My Makita impact drill battery would not charge, after being left flat for six months, and I tried fitting and removing it rapidly from the charger repeatedly in quick succession to 'reset the chip' but this did not work. So, after watching your video Scooby Rolla I did not have a second battery to use as you have done, so I used an old 16V, 0.5amp charger which I had lying around home from some unknown appliance or radio long gone from my home, and I stripped the two wires coming out of the charger and hooked them to the dead Makita battery for about an hour and then tried the battery in the charger. Bingo, the battery charged right up to full, and now I don't have to do anything further to it. Your video made me try this idea, and it worked. Thanks very much.
superb just rebooted my battery by connecting an external power supply at 10V 2A to + and -. Took about 1 min to get enough juice in it to then allow the charger to see it. This is so simple thanks so much. Significantly easier than rescuing a drone battery !
Awesome I jumpered my Ryobi 3ah to it for about five minutes and bam 9.6 to 18 something volts. The reason for my voltage drop was years between charges while in storage. Charges now, thank you so much!
So glad I could help & thank you for the feedback. I think we are one of the lucky ones who didn’t have battery leaking acid or circuit board damage in the battery. Thank you for watching I really appreciate it. Hope you’re having a great day
There's a safety chip inside de battery that breaks when the power goes bellow the limit, you have to dismantle the battery and bypass a safety chip by soldering a wire to fool the charger There's a video in spanish in RUclips that will teach you how to do it You just type in the browser "Como reparar una batería makita" You might need someone to translate But it's pretty simple you should be able to know what he is doing and how to do it even if you dont speaks spanish
I used a solar panel and 14/2 gauge Romex Home wireing harness +/- to re-charge a previously bricked Makita 18 Volt Battery. Then the Makita Charger's micro processor agreed to charge the previously Bricked18 Volt Makita Battery to fully recharge thar Bricked 18 Volt Makita Battery. Then I used the previously Bricked 18 Volt Battery and was able to recharge the Makita 18 Volt Battery again :). Thank you !
Definetely going this a try, have 3 "dead" batteries hoping to revive.. Loved your comments in the video, it was a pleasure watching.. Even if it doesn't work for me I had a good time watching ;) Cheers
Thanks curtis so glad I could help & really happy it worked for you. Thank you so much for the positive feedback & thank you for watching. Hope you are having a great day
What did you use to bridge both batteries? I tried using a battery used to jump start car and that didn't work (used copper to connect positive and negative to respective terminals)
On that particular charger (I have the same one), if you put a battery on charge, pull it out and put it straight back in, you can change the ‘beeps’. Two classical tunes and some random beeps. Which is nice. Edit: … you need to get the duff battery to about 15-20v for this trick to work. Good job spreading the word about this. You can do the same with any battery, even car batteries (lead acid type).
Good job scooby, i also have at least four of these makita batt packs that wont charge, some I haven’t even used in a tool before. I’m going to give this method a go. Thanks for taking the time to share your experience, i appreciate it.
Hi Adam, got my fingers crossed for you but I think it should work for you as your batteries are below the level to charge & doesn’t sound like damaged battery cells. thank you for the positive feedback & thank you for watching really appreciate it. Hope you are having a great day & it works for you
Scooby Rolla I managed to transfer a charge into the flat battery packs, even up to 18v but the charger still rejects them as I believe there is a built in circuit board that bricks them once they have been rejected by the charger a number of times. All the ones that are no good are 1.0 ah packs, both of the 3.0 ah packs I have haven’t given any problems. It has been an interesting experiment anyway, have a great day my friend.
Hi shane, Glad I could Help, 5 batteries that’s amazing mate 5 out of 5 you are definitely one of the luck ones. Thank you for watching really appreciate it. Hope you have a great day mate 👍🏼
I got mad at my 18 volt 6amp hour because it wouldn't take a charge. I slammed it twice on the concrete floor of my shop. Did not throw it down but wacked it really hard with it still in my hand, bottom of battery pack to the floor . Wack wack! Works just fine now. Been using it for at least 10 months now. Don't know what I did but it worked.
Thanks for posting this video theses batteries are so expensive I brought a brand new drill with battery and battery wouldn’t charge I think it must have been sitting in a warehouse for ages thanks
Your so right, I open up the battery and test every cell and see if there is a weak one and jump start the cell with another battery and I use a multimeter doing this, like the man said you can jump the battery by using another 18volt battery to give it more volts and then charge this and it works, PS buy a cheap multimeter and you can always check the battery for the volts. Good video and this video gives good explanation on how to do this thou 👍👏
Don't measure the batteries while the are connected together as you are only measuring the voltage drop across the wires which is created by the resistance in the wire.
No. He is measuring battery voltage. There is very little voltage drop across a single jumper wire since the wire has close to zero ohms resistance. He is measuring the voltage between wire 1 and wire 2 which are connected to positive and negative terminals. For example, if he performed a resistance test on each wire when disconnected from the terminals it would show less than 1 ohm or close to zero resistance (unless it was broken), therefore no voltage drop occurs over the wire.
@@robertmorin6495 If you wanna get really technical, read Kirchhoff's voltage law. He is measuring the voltage of both batteries, the bad battery reads slightly lower due to losses though the connections because they aren't good enough to allow the full flow of current between the batteries. When you jump-start a car with cables sometimes not enough power gets through due to the weak connections to turn over the engine fast enough to start even though the donor car is fully charged and running. If you removed the cells inside the bad battery it would read almost the same as the good battery from the outside terminals while it it is connected to the good one.
Thats a good hack if the charge controller or fuse hasn't gone. But you shouldn't charge the battery that fast as it could damage it. You should use a power supply where the current can not get too large to damage the battery or a power supply that has variable current control to limit the current. This is especially important when the battery is dead. If the cells total less than 2.5V per cell you probably don't want to bother reviving (if li-ion) You can sometimes find completely dead cells in the pack and you need to swap these dead ones out to fix the battery.
I know this is a old video but for those that have this issue, what happens is if the battery voltage gets too low there's a chip inside the battery (think of it as a fuse) that locks the battery and prevents it from being charged ever again. Battery voltage drops in batteries slowly when not in use and if you don't periodically charge these batteries and voltage drops too low the chip locks the battery. I would be curious if in this guys video if he used the battery that wouldn't charge and IF it charged as normal after doing what he did or IF the battery failed to charge again.
Hi Harry the battery was fine after that with no issues. But you are right there is a circuit board within the battery which monitor all the batteries in side. So if the batteries are leaking acid then it won’t let the charger recharge the batteries & the same again if the voltage is to low then it thinks there is problem with the batteries & again won’t charge it. That’s why if you are lucky & your batteries aren’t leaking acid & it’s low on voltage then usually this method will works. Hope this helps & thank you for sharing Harry
Those chips on batteries are for overcharge and over discharge protection. Makita has its own battery circuitry built on BMS on charger, which includes faulty battery detection. And Makita XT battery pack itself has circuitry to prevent over discharge upon which the battery would stop working until recharged. So Makita chargers would deem any battery with lower than rated voltage as faulty. But what happens is sometimes batteries would gradually discharge even when it isn't in use. Over heating the tool due over loading could lead to sudden over discharge, which could cause Makita to detect as defective.
When you do this (battery to battery), you should also use a resistor. A large voltage difference like you have here will generate high currents. Best way to revive a dead battery is to recharge it at low current until it reaches the minimum voltage.
You can calculate the resistor by dividing the voltage difference by the desired charging current. So for example if you have a battery charged at 19V and one discharged at 11V and you want a charging current of 0.5 Amp, then you have (19V - 11V) / 0.5 A = 8V/0.5A = 16 ohms Be sure to use a proper power rated resistor. In this case P = U * I = 4 W One resistor on the positive wire will suffice.
Go back 2 the JATC training center....the V diff is not that great, current not that high, good to be cautious, but kinda a waste of time soldering a resistor in line.....just my .02$ worth of ohms law.....solid calcs though....
hmm, I had 3 three (new) 2.0Ah batteries that were dead and wouldn't charge, they were ones I bought as spares and had been sitting in a 4 port Makita charger for maybe 9 months to a year. Went to use one, stone dead. Never realized that the alternating red/green blink was a bad battery error. Tried to charge on a rapid charger and it gave a beep code that sounded not good. Also have the Makita diagnostic thingy, which said the batteries were at
Hi, I’m so glad my video could help you & thank you for watching I really appreciate it. One bit of advice when storing your batteries make sure they are charged up & never leave them connected to the charger while they are in storage. As they discharge the battery to 0% and then they become very difficult to charge again. Hope this helps with future problems.
@@ScoobyRolla yea, those batteries were never stored in an unpowered charger, I know that's probably not a good idea. But I do think it might have had something to do with the 4 port charger, the 4 ports are not "Rapid" chargers, so they probably have less battery health logic in them. So the Makita Battery checker thing, tells you how many times the battery has been charged, how many times it has been over-discharged, and how many times it's overheated. It also tells you the overall voltage and the individual voltage and health of each cell. I've never tested a brand new battery straight out of the package before, but the recovered batteries look like I'd expect a new one to look like. Charged up: once, over discharged: never, over heated: never, all cells health at 100% and at max voltage. You'd think they would say at least over discharged: once, if they were not charged enough for the charger to charge it, right?
Once a cell goes below around 2.0 volts the electrodes become plated with lithium and begin to break down. That battery has 2 parallel sets of 5 cells in series which means damage starts at 10 volts, so don't expect the bad one to perform as good as it did before. Plus that heat is from too much current flowing between the batteries.
Sounds good. I'm gonna try it out. I hooked it up already. I'm starting with a fully charged 5.0ah good battery and I'm trying to revive a bricked 3.0ah. If it works, I have 3 bad batteries to try out. I'm just going to wait 10 minutes at a time and recharge the 5.0 every 10 minutes as well. Wish me luck.
You did well resetting it the thing you did wrong is keep putting it on and off you really needed another battery that had double the voltage in that battery to give it a good charge but glad it charged it enough to work 👍
Hi, James if they are charging but not holding charge for long time that means that battery cells leaking inside the battery casing or cells within battery are dying. Hope this helps
good video, help save the waste. most chargers won't start if the voltage is too low, just make sure you keep them in sight when using jumpers as a really failed battery may short and can cause a fire.
I find it interesting that your charger sounds like it has a fan running but mine is silent. Yours also played a little tune at one point. I've never seen one that does that.
Hi, yes it has a built in fan to cool the battery down if it hot from using it while you are charging it & yes if you take battery in & out of the charger it will different music. I’ve done a video on this. Hope this helps & thank you for watching I really appreciate it.
i found a way that is easier for me. i run wires from a 20v nimh charger plugged into a timer set for 9 hours. i experimented bit by bit to work out the best way making sure nothing overheated. the nimh charger hasnt got the guts to overcharge and cook the 4ah battery. ive been using this system for 5 years. i always do it in a steel shed with a concrete floor so there is no fire risk. the makita chargers are happy with all my other batteries.
Yeah old makita batteries are bad, but so far my are still holding up, but the newer makita are a huge improvement. And the three year warranty got two of my batteries replaced, no questions asked( I dropped them from a fully extended scissor lift 😅)
if you leave it on the charger, there is a fan which blows cool air around the battery if you leave it to charge it will cool it down. a lot of these batteries over heat and that fucks them up. inside the charger it has some fancy electronics in side wich monitors each cell, when they go faulty its possibly one of the cells that not up to scratch, it stops the charging due to a voltage/current imballance.
I have the opposite issue with my Makita battery. It's an 18 volt battery but the charger put 20 volts in it and now it won't run the tools. I'm trying to discharge it now to see if it will eventually work.
What if I use a battery (used to jump start car) and connect it to copper that makes contact with positive and negative, will it technically be doing the same thing?
Should work. I shoved a couple of pennies in the tool connection slots in the battery, and hooked it to an automotive battery charger's clamps (12V). Doesn't have the safeties of a real lithium ion charger though, so don't leave home with it plugged in, and set it in relatively fire safe area. And don't mix up the polarity!
Awesome! Thanks for sharing mate, just what I needed to know and will save me a few bob too! No I know this bit is going to sound bonkers but I've been meaning to learn how to use a multi meter for ages but never got round to it. Please could you share the make and model of the one that you used? Thanks in advance. All the best, Steve.
I don't have the money to go out and buy two batteries. It'll run for about 2 minutes if that and shut right off. I got a six-speed blower but they say Makita will work in that you're going to interchangeable but I haven't seen one yet. If any questions give me a call. I love Makita😮
The batteries are getting warm as you are putting a higher voltage through with more amps. You need a lower voltage or lower current to charge the battery to reduce heat. 9v with 20v is a lot, nit surprised it is getting warm. Your mistake is a 10 second charge from a well charged battery. Connect until good battery drops to 15v, fully charge the good battery, then connect them and drain until 15v or both are matched. Wait until they cool, then monitor to see if the discharged battery (bad) holds its charge. Bad batteries drop charge quickly.
Hey scooby great video. I've got a 1.3ah battery and have tried to bring it back to life as shown on your video. Voltage came up to 17.6V however it still can't charge. Is there anything else I can do or am I missing something? Side note : the battery hasn't been used nor charged in a few years
Hi you may need a battery that’s like a dewalt battery a 32v battery to give it a really good charge so the charger recognises it a 18v to 18v would take a while to give the power to it but if you double it using another battery with higher voltage the chances of it working are around 80% as it will give it more charge quicker hope this helps 👍
Use a hobby charger or a bench PSU with current limiting. If you must charge battery to battery Fully charge the good battery in the charger.Charge the bad one with the good one for a few minutes . Repeat. Pause when either gets warm.
This does work as I did it last week however I have to go through the same rigmarole every time I want to charge it so not much help in the scheme of things.
I tried this today the same as you. 14.4 v. I charged it slowly and got back up to 14.4 . Put it on the charger , did not work, tried it in the drill, did not work. My best guess is ,,,,,, The chip board , somehow the low voltage is recorded on the chipboard and it will register it dead even if you measure a good voltage. It's how they keep selling batteries . In another video I saw they changed the chipboard to get over the problem which I am now ordering from China at 4.50€.
Hi, If the circuit board is blown it will stops the battery charging up but if you’ve charged the battery & it’s not working in the drill it could be damaged batteries cells. Tell us know how you get on & good luck.
i think if you have a power supply, you can charging it with proper method (constant current and voltage).. rather than charging the battery with another battery (because the current from the battery itself is too high for the cells).. charging with dc power supply far more easier and you can more easily to monitoring and adjusting with proper voltage and thus the current charging..
dont put the good battery on the bad one for a long time.. put in on for a minute and then recharge the good battery. That way you arent overheating the good battery or lowering its voltage too much. Also be very careful you dont hook positive to negative, as that would create a direct short and possibly a fire or explosion. Lithium ion batteries are nothing to trifle with!
Got my Makita battery up to 19v but it still makes the same noise on the charger and even though it's fully charged when I put it on a drill it only makes the light come on. Any ideas? 🤔
The worse thing is about the makita battery are that they have a circuit board inside the battery (1). Some times if the battery goes below a certain charge the board refuses to charge the battery. (2). & some times the battery cells leak acid on to them & damaged them so they refuse to charge up. I’m really sorry but it sounds like the board in the battery is damaged. I’m sorry I could help. Thanks for watching I really appreciate it.
It might be worth opening it up to see what’s happened to it or you could sell it on eBay as some people buy them & open them up & repair & sell them on. Hope this helps, might be better off selling it & putting some money on top & buying another.
Scooby Rolla Thanks for the reply. I see on other sites they say that if you put the battery on the charger and it fails to except it three times a chip or fuse on the circuit board blows or blocks it from charging again even if the batteries inside are ok. I have no fun to change the circuit board so will sell it on as the individual batteries inside must be ok. I only paid 10€ including postage so haven't lost anything.
This is happening to two of my batteries with all good cells. Even at 18.5v they refuse to be accepted by the charger. My 3 amp battery has no problem even when I drain dead.
Hi Jerry try another battery on the charger to make sure it is working if it is then it could be that cells in battery are damaged & leaking on the battery what won’t charge. Hope this helps sorry about the delay in responding
Hi, you Can use any old cables from a old appliance wire. Just cut a length of it, then strip the collar off, then there will be three wire which you can use 2 of them. Hope this helps.
Use 14 gauge automotive wire, color coded black/red with the right size alligator clips. Less mistakes that way and the wire is more flexible, too. Black is always negative, or ground.
Hi, you Can use any old cables from a old appliance wire. Just cut a length of it, then strip the collar off, then there will be three wire which you can use 2 of them. Hope this helps. Sorry about the delay in responding
What gauge/diameter wire did you use? When I insert the lugs into the positive and negative terminals to both batteries, mine sparked a loud crack and bright green flame and burnt the entire length of cables.
if you move faster the voltage on the bad battery will not have time to drop....Alternatively you can charge the bad battery by connecting the good battery in parallel and to the charger at the same time. Could have charged the bad battery in the time this video ran....
Just curious as to how you established the battery was faulty in the first place? What lights were activated on the charger to give you this information? Thanks.
Hi, at the beginning of the video I put the faulty battery on the charger and it starts beeping and flashing red and green and on the charger it shows a diagram and faults and shows red and green lights flashing and beeping showing a broken battery sign at the end of it. check the beginning of the video. Hope this helps
Sadly, it won't always work this way. I have gotten 3 dead Makita batteries from a friend - after I told him I fixed one by replacing the dead cells - none of them will charge on the Makita fast charger DC18RC. 1 has a problem with it's temp sensor. The other 2 have a fault in their control board. As of writing this I have 2 Makita batteries connected + to + and - to -, the same as you :P
Hi Chriss, if it’s back up to 18v and it won’t charge then it might be one or the other, the cells are leaking acid within the case or circuit board within case is blown which won’t allow the battery charger to charge. Sounds like the circuit board within is blown. I know some people have got a old laptop charger to use to charge the battery as it provides 18v to 20v but haven’t needed to it myself. But if your cells are leaking you can check it by leaving them for a bit and then checking the voltage if it losses all the charge then the are damaged within. Hope this helps
Another thing if you do use a laptop power lead Be very careful please. Make sure you connect wires first then plug it in. Playing on head. Hope this helps
@@donaldsaunders4736 the chip tells charger battery is bad. I ended up replacing a dead cell in the pack its good now but won't work on charger because of the chip.
My Makita impact drill battery would not charge, after being left flat for six months, and I tried fitting and removing it rapidly from the charger repeatedly in quick succession to 'reset the chip' but this did not work. So, after watching your video Scooby Rolla I did not have a second battery to use as you have done, so I used an old 16V, 0.5amp charger which I had lying around home from some unknown appliance or radio long gone from my home, and I stripped the two wires coming out of the charger and hooked them to the dead Makita battery for about an hour and then tried the battery in the charger. Bingo, the battery charged right up to full, and now I don't have to do anything further to it. Your video made me try this idea, and it worked. Thanks very much.
So I glad I could help & thank you for sharing your idea too
Scooby Doo!. 20 minutes all wired up worked a treat. Saved on a new battery. Kudos. Thanks and God bess
You are welcome, I’m so glad it worked for you & thank you for watching really appreciate it. Hope you having great weekend
superb just rebooted my battery by connecting an external power supply at 10V 2A to + and -. Took about 1 min to get enough juice in it to then allow the charger to see it. This is so simple thanks so much. Significantly easier than rescuing a drone battery !
Awesome I jumpered my Ryobi 3ah to it for about five minutes and bam 9.6 to 18 something volts. The reason for my voltage drop was years between charges while in storage. Charges now, thank you so much!
Hi Kevin, So glad it worked for you & thanks for watching really appreciate it.
Worked for me. Revived 6amp battery with the 5 amp. Cheers mate. This video saved me 90 quid.
So glad I could help & thank you for the feedback. I think we are one of the lucky ones who didn’t have battery leaking acid or circuit board damage in the battery. Thank you for watching I really appreciate it. Hope you’re having a great day
There's a safety chip inside de battery that breaks when the power goes bellow the limit, you have to dismantle the battery and bypass a safety chip by soldering a wire to fool the charger
There's a video in spanish in RUclips that will teach you how to do it
You just type in the browser
"Como reparar una batería makita"
You might need someone to translate
But it's pretty simple you should be able to know what he is doing and how to do it even if you dont speaks spanish
I used a solar panel and 14/2 gauge Romex Home wireing harness +/- to re-charge a previously bricked Makita 18 Volt Battery. Then the Makita Charger's micro processor agreed to charge the previously Bricked18 Volt Makita Battery to fully recharge thar Bricked 18 Volt Makita Battery. Then I used the previously Bricked 18 Volt Battery and was able to recharge the Makita 18 Volt Battery again :). Thank you !
This video worked perfectly and was the most non invasive for me. Thanks for taking the time.
Definetely going this a try, have 3 "dead" batteries hoping to revive..
Loved your comments in the video, it was a pleasure watching.. Even if it doesn't work for me I had a good time watching ;) Cheers
Any updates?
@@P105Mews neh sadly not working on mine..
@@Damaniac0064 bummer. I'll give my one a try and see how I go. It's a 1.3mah pack
Well done for persistence..I was hooked
Thank you Craig appreciate it
Worked like a charm after 10 minutes. Thanks for making the video.
Thanks curtis so glad I could help & really happy it worked for you. Thank you so much for the positive feedback & thank you for watching. Hope you are having a great day
What did you use to bridge both batteries? I tried using a battery used to jump start car and that didn't work (used copper to connect positive and negative to respective terminals)
Thanks, it worked for me! The faulty battery is working again!
On that particular charger (I have the same one), if you put a battery on charge, pull it out and put it straight back in, you can change the ‘beeps’. Two classical tunes and some random beeps. Which is nice.
Edit: … you need to get the duff battery to about 15-20v for this trick to work. Good job spreading the word about this. You can do the same with any battery, even car batteries (lead acid type).
Works perfect. Just connected the dead battery for 3 min and started to change again
i'm so glad it work for you andriy you are one of the lucky ones. thank you watching really appreciate it.
@@ScoobyRolla
Thank you again
Good job scooby, i also have at least four of these makita batt packs that wont charge, some I haven’t even used in a tool before. I’m going to give this method a go. Thanks for taking the time to share your experience, i appreciate it.
Hi Adam, got my fingers crossed for you but I think it should work for you as your batteries are below the level to charge & doesn’t sound like damaged battery cells. thank you for the positive feedback & thank you for watching really appreciate it. Hope you are having a great day & it works for you
Scooby Rolla I managed to transfer a charge into the flat battery packs, even up to 18v but the charger still rejects them as I believe there is a built in circuit board that bricks them once they have been rejected by the charger a number of times. All the ones that are no good are 1.0 ah packs, both of the 3.0 ah packs I have haven’t given any problems. It has been an interesting experiment anyway, have a great day my friend.
Good advice never gets old. I followed your video and revived two batteries from the grave. Thanks for making the video and for sharing.
You have just saved me from buying 5 more batteries Thank you
Hi shane, Glad I could Help, 5 batteries that’s amazing mate 5 out of 5 you are definitely one of the luck ones. Thank you for watching really appreciate it. Hope you have a great day mate 👍🏼
I got mad at my 18 volt 6amp hour because it wouldn't take a charge. I slammed it twice on the concrete floor of my shop. Did not throw it down but wacked it really hard with it still in my hand, bottom of battery pack to the floor . Wack wack! Works just fine now. Been using it for at least 10 months now. Don't know what I did but it worked.
They do say if something doesn’t work give a wack a couple of times it might do the job 😂
Thanks for posting this video theses batteries are so expensive I brought a brand new drill with battery and battery wouldn’t charge I think it must have been sitting in a warehouse for ages thanks
Many thanks bro
You helped me!
Thanks
Glad I could help & thank you for watching
Your so right, I open up the battery and test every cell and see if there is a weak one and jump start the cell with another battery and I use a multimeter doing this, like the man said you can jump the battery by using another 18volt battery to give it more volts and then charge this and it works, PS buy a cheap multimeter and you can always check the battery for the volts. Good video and this video gives good explanation on how to do this thou 👍👏
Thanks for the video I’m up and running as a result of your time and efforts thanks so much
Chris
Instablaster
Don't measure the batteries while the are connected together as you are only measuring the voltage drop across the wires which is created by the resistance in the wire.
Thanks for that 👍🏼
:)
No. He is measuring battery voltage.
There is very little voltage drop across a single jumper wire since the wire has close to zero ohms resistance. He is measuring the voltage between wire 1 and wire 2 which are connected to positive and negative terminals. For example, if he performed a resistance test on each wire when disconnected from the terminals it would show less than 1 ohm or close to zero resistance (unless it was broken), therefore no voltage drop occurs over the wire.
@@robertmorin6495 If you wanna get really technical, read Kirchhoff's voltage law. He is measuring the voltage of both batteries, the bad battery reads slightly lower due to losses though the connections because they aren't good enough to allow the full flow of current between the batteries. When you jump-start a car with cables sometimes not enough power gets through due to the weak connections to turn over the engine fast enough to start even though the donor car is fully charged and running. If you removed the cells inside the bad battery it would read almost the same as the good battery from the outside terminals while it it is connected to the good one.
Mine worked too... the dead one was at 13.5v and I've only left it for 5' until it got to 14.5v and the charger took it from there! Cheers
I’m so glad it for for you, one if the lucky ones. Thank you for watching I really appreciate it.
Thats a good hack if the charge controller or fuse hasn't gone. But you shouldn't charge the battery that fast as it could damage it. You should use a power supply where the current can not get too large to damage the battery or a power supply that has variable current control to limit the current. This is especially important when the battery is dead. If the cells total less than 2.5V per cell you probably don't want to bother reviving (if li-ion) You can sometimes find completely dead cells in the pack and you need to swap these dead ones out to fix the battery.
Thanks for sharing izzzzz
Great video, thanks. Thought I'd lost myself 2 of the 4 5amp batteries I had 👌👌👌👌💯💯💯💯
Where can I find that wire you used to connect the batteries up?
You can make it yourself with any 12-15 gauge wire and male electrical connector ends. Very easy and surely found at harbor freight or walmart
I’m definitely trying this method tomorrow. Hope it works for me
is that battery still usable?
I'm doing this trick as we speak...thanks dude😅
Thank you brother 😊😊😊i saved mine
How many year/month did the recover faulty battery work well again?
Yes, fixed mine with this method. Thank you.
One of the lucky ones. Glad I could help & thank you for watching I really appreciate it
I know this is a old video but for those that have this issue, what happens is if the battery voltage gets too low there's a chip inside the battery (think of it as a fuse) that locks the battery and prevents it from being charged ever again. Battery voltage drops in batteries slowly when not in use and if you don't periodically charge these batteries and voltage drops too low the chip locks the battery.
I would be curious if in this guys video if he used the battery that wouldn't charge and IF it charged as normal after doing what he did or IF the battery failed to charge again.
Hi Harry the battery was fine after that with no issues. But you are right there is a circuit board within the battery which monitor all the batteries in side. So if the batteries are leaking acid then it won’t let the charger recharge the batteries & the same again if the voltage is to low then it thinks there is problem with the batteries & again won’t charge it. That’s why if you are lucky & your batteries aren’t leaking acid & it’s low on voltage then usually this method will works. Hope this helps & thank you for sharing Harry
Does that mean that it's not possible anymore to charge the dead battery or is there a solution?
Those chips on batteries are for overcharge and over discharge protection. Makita has its own battery circuitry built on BMS on charger, which includes faulty battery detection. And Makita XT battery pack itself has circuitry to prevent over discharge upon which the battery would stop working until recharged. So Makita chargers would deem any battery with lower than rated voltage as faulty. But what happens is sometimes batteries would gradually discharge even when it isn't in use. Over heating the tool due over loading could lead to sudden over discharge, which could cause Makita to detect as defective.
When you do this always start with a fully charged battery. If you don't you risk damaging your good battery by dropping the voltage too low.
When you do this (battery to battery), you should also use a resistor. A large voltage difference like you have here will generate high currents.
Best way to revive a dead battery is to recharge it at low current until it reaches the minimum voltage.
Resistor on both wires? How many ohms should we use?
You can calculate the resistor by dividing the voltage difference by the desired charging current. So for example if you have a battery charged at 19V and one discharged at 11V and you want a charging current of 0.5 Amp, then you have (19V - 11V) / 0.5 A = 8V/0.5A = 16 ohms
Be sure to use a proper power rated resistor. In this case P = U * I = 4 W
One resistor on the positive wire will suffice.
The wire being used to connect the two batteries provides a resistance
@@lexluger9 I'll let you find out the resistance and the resulting current ;)
Go back 2 the JATC training center....the V diff is not that great, current not that high, good to be cautious, but kinda a waste of time soldering a resistor in line.....just my .02$ worth of ohms law.....solid calcs though....
hmm, I had 3 three (new) 2.0Ah batteries that were dead and wouldn't charge, they were ones I bought as spares and had been sitting in a 4 port Makita charger for maybe 9 months to a year. Went to use one, stone dead. Never realized that the alternating red/green blink was a bad battery error. Tried to charge on a rapid charger and it gave a beep code that sounded not good. Also have the Makita diagnostic thingy, which said the batteries were at
Hi, I’m so glad my video could help you & thank you for watching I really appreciate it. One bit of advice when storing your batteries make sure they are charged up & never leave them connected to the charger while they are in storage. As they discharge the battery to 0% and then they become very difficult to charge again. Hope this helps with future problems.
@@ScoobyRolla yea, those batteries were never stored in an unpowered charger, I know that's probably not a good idea. But I do think it might have had something to do with the 4 port charger, the 4 ports are not "Rapid" chargers, so they probably have less battery health logic in them.
So the Makita Battery checker thing, tells you how many times the battery has been charged, how many times it has been over-discharged, and how many times it's overheated. It also tells you the overall voltage and the individual voltage and health of each cell.
I've never tested a brand new battery straight out of the package before, but the recovered batteries look like I'd expect a new one to look like. Charged up: once, over discharged: never, over heated: never, all cells health at 100% and at max voltage. You'd think they would say at least over discharged: once, if they were not charged enough for the charger to charge it, right?
Hi!! What voltage are cables been used?
Quality, and very down to earth video spot on 👍
Thanks Pete appreciate it
Once a cell goes below around 2.0 volts the electrodes become plated with lithium and begin to break down. That battery has 2 parallel sets of 5 cells in series which means damage starts at 10 volts, so don't expect the bad one to perform as good as it did before. Plus that heat is from too much current flowing between the batteries.
Thank you for sharing that good to know.
Great one, i will try my Makita batteries with your video description and send test result to you. Thanks.
Yay! I'm trying this right now.
Worked for me 2! Thank you fine sir
You are welcome Brian glad I could helps, you are one many lucky ones. Thank you for watching brian really appreciate it 👍🏼
Sounds good. I'm gonna try it out. I hooked it up already. I'm starting with a fully charged 5.0ah good battery and I'm trying to revive a bricked 3.0ah. If it works, I have 3 bad batteries to try out. I'm just going to wait 10 minutes at a time and recharge the 5.0 every 10 minutes as well. Wish me luck.
Good luck patrick
Do tell?
Did work?
So useful, Thank you!
Thank you so glad I could help & thank you for watching really appreciate it, hope you’re having a great day stay safe
You did well resetting it the thing you did wrong is keep putting it on and off you really needed another battery that had double the voltage in that battery to give it a good charge but glad it charged it enough to work 👍
Worked for me thanks
I will try it out and hope it will work on mine as well. Thx for your vid. 👍👍😉
Didn't work. Hmmm
Sorry just seeing this video now. I have 2 batteries that take charge but it doesn't hold for long. Can they be revived? Thanks great upload.
Hi, James if they are charging but not holding charge for long time that means that battery cells leaking inside the battery casing or cells within battery are dying. Hope this helps
Best to sell them for cheap on eBay & replace them with new one because eventually they will not hold charge at all. Hope this helps
@@ScoobyRolla yeah thanks for getting back to me I'll buy the adapter and a couple of lithium's I think haha. 👍🏻
The Decent Battery... A good band name?
Can i use a good Ni Cd battery to revive a dead Lithium one? They both have the same voltage
Informative Thanks for uploading. Cheers from smoky Australia.
Thank you smoky & thank you for watching really appreciate it 👍🏼
Thank you - I'm going to try this on mine!
Good luck 👍🏼& thank you for watching
Good job!!
good video, help save the waste. most chargers won't start if the voltage is too low, just make sure you keep them in sight when using jumpers as a really failed battery may short and can cause a fire.
Good point Jerry, thank you for sharing & thank you for watching to hope you are having a great day
I find it interesting that your charger sounds like it has a fan running but mine is silent. Yours also played a little tune at one point. I've never seen one that does that.
Yours will play a tune too.. what you have to do is slide the battery in and out again twice quickly. It will then play a tune when full charged 👌
Hi, yes it has a built in fan to cool the battery down if it hot from using it while you are charging it & yes if you take battery in & out of the charger it will different music. I’ve done a video on this. Hope this helps & thank you for watching I really appreciate it.
Thank you for sharing & thank you for watching
Makita fast chargers have fans.
That’s right thank you for sharing
You have to leave the batteries longer Evan though you hear the buzzing it will adjust after 15 minutes.
Great video man. You just saved me $80 bucks. Much appreciated.
Glad to help mark really happy it worked for you. One of the lucky ones 👍🏼. Hope you have a great day
i found a way that is easier for me. i run wires from a 20v nimh charger plugged into a timer set for 9 hours. i experimented bit by bit to work out the best way making sure nothing overheated. the nimh charger hasnt got the guts to overcharge and cook the 4ah battery. ive been using this system for 5 years. i always do it in a steel shed with a concrete floor so there is no fire risk. the makita chargers are happy with all my other batteries.
Thank you for sharing & I will give it a go next time. Thank you for watching I really appreciate it
Makita batteries are the reason I own all dewalt stuff now.
Thanks for sharing Justin & thanks for watching
Yeah old makita batteries are bad, but so far my are still holding up, but the newer makita are a huge improvement. And the three year warranty got two of my batteries replaced, no questions asked( I dropped them from a fully extended scissor lift 😅)
Dewalt tools are the reason I put up with makita battery’s
@@Marky948 I had so many makita lithium batteries go completely defective and wouldn’t charge. Never a problem with dewalt
Makitas are just dewalt in blue skin, look it up
if you leave it on the charger, there is a fan which blows cool air around the battery if you leave it to charge it will cool it down. a lot of these batteries over heat and that fucks them up. inside the charger it has some fancy electronics in side wich monitors each cell, when they go faulty its possibly one of the cells that not up to scratch, it stops the charging due to a voltage/current imballance.
Thanks for sharing Brian 👍🏼
I just connected mine to a car battery charger for 10 mins worked a treat.
I have the opposite issue with my Makita battery. It's an 18 volt battery but the charger put 20 volts in it and now it won't run the tools. I'm trying to discharge it now to see if it will eventually work.
A full 18 volt battery is up to 21v. 5 batteries x 3.6 nominal = 18v, 5 batteries at 4.2v peak = 21v. So 20v is ok.
What if I use a battery (used to jump start car) and connect it to copper that makes contact with positive and negative, will it technically be doing the same thing?
Should work. I shoved a couple of pennies in the tool connection slots in the battery, and hooked it to an automotive battery charger's clamps (12V). Doesn't have the safeties of a real lithium ion charger though, so don't leave home with it plugged in, and set it in relatively fire safe area. And don't mix up the polarity!
Buy yourself a bench power supply,they are not expensive. A 30v-10A will help you out on many projects.
Hi, thank you, Appreciate the advice
Awesome!
Thanks for sharing mate, just what I needed to know and will save me a few bob too!
No I know this bit is going to sound bonkers but I've been meaning to learn how to use a multi meter for ages but never got round to it. Please could you share the make and model of the one that you used?
Thanks in advance.
All the best,
Steve.
big clive did a good video about how to use a multimeter about a month ago.
if you want to know about multi meters you have to check out this old tony
I don't have the money to go out and buy two batteries. It'll run for about 2 minutes if that and shut right off. I got a six-speed blower but they say Makita will work in that you're going to interchangeable but I haven't seen one yet. If any questions give me a call. I love Makita😮
The batteries are getting warm as you are putting a higher voltage through with more amps. You need a lower voltage or lower current to charge the battery to reduce heat. 9v with 20v is a lot, nit surprised it is getting warm. Your mistake is a 10 second charge from a well charged battery.
Connect until good battery drops to 15v, fully charge the good battery, then connect them and drain until 15v or both are matched.
Wait until they cool, then monitor to see if the discharged battery (bad) holds its charge. Bad batteries drop charge quickly.
A bit long winded, but with fast forward an informative video. Useful.
thank you Paul appreciate it. I know it was a bit long winded but wanted to show everything. Thank you for watching hope you have a great day
Hey scooby great video. I've got a 1.3ah battery and have tried to bring it back to life as shown on your video. Voltage came up to 17.6V however it still can't charge. Is there anything else I can do or am I missing something?
Side note : the battery hasn't been used nor charged in a few years
Hi you may need a battery that’s like a dewalt battery a 32v battery to give it a really good charge so the charger recognises it a 18v to 18v would take a while to give the power to it but if you double it using another battery with higher voltage the chances of it working are around 80% as it will give it more charge quicker hope this helps 👍
Nice one mate
Use a hobby charger or a bench PSU with current limiting. If you must charge battery to battery Fully charge the good battery in the charger.Charge the bad one with the good one for a few minutes . Repeat. Pause when either gets warm.
Hi frank, I agree
Hindsight is a wonderful thing.
Neither which are cheap. If you have them - great. If not - might as well purchase new batteries.
Defo trying it , thanks 👍
This does work as I did it last week however I have to go through the same rigmarole every time I want to charge it so not much help in the scheme of things.
I tried this today the same as you. 14.4 v. I charged it slowly and got back up to 14.4 . Put it on the charger , did not work, tried it in the drill, did not work. My best guess is ,,,,,, The chip board , somehow the low voltage is recorded on the chipboard and it will register it dead even if you measure a good voltage. It's how they keep selling batteries . In another video I saw they changed the chipboard to get over the problem which I am now ordering from China at 4.50€.
Hi, If the circuit board is blown it will stops the battery charging up but if you’ve charged the battery & it’s not working in the drill it could be damaged batteries cells. Tell us know how you get on & good luck.
@@ScoobyRolla yep, 4 cells where down, either 0 reading or less than 1 volt .
Do you have a link for the chipboard please x
i think if you have a power supply, you can charging it with proper method (constant current and voltage)..
rather than charging the battery with another battery (because the current from the battery itself is too high for the cells)..
charging with dc power supply far more easier and you can more easily to monitoring and adjusting with proper voltage and thus the current charging..
Where is the link for that clip wire thing you using?
dont put the good battery on the bad one for a long time.. put in on for a minute and then recharge the good battery. That way you arent overheating the good battery or lowering its voltage too much. Also be very careful you dont hook positive to negative, as that would create a direct short and possibly a fire or explosion. Lithium ion batteries are nothing to trifle with!
Thank you sharing
@@ScoobyRolla no problem. Just want people to be safe
top work sir
Got my Makita battery up to 19v but it still makes the same noise on the charger and even though it's fully charged when I put it on a drill it only makes the light come on. Any ideas? 🤔
The worse thing is about the makita battery are that they have a circuit board inside the battery (1). Some times if the battery goes below a certain charge the board refuses to charge the battery. (2). & some times the battery cells leak acid on to them & damaged them so they refuse to charge up. I’m really sorry but it sounds like the board in the battery is damaged. I’m sorry I could help. Thanks for watching I really appreciate it.
It might be worth opening it up to see what’s happened to it or you could sell it on eBay as some people buy them & open them up & repair
& sell them on. Hope this helps, might be better off selling it & putting some money on top & buying another.
Scooby Rolla Thanks for the reply. I see on other sites they say that if you put the battery on the charger and it fails to except it three times a chip or fuse on the circuit board blows or blocks it from charging again even if the batteries inside are ok. I have no fun to change the circuit board so will sell it on as the individual batteries inside must be ok. I only paid 10€ including postage so haven't lost anything.
This is happening to two of my batteries with all good cells. Even at 18.5v they refuse to be accepted by the charger.
My 3 amp battery has no problem even when I drain dead.
i have a dewalt gharger and batt. plug it in and nothing my charger has a light on to let you no but thats not working either?
Hi Jerry try another battery on the charger to make sure it is working if it is then it could be that cells in battery are damaged & leaking on the battery what won’t charge. Hope this helps sorry about the delay in responding
Hi how to order the makita battery and charger of 14.4 volt
Thank you
Where do you get those type of cables?? I have two batteries doing the same thing, and I definitely will try to do this!!
Hi, you Can use any old cables from a old appliance wire. Just cut a length of it, then strip the collar off, then there will be three wire which you can use 2 of them. Hope this helps.
Use 14 gauge automotive wire, color coded black/red with the right size alligator clips. Less mistakes that way and the wire is more flexible, too. Black is always negative, or ground.
I jump charged mine and it went up to 16.8v untill one section was really hot so i actually had 2 bad cells. Mine is a Bl1830
Just be careful if they get to hot they can blow up.
it needs 12.5 v to charge. 2.5vx5 cells.
No
@Scooby Rolla. Hi, my battery only charges for about 1 minute then it stops charging... Have you heard that before? Great video btw....
How long in totale did you leave it on charge ?
Danoh Danoh I’m not sure you know. Enough so that it could charge up by itself.
Could you tell me where you got rhe wires I need to copy your solution
Hi, you Can use any old cables from a old appliance wire. Just cut a length of it, then strip the collar off, then there will be three wire which you can use 2 of them. Hope this helps. Sorry about the delay in responding
What gauge/diameter wire did you use? When I insert the lugs into the positive and negative terminals to both batteries, mine sparked a loud crack and bright green flame and burnt the entire length of cables.
when you drained a good battery you should charge it up and then give the bad one a charge from the fully charged good one
Thanks for sharing
Should use a current limiting device like a 12v 25watt light bulb before one or both batteries burn
if you move faster the voltage on the bad battery will not have time to drop....Alternatively you can charge the bad battery by connecting the good battery in parallel and to the charger at the same time. Could have charged the bad battery in the time this video ran....
Good point Daniel. Thanks for sharing
Just curious as to how you established the battery was faulty in the first place? What lights were activated on the charger to give you this information? Thanks.
Hi, at the beginning of the video I put the faulty battery on the charger and it starts beeping and flashing red and green and on the charger it shows a diagram and faults and shows red and green lights flashing and beeping showing a broken battery sign at the end of it. check the beginning of the video. Hope this helps
Literally watch the video
What a thicko.... did you watch the full video...it wont charge 🤣
Sadly, it won't always work this way. I have gotten 3 dead Makita batteries from a friend - after I told him I fixed one by replacing the dead cells - none of them will charge on the Makita fast charger DC18RC. 1 has a problem with it's temp sensor. The other 2 have a fault in their control board. As of writing this I have 2 Makita batteries connected + to + and - to -, the same as you :P
Helped me and many thanks, People should post their own video if they think they can do so much better. So many whingers in this world.....
I agree mark. So glad it for worked for you Mark. Really appreciate you watching to 👍🏼
how long did it last ?
Hi, Still working
your method got my battery to 18volts but it still wont charge
Hi Chriss, if it’s back up to 18v and it won’t charge then it might be one or the other, the cells are leaking acid within the case or circuit board within case is blown which won’t allow the battery charger to charge. Sounds like the circuit board within is blown. I know some people have got a old laptop charger to use to charge the battery as it provides 18v to 20v but haven’t needed to it myself. But if your cells are leaking you can check it by leaving them for a bit and then checking the voltage if it losses all the charge then the are damaged within. Hope this helps
Another thing if you do use a laptop power lead Be very careful please. Make sure you connect wires first then plug it in. Playing on head. Hope this helps
Unplug your charger and plug it back in 5 times fast👍
@@donaldsaunders4736 the chip tells charger battery is bad. I ended up replacing a dead cell in the pack its good now but won't work on charger because of the chip.
Thank you :-)
Does it still work
Any update on how the faulty battery is now?.