Makita 18V Battery Has Big Problem! 

looks like you should change title to after-market "makita" batteries have huge problem..

Discovered this issue a few years ago, specifically on the 14.4 battery packs, (because these were the ones we were using). On the early batteries the battery management board is permanently powered from the first pair of cells, resulting in the first pair of cells always being slightly more discharged than the rest of the cells. This issue builds up, especially if the batteries are stored for a long period. When the battery is used with the drill the first pair of cells eventually get slightly over discharged, which degrades them faster than the rest of the pack and reduces their effective capacity. I believe there is some natural cell balancing when the battery is repeatedly discharged and charged, however if the battery is stored this does not appear to be enough and the first pair of cells dies first. It feels like a design fault/money saving exercise/intentional battery lifetime limiting feature, which makita have decided is acceptable because it doesn't normally kill the batteries before the 1000 charges in continuous professional use of the 4-5 years of DIY use. As a side note, The battery management board on the early batteries communicates with the charger and appears to count charges and disable the battery if the number if charges exceeds a number, I have guessed at 1000 charges, remember putting a full battery onto the charger to see if it is full counts as a charge... I expect this is a 'safety feature' which the marketing department wet themselves over.

It is good to mention that original Makita 18V battery does not include low voltage and over voltage protection. A MOSFET is inside every Makita tool. Important if you use the battery for purposes other than Makita. That's why I added a whole new BMS to the battery that has over and under voltage protection MOSFET included.

The clone battery does not have any balancing leads. the leads which are connected are a measuring wire to check the first cell. This is used to do the fuel gauge and the internal electronics, which are much easier to drive from 3.5V-4.2V and not the full pack voltage. The original board is deactivating the charging, not only with unbalanced cells, but also with low-voltage cells. Which could be charged but are very likely to fail soon and are not capable any more to deliver the currents needed. Therefore makita is deactivating the battery. I dont really like this from a sustainability point of view, but as a manufacturer which have to garanty the current and power delivery for these battery it makes sense.

Really well done, dude! Fantastic work! 😃 Stay safe there with your family! 🖖😊 And happy holidays!

Funny thing, I came up with exactly same situation about 5 years ago. I got a bucket full of discarded Makita batteries. Some were ok, just low voltage. Some had 1 phase dead, others fine. Makita's charger would not charge them since battery circuits have low voltage memory. I did exactly same solution. I didn't have 3d printer so I made the adapter out of plywood. Also I didn't use epoxy for connector attachment (I think I wil do it now). Still use it today to charge them with hobby charger. Great video!

Great video mate. Quick question, some of my old makita batteries need changing a lot quicker, any fix for that one ? Many thanks

Very clear, well done.

Cells will become unbalanced with age, it's a normal part of the degradation process. When charging it with a RC charger like this, you're top balancing them and you might find at some point that you need to do this more and more often and maybe even with every charge, because they will not stay in balance. This might cause problems with the low voltage protection, because the individual cells aren't monitored during discharge and you rely on the low voltage protection that only checks the pack voltage. With the same modifications shown in the video, you could also bottom balance the cells. You discharge all cells individually to, for example, 3.0V. For optimal efficiency, you match this voltage times five with the low voltage protection of the power tool or the battery protection circuit. Then, you charge the pack, but without balancing the cells (much like the original charger would do, or the RC charger does without the balance wires connected or the balance charge option selected). While charging, you monitor the individual cell voltages through your newly fitted balance connector. Towards the end of the charge, the cell voltages will drift and become unbalanced at the top of their charge cycle. You wait until the first cell reaches your desired end of charge voltage. Could be 4.20V, but you could also consider a slightly lower voltage, like 4.1V or 4.0V, which will increase the longevity of the cells. At that point, all the other cells will have a different voltage. You then take note of the pack voltage. This is your new end of charge voltage for the entire pack. You can then discharge the pack by using it in your power tools and the cells will be balanced at the bottom, just like you've set it up at the start. And then you can charge them again without balancing, using the RC charger or a lab bench power supply with adjustable voltage, set to your determined end of charge voltage. By doing that, you make sure that all the cells, even though they're different because their different states of degradation, are in balance at the bottom of their voltage range. This is a bit more work at the start compared to top balancing, but there are two advantages. The first, you make sure that the low voltage protection still works properly. The second, charging will be quicker, because a top balance charge will take longer than just a normal charge.

Wow nice. Hi I have a question do you by any chance know how you can dewalt battery bms reset? I replaced single cells but unfortunately bms doesn't allow to charge them.

Where's the balanced board battery fix you mentioned for 2nd half of the video?

You can get the DIY kit cases with the larger balancing board too.

This is just brilliant!! Thank's a lot!

Excellent info ! Thank you

Excelente tutorial maestro, buen trabajo, gracias por compartir sus conocimientos y experiencias, un saludo cordial y por supuesto un merecido like desde Narón (Galicia)🔝👍🤓

Hi, Great video. Is there a link which will tell me the wiring of the balance wires to the batteries?

Well Done Thanks for sharing

Great stuff. You should take a look at the dewalt flexvolt batteries. I suspect they have the same problem. Would like to see you do a mod to those.

I bought Makita first gen LXT lithium cordless tools in 2007. Quite a few of those batteries died within 5 years. Makita learned that battery lifespan is important to construction professionals. They rolled out second gen lithium batteries, gave me two on goodwill warranty. I bought many more. Have only managed to kill one of those over ten years. My fault, too.

Well done nice experiment.....

I am very impressed 👍

... pity you didn't flesh out the Makita equal balance board with bricked BMS - though I picked up what solution was implied.

great piece of electronic improvement, why dont the manifacturers do that ?

Thats a great idea!

I love it! nice work sir :)

I have many Makita 18V tools.. and no problems with the batteries !

How can this device discharge without a cooler for Heat dissipation?

It would be so nice if all that was integrated into the makita charging station. To adjust the charging speed would also be nice, so you can expand the battery life.

Great video!

I'm charging each cell of a Wheatley 6ah pack that has gone dead in hope that when they are all charged to the same voltage the Makita charger will charge the pack again... So far I'm at 3.43v - 3.7v. trying to get them all up to the 3.7v mark. When I started 4 if the cells where reading a 0 voltage. But they all seem to be holding a charge now. The pack indicator is now saying 60%. Is this attempt likely to work? Meany thanks advance 🙏

The JST-Hx is that a 6s pin ? And not a 5s pin ?

Great video

I wait for your Solution for the Big Mainboard with Cell Balancing. I have change the cells but the Charger blinks and Chirp the all time

excellent!

I have a similair problem with my Parkside battery. I connected it to my cellmeter 8 and it recognises all the cells and I see disbalance between the cells. When I hold the dischargge button it double beeps and doesn't go into discharge mode. What could be wrong?

Y is it heated so much plus I smell the plastic burn smell and so stopped after the light just showed in 2nd step which it needed for 3rd step light to be fully charged?smell not normal?

THANK YOU YOU SAVE MY MONEY!!!!!!!!!!!!!!!!!!!!!!! Video is AMAZING!!!!!!!!!!!!!!!!!!!!!!!!!

Have you considered selling those batteries online? It would be fantastic to have them available in our country, especially since they appear to be of high quality and durability. I believe many people will find them useful and convenient to purchase from an online platform.

Why not place inside whole 5S BMS which takies USB C and charge battery directly?

Goes to show you get what you pay for. Cheap aftermarket generic batteries are cheaper for a reason and this video shows why. It was a bit poor that the video didn’t clearly state the battery with the problem was a clone copy and not a genuine Maikta battery.

Great!

Why you choose lipo type

looks like the one without much stuff are knock off not Makita you can tell the spot welder strip

Some of those batteries are Makita, but the one you disassembled is a cheap copy in a size Makita has never sold. Which is probably why it has this problem. I’d guess that all _real_ Makita batteries have the balanced control board. BTW, the B in PCB stands for Board, so “PCB board” is redundant. Like PIN number or ATM machine.

The aftermarket battery is junk, that’s not last a year, my older original battery 10 years still going strong

i have 30 batteries, non of them had this problem lol

might have to bypass the safty board and charge with a bench power supply if possible man

you are genius .thank you so much 🤝

No problem with any of my makita batteries yet . I have been using them a lot for 12 years now .

the title should be "makita 18v rip-off battery has a big problem" !!

use female connector on battery side and the male connector for battery balancer device.

👍

old school 🙃🔋

Its because the bigger 9Ah battery is not a Makita product. Its a Chinese clone which is Makita compatible. Big difference !

This kind of misleading content like this should be monitored, he should change title to FAKE MAKITA Batteries😅

Of course the fake battery has a problem, not Makita 18v batteries!

плату балансера проще впаять

Had mine 5 years 5amp never had one problem

Makita battery. How to unlock and restart the BMS board? After a month of operation, the LEDs began to blink and it would not charge. (as in the 10 second video on the link) The BMS board does not work. The battery is original, new. But I opened it myself after it was blocked. There is no longer a guarantee. / The battery pack itself works, everything is fine with the cells. Temporarily soldered a jumper from the short contact group to the adjacent positive contact group, the battery pack works, but in this option there is no protection for the cells ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-wONqJTCsh5E.html

not an expert but an easy way to make it charge

0:48 Can someone explain to me what that yellow multipin connector on the top of the battery pack actually does? It doesn't ever seem to ever connect to any device which uses the battery...

You are completely wrong. It's not Makita batteries that have a problem, but the counterfeit cheap clones. Your headline is not serious.

jeez

7:10 Why do you charge a Li-Ion battery as LiPo? I guess you don't know what going is.

👏👏👏👏

IT'S A FAKE MAKITA! Use original Batteries!

hahahah! Showing non Makita batteries is hilarious :D

❤ good

HAHAHAHA

Traduire en Francais.Mercie

Lithium cells are wonderful aren’t they! Can you imagine the electronic circuit complexity within the ev cars. Then it goes wrong and needs repairing. Nightmare begins. Bank balance crashes. Realisation that you may have made a big mistake believing the government that evs are the answer to the worlds perceived problems.

Misleading title as genuine batteries already have balancing future. Who will play around with this type of charging while in middle of work on a job site. These type of ideas only good for making videos about but in real life, nobody (who is a real user and not diy user) will play around like this. There are far more important things in life than playing around with how to charge batteries what already existing btw. I did too refresh /repair a faulty battery, but all the effort, time and parts needed did not worth it as the repairing cost was close to a new battery's price. And the ones I repaired was copies. Still have original working battery from 2008.

those are not official Makita batteries

its no way i can do that 🤠

😎👍

Seems like spending a bunch of time and money to make cheap knockoff batteries work. Are you really saving anything in the long run?

Unsafe.good idea

exactly makita charger itself destroy the batteries. The makita charger doesn't charge and shows the batteries have problems. I tested the batteries in severals makita chargers ... the same ... the lights of the chargers flashing, saying the batteries are broken. Well ... i put the batteries in a cheap chinese charger ... BINGO ... is charging. So ... i sold the makita charger and i have 4 years charging just with a cheap chinese charger. Simple. So ... fu_k the Makita Factory, fu_k the designers of the Makita batteries

All the stuff needed & time it takes.... aint it better 2 just buy A new battery?

fake makita problems should be the name

Makita 9AH 😂😂😂😂 clons not original dont misliding

First off that’s a counterfeit or knockoff cheap copy of a Makita 18v battery and nothing to do with genuine Makita. I’ve seen these cheap copies overheat and burn on site from normal use. Always use the original Makita for durability safety and reliability. There is no substitute.

title :makita 18v battery has big problem video: lets add bms to knockoff makita battery 9ah ones keep dying! misinformation here is next level..all geniune 18v line up have bms built in and they have just 6 ah battery using samsung or panasonic or sony cells.....better inform ppl correctly

No one has time for this

I have owned 2 makita drills over the years, they are the 2 worst drills I have ever had

Nice clickbait title. Obviously those are knockoff batteries and with low price, comes sh*t quality. Same other way around with knockoff tools for Makita 18V batteries.

And who has time for such nonsense when you can order a new BMS without a battery charge counter? there are even simpler solutions.

Makita battery has a charge counter, after a number of cycles breaks down.

Makita never produced three-row batteries, a video for idiots.

Unlike Makita, Hikoki and Bosch batteries, Milwaukee batteries can be unlocked. The intelligent Milwaukee charger, after checking all Li-Ion cells, reactivates the battery's electronics. Yesterday I received 5 pieces of "defective" Milwaukee M18/5Ah batteries for free. After two hours, all batteries work like new without changing cells, BMS and soldering iron!

Дам совет:не покупайте аккумуляторы на китайской али-помойке!!!!!!!-там теоритически не может продаваться оригинальные аккумуляторы!

Ain't worth it. Makita is garbage

Some misleading comment in this video. Your 15 cell pack,with a 0.11v imbalance,wiil NOT cause the tool to shut down.