Are All Drill Batteries Balance Charged? (Includes Teardown!)

[@jimkennedy8327]

As a person who has very little knowledge about electronics I still have batteries that do not work with the chargers that I have. I wanted this to be able to help me solve this problem but you are talking above my level of knowledge.

[@ronalddhs3726]

What I don't like is that a lot of these batteries, do not have over discharge protection (they rely on the tool for that); that makes my "using them for random things" a bit more of a pain. Nice video... Thanks :)

[@JohnBailey39]

Which is why people use separate battery management boards. Then no problem, even if the cell is already protected. You do need to use the right one for 1, 2 more cells.. Then all protections are present. Using a bare Lithium battery is asking for trouble. A short, over or under charge, and suddenly you have a dead battery, or a smoke machine. A single cell Lithium charge/protection board costs pennies from usual Chinese suppliers, and has a handy micro USB socket for charging.

[@cinialvespow1054]

@@JohnBailey39 us in the fpv racing / freestyle drone hobby use bare lithium polymer packs with zero battery management systems besides our own etiquette all day 😅😅😅

[@JohnBailey39]

​@@cinialvespow1054 But you also WATCH the performance.. Yes? So you are the BMS. You know roughly how long, and how hard to push the battery. Meanwhile.. Did my Bluetooth speaker run for 4 hours or six already. Don't care. When the battery light comes on, I can just plug it in.

[@MarkDonohoe]

😅

[@Mchacz8008]

​@@cinialvespow1054 Well, drone batteries are not known to be very reliable 😅

[@ThomasReesbeck]

Great video. I took apart a Makita 2.0AH 18V. It is battery balanced.

[@drescherjm]

I know that 18V Ryobi batteries are not balance charged or at least the ones I have repaired were not. For these the repair was to bring the one cell that was out into the proper voltage range. One ones I did not end up repairing the cell voltage on a single cell was actually a small negative voltage. I need to get a replacement cell of the same type if I would fix that pack.

[@peterthinks]

I think the board just imitates the readings from a balance charge lead on a smarter battery pack.

[@stevesfascinations1516]

Good for you for following up. I enjoyed the teardown, I cringed when the knife came out....

[@SimpleElectronics]

I live my life 1/4V at a time....it's like when you are a quarter volt overcharged, you're the only thing that matters!

[@raymondbabin2764]

I have been harvesting 18650 cells from Makita packs for about 6 months ( at least a hundred packs) quite a few were 6ah. All have balance leads except 2 that were cheap Chinese repacks that look exactly like the one in the video.

[@Tegelane5]

5 cell slim original Makita Bl1815's don't have every cell monitoring. Only the "first" cell is checked, probably those knockoff's copied the BL1815's or first 1830's. Schematic fits straight on too.

[@guzmanpatriot]

Is it possible to add a balancing board to it?

[@SimpleElectronics]

If you want to make your own or buy a makita branded one, sure!

[@trolojolo6178]

@@SimpleElectronics No need! You can buy cheap boards with balancer included

[@dmwtech4495]

Lion batteries can be charged without a balance charger, but the cells MUST be matched. Matched meaning capacity, voltage, internal resistance, cell type and chemistry, and batch. this is not the best way to use Lion cells. the problem begins as the cells age and degrade. at this point they will not be matched and they begin to vary in capacity and voltage. this is when they can start to be dangerous to charge without balancing. my 2 cents worth

[@piecetoyou8285]

When testing with multi meter on positive and negative be for dismantling it was showing 15.34 volts,but refuses to charge with a blinking red and green light on the charger. once opened and testing from corner to corner its showing slightly over 20v. Each battery is testing at just over 4.10v , so all good. they are Samsung I noticed in the far corner where that black negative lead goes the plastic has melted and part of the metal has discolored as well as the negative wire leading to it. Now if I replace the negative wire and tidy up the slightly burnt nickle battery tag, with new nickle and spot weld it `do you think it should start charging, Or would there be something else I need to check.

[@alandaters8547]

As an RC hobbyist, I wondered about balanced charging in tool battery packs. We have a new Craftsman V20 LiPO powered trimmer which has only been charged twice. It has 4 contacts for charging, labeled B+ B- NTC ID. This should not be able to support balanced charging by the charger of its 5 cell LiPo pack. But when I opened up the pack I found 4 robust connectors running from the connection points between the cells to the PCB. The individual cell voltages were very close - 4.019v down to 4.014v. Perhaps these packs have balancing circuits inside the pack?

[@SimpleElectronics]

Some of them do, but others just check the cell voltages and brick the pack if one cell goes too low

[@justinhummel5613]

Interesting... I want to take my makita batteries apart now and see if they have balance charging, wether that be a balance board in it or the charger does it. I have my doubts though now.

[@matthiash.4670]

The original once don't have this cheap Chinese BMC board. Mikita does at least per cell monitoring, maybe balancing too (I'm not fully sure). There's a "better" Chinese BMS too with per cell monitoring, but in pre-build packs is most of the time this cheap type shown in the video.

[@RPBCACUEAIIBH]

7:17 That connector is for data, not balancing... I'm currently repairing 2 of the 36V original makita batteries (old BL3626-es, with little capacity left), and it has the same number of connections. For a 10S2P pack that I'm working on, 7 pins are not even enough for balancing. It would require at least 11 pins, or 9 if the main + and - terminals are used. That being said, the cells inside are all within +/- 0.01V from each other, and all 11 terminals are connected to the 2 main boards, which are on the sides, and connected to each other via a flat flex cable. (There are tons of components on both sides of 1 board, including a micorcontroller and a BQ77PL900 chip, and some passives on the other board.) The 3rd board on the top is just a breakout board, with no components, just connectors on it...

[@Stevesbe]

I've never seen any power tools laying on the side of the road

[@ppn7]

does the original 3.0ah makita has balance charge?

[@JoanWorth-y4q]

Can I charge one pack without taking them apart ?

[@drfailbucket]

Very nice video 👍 It would be nice if you would teardown a makita charger (a real one) and go in this way of detailed information. Would be quite interesting to see for what the yellow plug is really needed and how the Charger overall works and why it's so bulky, bc I another video you showed that it doesn't need that much to actually charge these batteries P.s if you won't "waste" one I would spend one to you

[@SimpleElectronics]

I would love one to teardown, but before you send it, check how much shipping will cost; it's quite a lot to ship stuff to canada. My PO box is in my channel information

[@drfailbucket]

@@SimpleElectronics No problem, it's fairly cheap. I'll send it right tomorrow to you 👍

[@drfailbucket]

@@SimpleElectronics Also is there a way to contact you more personally? For sharing the Shipping information

[@SimpleElectronics]

My email is in the same place you found the POBox info, thanks!

[@bwselectronic]

Sure. I'd like to see a capacity test. The blue wrapper on the batteries looks authentic

[@georgef7754]

Capacity test please.

[@tomgrant6563]

I have a dismantled Makita one here that does have balance connections. they are tapped in between each of the series connections between the 5 pairs of paralleled cells.

[@diyelectrovids6536]

Thanks for the info, I have a similar battery pack that has no balance charging.

[@derekgoffin5807]

I want to recharge my dewalt 18 volt battery whilst away in my camper. I do have a small inverter so I could use my mains charger, but I also have a usb c pd charger which charges up to 20volts at 5 amps. The camper leisure battery is a diy Chinese cell leisure battery 200 ah 13 volt. Do you think I could charge from the usb c pd?

[@Chriva]

If a Li-Ion battery doesn't have cell balancing, it's unsafe and shouldn't be used. The slightest difference in cell capacity will avalanche and kill it prematurely. Why: Every time you discharge the pack, the weakest cell will go to the lowest voltage. = more wear (and this is not even the worst since normal packs behave this way too). The real killer is when you charge it since a lower capacity cell will charge faster. What do you think happens with its voltage long before then other ones has reached a steady 4.2V constant voltage state?

[@SimpleElectronics]

This is correct in theory, but don't forget that cells pause their voltage increases (at low currents) at near to 4.2v...it takes a lot of energy to raise their voltage from 4v to 4.2v and thus won't necessarily overcharge. I think you would be surprised how often this practice is used.

[@bobikbobikowy5458]

I got fake makita battery looking exactly like yours but it have balance charging (wires connected to all cells and they had exactly 4.04V). Bought it in poland for 20$. Package says 4ah but it have samsung inr18650-13Q inside, so only 1300mah per cell and 2.6Ah for whole thing. Poor capacity but at least genuine cells with balancing should work fine for some time.

[@guzmanpatriot]

Hey man can you put a link where you bought the battery? I would love to try them out, thank you!

[@Coyote973]

You are reviewing a fake Makita battery. I don't see the point on analyzing whether it is balanced charged or not, since it is dangerous and can even explode not comparable to the original ones.

[@matthiash.4670]

Some more Information: The 3rd pin is the charging pin. The charger will charge the pack over this pin. The thermal fuse is just to cut off charging current in some critical Situation. This ist found on this cheape chinese BMCs like the one shown in the video. You can find better BMCs, even with per-cell Monitoring, like this: www.aliexpress.com/item/33007327940.html?spm=a2g0s.9042311.0.0.27424c4dr8ofna I used this one few time, since I have some good quality cells, so I used them to build packs for my power tools. And by the way cells: There are just a Hand full of manufacturer building high-current cells required for power tools. The cheap chinese packs include "standard cells" because they are cheap and have a quit high capacitance. But they are not designed to drive high output currents and will degrade fast by this abuse. This type of cells are commonly used for notebooks where capacitance is key, not output current. In compare the original Makita packs you will find notceable differences, for example you can see this in this video: kzbin.info/www/bejne/hn-5c5WFhr-KbJY I did some high-res Pictures by my own some time ago, if you may interested… The original once use per-cell Monitoring. I'm not sure if it's balacing too. I never messured the current between the sense wires. But be aware of trying: Orginial once have a "kill switch". If you remote the BMC from the cells, even just one sense wire, the pack won't be charged on the orignial charger anymore! To swap the cells of a orignial pack to have temporarly bridge an other pack to this one, with all single sense wires. The yellow connector is in fact for transfering pack specs, yes. They do this digital. The pack temperature is also transfered by this pin. The original packs have a 4th pin. This pin is behind the 3rd one. As first it Looks like this is a common pin, but it is not! This pin can give the power tool a Feedback to turn off if the pack gets hot, draws too much current, cell voltage is dropping too far, etc... this safty feature is NOT present on ANY chinese pack! So with a heavy power too you can drive this cheap packs to death quite easily...

[@lgwwin]

this is good info. but is the pin for charging only, balancing or just monitoring the battery health? It seems there’s no need to communicate with the machine because the battery can just stop outputting if voltage gets low, no need to ask the machine stop drawing current. If this is the case, I will be more confident to figure it out if the pins for balancing, no need to worry break some communication protocol.

[@matthiash.4670]

@@lgwwin The battery won't cut off the current. Most types don't do this, especially high-current packs. You need to add switching circuitry, so this leads to added FETs with a given Rds-on and therefore a power dissapation, and therefore additional heat in the pack, especially in heavy-load situations where the cells are already getting hot by itself. So normaly no manufacture will add a cut-off circuitry in there (high-power) packs (you will most likly find this type of circuitry in lower-power 12V stuff). It would be a kind of bad design, so to speak. Thats why most of the systems use additional connection pins to communicate a shut-down requirement to the machine itself. This way they don't add additional thermal constains to the battery pack construction. All Makita packs and machines do this that way. All chinease know-offs don't handle this case. Both: batteries and machines. But most machines turn off by itself if the voltage drops below a certain level. So normaly the batteries, even cheap knock-offs, won't die (early). But the 3rd pin (not the 4th in the same row mentioned above) is used by the charger only. On the orginial packs this is internaly connected to a trigger-fuse (a type of fuse that can be blown both by over-current or by an external trigger impulse), so the pack can "blow up" the fuse internally if the charger won't stop charging even if the cells are starting to overcharge. This construction guaranties that the pack won't catch on fire, even it the charger gets crazy. Cheap battery knock-offs sometimes try to handle this with a thermal fuse. Other cheap packs don't have this safty circuitry at all. They don't address the possibility of a damaged charger. Even the thermal fuse variant is not really save. If the cells getting hot due of over-charge, they can run into thermal runaway. Especially because all packs I've seen so far uses 125°C thermal fuses. Befor they start to trigger the cell internal temperature is already way higher. Depanding on the cell chemistry the TR point starts in a range from 130°C to 170°C. Not really a save headroom. The cells won't get balanced in the packs. But they are monitored "per cell". This monitoring is don't by the pack circuitry and is communicated by the additional yellow connector to the charger. So the charger can stop charing, if cells are getting overcharged. Also the charger ca detect overheated or damaged packs, which is also communicated by the yellow connector from the pack circuitry to the charger. So the original design is quite save and versatile. Be aware of cheap knock-offs, they all have serious safty drawbacks - some more, some less.

[@sunny3560-e6y]

At least the Ryobi 1.5Ah battery is not balanced, i just manually balanced a battery made in 2016

[@jjustinengineer]

I recently purchased a used Ridgid Li Ion battery. The battery only shows 2 bars out of 4 so I attempted to charge it with my bench power supply using its current limit function (set to 200ma, voltage at 20v) until the charger arrives. I wasn't able to get any current to flow into the battery using the two outside terminals which is what the tools use (the tools only have two terminals). There are 4 terminals on the battery. You can draw current from the battery but can't charge it. My conclusion was that the battery charger puts a signal on one or both of the other two battery terminals which enables current to flow into the battery. When I receive my charger, I will be able to determine what's going on.

[@villehietala9677]

Capacity test alone wouldn't tell the truth about those cells. Power tools need a lot of current and cells ability to give it matters. Capacity and max current are things that cell manufacturer has to balance between for the planned usage. Those cheap batteries could (but I doubt it) have the stated capacity, but only when discharged at couple amps. That might be enough for random usage at home and the cells could stand up for those two screws with small driver per charge, but bigger tools and/or needs at construction site would kill them permanently before first coffee break. All the real tool manufacturer batteries I have opened have had small leads connected to every bridge between cells. Even some cheap ones that I tried to resurrect my old Hitachi tools with, before changing everything to makitas. Atleast in older makita batteries, there were counter for under voltage detections. If you drained your battery three times to under voltage, it would not charge in a official charger anymore. I have tried to remember that possibility and stopped at the first battery cutout and not to try to screw that last screw with the tool dying five times while doing so. I have not yet killed any of my makita batteries, but I still hesitate to give my tools (or actually batteries, tools are free to use for my friends with their own batteries) to others unattended.

[@MrDexi87]

Hm , my 1840B have balance charging , maybe new revision with 2x 50A smd fuse.

[@ahmadfirdausbinyahaya8063]

Is this fake/imitation Makita bateri?

[@SimpleElectronics]

yes sir

[@pfh02]

👍

[@hondafreak8613]

I capacity tested chinese 18650 claimed 3000mah. They only took 350mah to full charge.

[@SimpleElectronics]

these will take more than that for sure - but how much more is questionable - btw I like the TL wheels in your display picture

[@Ist_Geheim]

Sorry, but as you used an aftermarket battery for your test, in my opinion your test tells us nothing.

[@dwikey_98]

he is talking about balanced charging function from the BMS in makita battery tools.. using aftermarket battery or from the makita one, don't tell any difference becauhe he is talking about the balanced charging.. if the bms from the makita has balanced charging function, all voltages from battery can match one another.. no matter what kind of the lithium battery you are using, if all the battery cells which hooked to the bms in a good condition, and all of them have same voltage it indicates the bms is working.. that is whole point, not the condition of the battery

[@nelchan2421]

18650 20r mean 20r 2000mah

[@scot-johnson]

Metabo batteries balance charge from the factory

[@henryairconcepts2999]

Looks like you have a good quality makita battery knock off

[@greg4272]

You dont even realize, this is a fake makita battery!

[@SimpleElectronics]

did you not even make it to the 3:00 mark?

[@greg4272]

@@SimpleElectronics No, and did not even care. Pointless.

[@SimpleElectronics]

@@greg4272 "wow everyone - @greg4272 thinks that it is a bad idea to breathe! I'm not going to check that he said that but I will comment it on his work!"

[@greg4272]

@@SimpleElectronics If only you could word a sentence that has some sense at all!

[@SimpleElectronics]

@@greg4272 Sir, this is a Wendy's.

[@bobbyhutcherson1333]

So, this battery is a knock off ? Well... it's no surprise that it's not balance charged. But that's what those terminals on the REAL battery are for. So you may not "buy it" but that's because you buy GARBAGE batteries.

[@ruslanmiskinov8790]

never seen build like this before. my dewalt,rigid and milwaukee batteries come with proper BMS, that balance cells. so its true,that you get,what you paid for. this battery pack is a garbage. not safe,not reliable.

[@madaniyassine1285]

Fack batterei

[@jamesfin6039]

That is not a makita battery

[@jamesfin6039]

Is a Chinese copy

[@SimpleElectronics]

Pretty sure I mentioned that in the video