak to Lithium-ion. Keep us posted on the condition of the bat ray! 😎🎸👍
This does work but you need to know what you are doing. One, razorblades is not a good idea. they are too thin and if you do not insert it all the way, they might get heated. Better use a small piece (2x1cm) of copper sheet of 1mm+ thickness soldered to ends of a wire. This method might cause batteries to heat up and catch fire. This could happen to the good side as well. Be prepared. Do not leave batteries unattended during this time. A better technique would be to take out the cells and use a charger that will not check for low voltage. This will prevent further damage on batteries too as chargers will adjust the charging voltage as needed, lithium batteries are very finnicky with their charging voltage, they don't explode unless it is too high but they will get damaged easily. Any of these techniques will not bring battery back to the state before the event, a li-ion battery fallen below 3.2V would have capacity issues. How far and long determines how badly it would be damaged, but its capacity will not be 100%. This also depends on battery chemistry, LFP batteries will have minimal damage while some others will loose most of their capacity.
Chances are that battery’s not gonna be very good. Just like mini jump starters you have to have some voltage in the car battery in order for a charger to work. Many of the trickle chargers work the same way. You have to put a little voltage in the battery or it will not start charging. Your battery was completely dead and since lithium batteries do not like to be completely dead. That battery will probably not run your drill for very long before it dies.
Kinda like when your new fangled automotive battery charger says “sorry but this battery is dead and I will not be part of any further efforts.” But the crusty old analog charger from the 70’s say “hold my solo cup”.
The only reason the Dumb charger works instead of the new Smart charger is...because it's to dumb to know it's not supose to...🤔 🤪
That's why I keep my analog charger from the age of the dinosaurs. When my battery was completely dead (from leaving the dome light on all night), the breaker popped a couple of times and then it charged the battery and I'm still using that battery years later.
“Hold my solo cup” 😂! ….after the new charger has peaced out with a hard seltzer 😁
People have been doing this for a long time for lithium batteries with BMS boards in them. The reason this works is because there is a set low voltage cut-off on the board. Usally 3.2v per cell. If the voltage drops below that set voltage (from sitting a long time, or a bad cell) it will not take a charge because the BMS isn't going to allow it. So by using another battery you can raise the cell voltage up pass 3.2v (each cell) and then the BMS allows the charger to charge the battery.
I believe part of it also is that all the name brand lithium batteries have to have a “handshake” with the charger and the low voltage doesn’t let the battery tell the charger it’s still good.
Absolutely 💯 correct
We have lifepo4 batteries on our boat and returned to the boat after a month and found them "dead" (forget what incredibly stupid thing we did to cause this).
Anyhoo... The charger (when we turned on the shore power) would not charge them. The engine's alternator, however, didn't care how dead they were. We ran the engine for 5 minutes or so and it gave them enough juice to allow the charger to finish the job. Thereafter, they were fine charging off shore power.
I wish I had just read your comment instead of spending 5 and a half minutes watching the video. Thanks for the explanation.
Whaaaaat! I had a 12ah Miwakiah batray that arrived doa. Unfortunately I opened it a month or two after arrival and lost the receipt. I held on to it because I did not know how to dispose of it. I have stared at that batray with the evil eye for over a year. Now, with your video, it is alive!
This won't fix every battery but if conditions are favorable, there's a solid chance for it to work. The issue being fixed by jump starting like this is the overall batt pack having too low a voltage for the charger to recognize it as 'safe to charge'. So you're just giving it a little boost to increase the voltage for the charger to say, 'yeah, it's safe'. This won't work if there's a cell in the pack that has or is failing altogether. That's the stage where you'll need to take the pack apart, find the bad cell, and replace it w/an identical replacement if you can. Lots of vids showing that process.
That's exactly how I found out I had a dead / dying cell in my milwaukee battery
As a RC enthusiast I agree and have experienced that in the hobby with lipo batteries often.
@@cwatson42785good point, I bet this also could be done on a hobby charger 🤔
@@marsbase3729 Yeah I was wondering that as well lol. I'm sure there would be a way to strip some 4mm bullet wires on the charging end and hook it up. Plus you could put it on a really low amp charge to charge it really slow to help the chances to restore the bad/low cells.
What also works is to put the charger on a surge strip and keep turning it off and on - gives that little spike needed to start charing again!
Interesting.... ima try it!
@@ToolReviewZone Lettuce know if it works.
Let's hope it's not "charing"😂
I do not understand what you mean. A surge protected power strip is alternating current and 120 v. A battery pack is 3.7 to 40v DC. Special wires would be needed and the protection circuit principle is not followed
@dennisgarber you plug the dead battery on the charger - plug the charger into a surge protector with a on off switch. Turn on wait a second turn off - keep repeating for a minute
Totally works..manually forces juice into a completely dead battery, which needs a tiny bit of reserve to communicate with the charger.
This can also be done with a couple of leads and a portable battery charger.
Did it to save a Flex battery last year.
I tried this on a Ryobi (not Reeobi) 2ah batry and it worked great.
Ah...but will it work on a BATTERY?😂😂😂😉
Ryu in Japanese is “reeoo”
@@goro2k I named my Shihtzu dog Ryuu, pronounced reeoo (cute dragon) who's also my profile pic
OMG !!!!! I have to try that. I have three Bosch batteries with the same problem. Thanks Clint !!!! You might have saved me a bunch of money.
That's would definitely be real nass like brother. Let me know 👊
@@ToolReviewZone Hay bud, I got one back to live of the three. You saved me $70.00. Thank you !!!!
@stephenleepmg113 that's awesome. Glad it helped brother
Greetings from sunny Cape Town South Africa 🇿🇦
Just tried this on a dead Ryobi 18V and it actually worked. Busy charging. Spank Ya ( thank you)
Not going to lie, I haven't watched your vids in awhile and was even unsubscribed. This one happened to pop up and I had a milwaukee battery that was dead and I was needing to try and warranty. Just tried this and it is now on the charger coming back to life. Subscription earned.
Nearly everyone already knew this but its great to see how excited someone gets, like this guy, when its discovered. This trick has been popular for the last decade or more with lithium battery jumpers that wont charge once they go below a certain voltage. Just jumping them with another battery usually brings them right back.
No, not nearly everyone. Most people don't know this
Found your channel recently and enjoy it muchly! Thanks for the info-tainment!!
Cheers from Canada!!
My brother I thought you knew that trick or I would’ve told you. I’ve used small pieces of wire too. This has saved my bacon a time or two!! Great vidja as always!!
the "dead" battery has a very low charge, the charger requires a minimum charge in a battery in ir order to "see" it.. jumping it with the good battery brings it up to that minimum .. I successfully revived an old ryobi nicad using a 13 volt dc power supply
Exactly bud
I have fixed a couple of Ryobi batteries in a different manner. I took them apart and found the low cell using a dvm and brought it up to the correct voltage using a variable bench dc power supply with current limit. They have worked for years after this fix. One I couldn't fix because the battery had a negative voltage on one cell. I to fix that I would have had to purchase or manufacture a cheap spot welder for nickel strips so I can replace the defective cell. At that point I gave up because it was only 1 battery.
I've been doing this for years. Back then, a friend showed me how to jump-start a dead 0% battery. It was a dumbfounded moment, like how we know how to jump-start a car but never thought about other batteries.
I have been using this technique for a good while. Certain conditions are required though. Worked on my Dewalts. Not Metabo at all. Ryobi hit or miss. I think it has to do with the board inside. And how it depleted .
It would be interesting to know why this works.
Open the pack and measure the cell voltage if one is much lower then the rest it must be replaced. Its ok to jump start batteries as it forces the gates to open and juice to charge the cells. If the voltage is 3.3 or more per cell, the charger will accept the battery❤
This video proves the value of TH-cam
Guy was trying to jump-start his Tesla in Las Vegas like this.
🤣🤣
Lol
I guess he missed the bit about not putting the positive to the negative.
Apparently, he used fireworks instead of another battery. Tesla's owner IQ of the year.
Too soon dude lol
I also have a Flex dead one, however I only have one Flex. Will try reviving it with some other battery or some sort of 20V source.
Also have a Greenworks just out of Warranty that died!!
Some chargers can charge different types of batteries. LiPo batteries can be boosted to above the cut off level of the charger by charging for a few seconds on one of other settings. I don't remember if it was NiMH or NiCd that I used to do this. But it worked.
I made me a couple jumpers for my DeWalt Batt when I drain them to low, Works every time
Thanks, I will try it! Success might be based on forcing the suspect battery to take a charge using another battery rather than an electronic DC circuit (i.e. the charger). As an example, note how much quicker you can charge a weak phone battery from a sizeable battery vs even the supposed strongest wall chargers.
i just bought a new battray and it wouldn't charge. tried this before making the long trip back to exchange it and yes it worked
And that's real nass like
This problem is known by the manufacturer and would be easy to fix with a spring pressed bypass switch. The only problem is that the manufacturer has a cash incentive to have people throw away the good packs.
The problem protection circuit has been around since 2004, at least.
The battery has a built in protection circuit against heat, too much current, over charge and under charging (too low can cause dendrites). The charger is worried about unprotected, overly drawn down cells. A tripped battery circuit has a zero charge too boot, so the charger won't charge it. It makes carrying around protected lithiums and a smart charger a pain, because now you need jumping equipment to operate.
Does the battery keep on taking charges or is this just to get you out of a bind once or twice??? Thanks, I have never heard/seen this trick!!!
It is like taking batteries apart and adding a surface charge, this is just a direct method. Nice to know about this hack.
I had a Flex battery literally just do this! I'm gonna try this
Let me know how it works 👊. Flex ain't flexing lately
Can't wait to find out if the battery holds up since it was dead, dead beforehand. I certaily understand why it worked. But it is odd the battery being new and dead like that suggest there is an issue that may still exist. Cool video none-the-less.
I have done this before, works great and that is real nice like
I've had to do that a couple of times to one of my cheap 18 volt 6ah battery for one of my vacuum batteries that goes dead sitting on the Charger when I forget. I usually use some old speak wire as I can't find the jumper wires with alligator clips on them.
The older nicad batteries you can pop open the case and test each cell individually and you can hit them with jumper wires with a 12 volt car tail light to take down the load and voltage. You jump the dead cell for about a count of 5 and test to see if the voltage came up over a volt. If it has you've burned the internal buildup that kills the cell. If not you can try it again just be sure not to overheat the cell or bad things happen.
I haven't done that one in years but i managed to get some old Dewalt 18 volt XRP drill batteries working for at least another 6 months and about 3 of the cells were dead when I started. I'm sure there are older videos out there about doing this but there are a lot of variations.
Since older drill batteries are so cheap now I usually just buy some knockoffs and use my drills again now and they usually are lithium that works way better except for the sitting too long and not charging solution you just posted.
Good tip. I'll have to try this when one of my batteries dies. I would be afraid of damaging a good battery so I would just hook it to my power supply set to 20V or whatever.
That’s pretty awesome. I have a couple batteries that charge, but as soon as you take them off the charger, they no longer show as full. One of them immediately shows one bar, and the other 3 out 4 bars. They were accidentally left out in extreme temps. I don’t think there’s anything I can do short of taking out individual cells and replacing them or just replacing the whole thing. Oh well, live and learn I guess.
Great tip, thank you! It would be interesting to know why this works.
I had a fully charged Powerstack Dewalt battery that died, I only used it once and it was a few months old. Had no damage. I tried this and it didn't work :(. DeWalt did honor the warranty though.
I'm going to try this asap.
On ryobi , you need to take apart and jump the reset button..
This is a common thing with the li-ion batteries when their charge drops below a certain level. The chargers are set to not charge a battery that is bellow that level of charge. I think it's meant to be for safety, e.g. said battery may be more likely to develop an internal short and catch fire, or so I've heard. However, yes it's often able to be recharged if you can bring it's charge back above a certain level
I have to do this all the time with my M12 6.0 batteries so often that I made a set of dedicated jumper wires that I keep in my battery box
The charger has a voltage sensor. It won't charge a "Dead" battery but using this trick it force charges the dead battery so it has some charge. THEN the charger sees a charge on the bad battery and starts charging it. I made a device from old parts that allows me to connect Lithium batteries together much like the razor blade example. It works fine.
DIY HVAC GUY has some great tips! Great video to start the year. Surely (don't call me Shirley) you can put some more chargers up. I see plenty of empty woodage. Happy New Year Clint!!!
Haha, happy new year brother
Any hvac guys with diy in their name is a good sign to stay clear from and not take advice from .. coming from a hvac guy, I've seen what diy does and causes 😂😂
It works with Ryobi also but you have to take the case apart and use the contacts inside.
WOW... thanks for the tip
Oh yes it does!!!! Thanks!!❤
My only concern is when a lipo does that and you bring it back to life it may become unstable although you may bring it back to operational status there are risks people need to be aware like an unbalanced cell which may cause a fire later down the road. I believe manufacturers do that to insure that doesn’t happen however this will work on a pinch. This is why I never buy used batteries cause you never know
Unbalanced cells can occur whether or not the entire pack is over discharged, and the BMS should be helping mitigate the differences, but the risks you are talking about are real in that the already existing differences in cells could be made worsened with more damage from over discharge, but the alternative would be to throw a functioning battery away. If already at the end of it's life, recycling the battery is reasonable, but a battery that is a year or two old probably has a lot of life left.
I've rarely encountered this problem personally, because I try to aways keep my batteries at least partially charged. But when I've attempted to revive a battery it is with a DC power supply. Anyone with a lot of power tool batteries and reasonable aptitude should probably learn how to use one.
Dead cells can grow dendrites that can short the battery.
@@Rickmakes If charging a discharged battery, charging it slowly and avoiding charging at low temperatures are 2 things to help mitigate dendrite formation
@@ccbowersthere is no BMS in most major manufacturer chargers. They will charge even if cells are imbalanced. They will not balance the cells.
@@sidewinderam9m "there is no BMS in most major manufacturer chargers." The BMS is most often in the battery packs themselves, and chargers usually have a more limited monitoring that runs along a spectrum but usually not a true BMS. But what is your point? Whether it exists in the charger, or battery there is little difference unless you are bypassing it (which is being done to a limited extent with certain adapters or this razor blade thing in the video)
The BMS board in the battery is your safety net to prevent your battery from burning down your house... j/k. LOL. when you drain the crap out of your battery too low. the BMS shuts the whole battery pack down. till you "wake it up" like how you did it. applying some voltage to wake up the battery.
Thanks for another kinda nass like video Clint! Also thank you for allowing Ryobi not REEobi, to retain its dignity. . .so many bat-ray repair videos use Ryobi not REEobi in their videos when they perform these warrantee breaking surgeries. . .as an example. . .the societal pariah. . .always, exploited. . .made fun of. . .but you my friend, took a stand! You said "I am going to show them with this flex bat ray that. . .on the inside. . .we are all similar!" 🤣
Thanks for another great video!!! one for the algorithm!
Haha, i actually tried that ryobi battery fix, but didn't work for me 😪
Battery charges have a polarity tester and a dead battery has no polarity. So, by jumping battery to battery you reestablished the polarity so the charger could detect the battery's polarity.
I’m gonna try this on one of my M12 batteries to see if this works! Thanks for the cool things…lol!
Hope it works brother
@@ToolReviewZone me too cause this one is out of warranty…lol!
It will work, and if not, there are 2 other options
Neat trick. I'll have to remember this.
Wow…I tried it with wires for a dead Dewalt battery..I got nothing I don’t think the wires fit..but razor blades…nice
You need to make sure the batteries you're doing this with are the same voltage. You're essentially forcing the charged battery to balance with the dead battery. I assume the charger doesn't work because the battery has fallen below the acceptable voltage to begin charging(and that low of a voltage likely damages the battery and permanently reduces capacity).
Oh dear lord.
This is a really good way to destroy a battery or two, or potentially cause a fire.
When your battery drops below a certain voltage, often when you haven't used it in a while, it's internal battery management system can leach a small bit of power and eventually drain the battery below a threshold where the charger says "nope, it's defective". This is done for a reason, because if the individual cells drop below 2.8V, they start to break down and start causing the internal resistance to rise. This will shorten the life of the cell and increase its chance of heating to a point where it catches fire in a rather spectacular fashion.
The best way to do it is to get a specialized charger that recognizes when a pack is low, and give it a mild charge rate, less than a tenth of it's designed rate, until it goes above the threshold and the charger will recognize it and charge it normally.
The razor blade method is just dumping current as fast as it can, and that can damage both batteries.
If you're in a pinch where you need two battery packs, this may work, but it comes with a cost.
Correct, but in the real world, the battery protection on the battery trip all the time, making you battery not charge. In reality, no such dendrite or other short risk exists.
In theory, an unprotected lithium is lsd. The protection circuit is a parasite that sucks down the battery. But the circuit itself protects the cell from being drawn down below the dangerous voltage.
My lithium 18650s, even my panasonic 3400s, have seemed to be limited to 3 years, which seems to be the shelf life for the liion chemistry. Same with the laptop chemistry. My phone batteries seem to be barely usable in 1 year and dead in 2, because a phone draws an average of an amp during real world use, and the cells are between 3 and 5400 amp hours. My navigation, bright screen need, and need for lots of photos and video, plus audio player, macros, spoken notifications, web searches, constant incoming calls and texts, constant ringing and vibration,... Etc. I use between 8 and 12 amp hours from as early as 5 am to as late as 12 pm. So, my phone batteries last about a year.
I have been building time-lapse camera boxes since 2017. I switched to the lithium 12 v batteries as the power supply. I need to jump that battery nearly every charge if I do not keep the cam box constantly on the charge by plugging in the box cord. 😂
Also I believe that drill and 12v battery packs are lifepo4. LiFePO₄ batteries exhibit superior resistance to internal shorting under low voltage conditions compared to many other lithium-ion chemistries. Their inherent chemical and thermal stability, combined with structural robustness and safety features, make them a preferred choice in applications where safety and longevity are paramount.
However, there is always a maybe and the door is always open to the possibility of a rare event.
I could be wrong, and invite you refute. Not wedded to my current understanding. I am interested in the whole truth.
@dennisgarber most of the battery packs for tools are Li-Ion, I've never seen a LiFePO4 pack for a hand tool.
Wow very cool. Thanks for sharing
Great info!!!!!🎉 thanks
I have been doing this for years. I just use 2 pennies instead of razor blades. My older Makita batteries dont have internal bms so nothing stop them from over discharging. Works just like jumping a car
Holy crap!!! Doing this on two "dead batteries" awesome tip!
Thats old news just put the battery in the charger and pull it out do this a few times its like a bump charge and your battery will charge I figured that out 15 years ago😂
Your razor takes a very strange blade...
WHAAAAAAAAAAA???????????? Omg this is going to save me some money. Thank you for sharing
Just so's you know you should NOT do this. Unlike any other batteries, Lithium Ion batteries are damaged the moment they discharge below their "cut-off" voltage. The BMS inside the pack is supposed to prevent this from ever happening. If it does happen, it's supposed to prevent further charging of the damaged cell or cells. If a cell drops below that model cell's cut-off value the cell will never hold as much energy as it used too. This causes the pack to become flaky and problematic going forward. Worse, the cell is now many times more likely to catch fire during charging. If you want to play roulette and opt to try and get more use out of the pack, more power to you, but, restrict charging it to low value locations and always under supervision. Charge it outdoors and not in your shop while you're not present.
LiFePO₄ batteries exhibit superior resistance to internal shorting under low voltage conditions compared to many other lithium-ion chemistries. Their inherent chemical and thermal stability, combined with structural robustness and safety features, make them a preferred choice in applications where safety and longevity are paramount..
See my other post for more reasons why this might not apply, as it does for our beloved lithium ion cells.
They could become damaged, especially if they sit in discharged condition. They start moving copper ions and form dendrites inside similar to neglected NiCd batteries. If you have a dead one then charge at a higher voltage but lower current till the cells reach 3.4V then let sit. The cells that go flat must be replaced. ❤
@@dennisgarber power tools use Li-Ion batteries
Waking up the BMS so the battery can take a charge again. Cells rarely fail. It's usually that the BMS dies or like here, just needed to be activated. Good as new, maybe. Like most all other chemistries, letting lithium sit in a dead or too low state of charge without management can be detrimental to the cells over time.
Did you get all the juice out of the 5Ah ?
it has lots of gooie sheeet in them
You should always do the positive connections first and then the negative. Similar as to a car battery. Not trying to nit pick as it didn't make a difference in this case but its a good habit to get into. But awesome trick!! Thanks!
It doesn’t matter at all. This is from when car batteries produced a lot of hydrogen gas when charging, and you wanted to avoid sparks near the battery. Then you put the charging/jump start wires in that order. With the negative fear from the battery. This doesn’t apply to these kind of batteries, or any modern batteries.
@@jesperwall839 This may be part of it, but the biggest reason is if you unhook positive first and your wrench swings and hits metal inner fender, then you are arc welding. If doing negative and wrench slips into something metal, no big deal.
With these it doesn't matter, believe it or not these tool batteries and all other lithium ion batteries regulate the negative side. For this reason smart chargers for lead acid batteries self destruct if hooked to a 12V lithium ion battery pack. 😮
Some batteries have reverse charge protection, especially flex voltage types. But the problem occurs when you put away a battery with minimum charge and not use it for a while. After time the battery charge drops below the minimum and the circuitry will not permit it to charge beyond that point, thus it appears to be dead. There is a way to revive these batteries but it involves dissasembly of the pack and force charging (after testing) individual cells to boost the pack to an acceptable level for the charger to take over. This can be dangerous though, best to have it done by someone with experience. The best practice is when you use your battery to the point it stops working don't toss it on the bench and grab a different one. Take a mi ute to put it on a charger evev if its for 15 or 20 minutes. That will put enough charge in it to last for months without dying. I don't know why they won't build chargers that can indicate when the state of charge reaches 80 to 90 percent. This the ideal range for batteries to last much much longer. There are many TH-cam videos on how to care for the batteries to make them last so much longer. Also, you get what you pay for, i have found so many low end power tools that claim to have batteries with a rating of 2ah when in fact its lucky to be 1ah fro😂m the factory. They will work just fine and if properly treated will last a fairly long time if properly charged before putting them away. Buyer beware. Good luck friends.
Generally, a modern battery like that shouldn't get reverse voltage error, but too many people learnt things from charging the first single cells from the late 80s/early 90s. They were told about battery memory, which WAS a thing. So, they still completely flatten their batteries so they don't develop a memory point. Problem is, not all the cells in the battery will get to zero charge at the same time, and if one hits zero, and the current left in the others is still high enough, it can flip the voltage of that cell, essentially locking it. The charger detects the fault, and won't charge so it doesn't burn your house down. Yes, this trick works on all batteries. Best way not to need it, is never run the battery completely flat. Run down to a single light, and recharge then. The cells will NOT get a memory like old time rechargeables. Completely different chemistry. The chemistry in the batteries does eventually break down, which is why batteries now days start to hold a charge less. It's not charge memory. Now, if you have single cells like D, A, AA, etc, there is a similar way to reset them. Find a fully charged cell, and place it base to base with he faulty one. Then, with the pointy ends out, short out those points. (Using metal tongs works well for that.) Hold for about 5-10 seconds, then see if the faulty one will charge. If not, try again. After the third try, if it doesn't start to charge, the chemistry is shot, so dispose of into battery recycling.
This is basically bypassing the little computers that think they're smarter than you. I have made jumper wires with pin connectors for this. If I run a battery dead out in the field and then the cold weather drains the last little bit of recognition from it, the charger won't even do anything.
how would you do a ryobi... ??
Clint, if you put the battery on and off the charge several times the same thing will happen and the battery will come back to life okay.
Definitely going to try it brother
Can Confirm!!! And it will work with ANY batteries, including Ryobi.
And if you are not able to get it to boot, then it still may be fixable. Msg me if you'd like to learn how, and you can try it for another video. 😉🔥🔥🔥🔥
Have u try it in
This awakens the state to recharge. you can do this with other rechargeable lithium batteries such as size A, C D, etc..
This trick has been circulated on the internet for several years by different people. I haven't needed to do it, because I am always careful to not let them run down that far. From what I understand, the cause of the charger not working is how it is made to sense a certain amount of minimum life left in the batteries. If the battery falls below a certain range, the charger will not work. I don't know why they're made that way, but possibly to fool people into buying new batteries. As for not overusing your batteries, you should be able to tell when they are about to quit. You should be able to know because the tool will start losing power, and sometimes sound different.
Will it work with EGO?
It should
What was that about Ryobi?
What's a bat Ray?
I'm just going to start making videos of how to diag these correctly. Its so damn simple to pull these apart and make sure you aren't wasting your time first. $10 multimeter and 4 screws
Very 🥶cool Cliff!👍🏻🇺🇸
Here is the science:
The charger has an electrical circuit that monitors the to-be-charged battery voltage. If that measurement is too low from the battery then the charger turns off the charging. When you jump the low voltage battery, you raise the battery voltage just enough so that when placed on the charger, the charger allows the charge cycle. The reason the battery won’t charge is in the charger not the battery. It is a safety issue for Lithium batteries.
how do you do this with a ryobi? Ryobie has a stem!
I said the same thing in the video. Couple commenter's saying they did it though 🤷
Ryobi batteries from back in the day did this to me.
I think what it does is balance out all the batteries in the dead one enough to where they will charge. Wish I would of tried on that ryobi I got rid of.
You can also use a 9v battery.
I see a future market for battery charging cables.
I have 2 skill batteries, positive positive, negative negative, and I just melted the connectors I don't know what went wrong one battery was completely dead. And the other one was good now they're both fried 😢
Not even sure how that would be possible
@@ToolReviewZone use a volt meter to check if you should try this before going full send.
What kind of wizardry is this 😮
"Smart" charging circuits will not attempt to charge a battery which it perceives as faulty when connected. The safer approach is to connect these battery contacts to a transformer of same or just slightly higher voltage than the rated battery voltage and amperage higher than that of the smart charger, and force it to charge for an hour to revive it to the point that the smart charger will work again. I've seen this done in electric scooters with $300 battery packs. Jump starting from another battery is not good for either battery. Too much amperage.
terrible audio mix.
The smarts in the battery charger has recognized that there is 1 or more faulty cells, in the battery pack. What you have done is to force a charge (by equalizing the 2 battery packs, by shorting them together), this will force the faulty cell to a voltage above the threshold (of what the battery charger accepts) and so the battery will now charge. Make no mistake, you have a battery pack with a faulty Cell, it might continue to work well (just keep the battery topped up and do not let it go uncharged for an extended period), or one day the battery charging could reverse charge the faulty cell and the result will be a small explosion and a toxic fire. You should add a warning to your video, so that people are warned and make a conscious decision to attempt this.
That's not what happened. The newer rapid chargers don't recognize the battery if it's completely dead like this. Would have been fine on a standard charger
NOW THAT'S REAL NICE LIKE ❤❤❤❤❤
Okay here is why this works lithium ion batteries must be charged correctly you really can't safely use a dumb charger on a lithium ion battery on top of that there's different chemistries lithium-iron lithium ion lithium polymer and there's a couple others as well and if you charge the wrong battery the wrong way well you've seen phones and cars blowing up things get very energetic very quickly as in burn down your house kind of energetic
The problem is actually the same as the problem you have with car battery chargers you notice the new car battery charger sometimes they just won't charge your battery because it's too dead you need a dumb charger or you need to hook up a jump box to it to trick the charger into charging
That's what you're doing here basically the battery voltage is too low and the BMS circuitry has cut off the charging circuit this is to protect the battery from a further discharge however the problem is now you can't charge it because the charger has smarts in it and it starts to analyze the battery and it can't get nothing because it's disconnected it's not really but I mean simplifying this so what you're doing is literally jumping the battery when you plug the one battery into the other the two batteries are going to try to equalize think of it like hot and cold if you put something hot next to something cold the energy from the hot side goes to the cold side until both sides are the same temperature this lowers the temperature of the hot side raises the temperature of the cold side until they equalize
When you jump the battery with the other battery you are raising the voltage above that minimum threshold for the dead battery now when you plug it into the charger the circuitry can see what it expects to see it can analyze that okay this is the right battery now I can begin charging
That's what you're doing that's all you're doing if you want to do this safer you can buy little caps that go on the battery and have just two wires coming out of it this is to allow you to power other things using your tool batteries well buy two of those use some heat shrink and solder together the red and the black wires to the red and the black wires and you now have a double ended battery cap plug the good battery in the bad battery into that and now you don't have to use razor blades and open circuit connections just don't do it too long because the Delta between the batteries is pretty high meaning the good battery is going to work pretty hard to try to equalize that bad battery although power tools are made for high loads so it's probably fine but a couple of minutes should be enough sometimes even 30 or 40 seconds is enough just to put just a little bit of juice back into the battery so the charger can see it properly and then it can initiate the charge
Hey yo Bad Santa Clint i wish you and your family a wonderfool happy new year and i hope somebody gives you and electric or cordless heater for that garage🥶😂🤣
Lol
This is called "Equalizing" bc the batteries charge falls below what the charger detects.
Very cool!
Alien technology! 😂
Seriously, though. That's a one-time fix. It will go back to bad after 1 or 2 uses. At least that's what happened to me back in the days of NiCd batteries after doing a jump start on a bad battery pack.
However, i can't speak to Lithium-ion. Keep us posted on the condition of the bat ray! 😎🎸👍
I hope that's not the case, but will definitely keep you updated brother
I'm 1st my friend and that's realnicelike 😊
That is real nass like brother!!!
This does work but you need to know what you are doing. One, razorblades is not a good idea. they are too thin and if you do not insert it all the way, they might get heated. Better use a small piece (2x1cm) of copper sheet of 1mm+ thickness soldered to ends of a wire.
This method might cause batteries to heat up and catch fire. This could happen to the good side as well. Be prepared. Do not leave batteries unattended during this time. A better technique would be to take out the cells and use a charger that will not check for low voltage. This will prevent further damage on batteries too as chargers will adjust the charging voltage as needed, lithium batteries are very finnicky with their charging voltage, they don't explode unless it is too high but they will get damaged easily.
Any of these techniques will not bring battery back to the state before the event, a li-ion battery fallen below 3.2V would have capacity issues. How far and long determines how badly it would be damaged, but its capacity will not be 100%. This also depends on battery chemistry, LFP batteries will have minimal damage while some others will loose most of their capacity.
I have a buddy with a dead pc battery that was essentially new. I bet this is whatbhappened! I just asked him if he threw it away. Hopefully not.
Chances are that battery’s not gonna be very good. Just like mini jump starters you have to have some voltage in the car battery in order for a charger to work. Many of the trickle chargers work the same way. You have to put a little voltage in the battery or it will not start charging. Your battery was completely dead and since lithium batteries do not like to be completely dead. That battery will probably not run your drill for very long before it dies.