Inside the ALDI Ferrex 20/40V battery charger with schematic

An internal exploration of the charger used for the dual voltage Activ Energy 20/40V power tool batteries.
The circuitry breaks down into two distinct sections. A fairly conventional power supply and a charge control system. The main oddity about the power supply section is that it has extra voltage regulation for its controller due to the variable output voltage range that is adjusted to maintain a constant charge current.
The low voltage control circuitry is based on a chip marked Lideal 1508 B9417001V89.
It has the facility for bidirectional communication with the battery pack, which has two sections with a common master control chip. It can also monitor the pack temperature during charging.
When the pack is charging the controller can adjust the power supply voltage to maintain a constant current via a sense resistor. Each section of the battery has its own MOSFET so it can be charged independently if needed, especially for basic balancing, although the batteries themselves don't seem to have individual cell balancing.
The tools that use the dual voltage batteries simply connect the two battery modules in series or parallel as needed. They are enabled by the detection of the battery thermistors, which are also used by the battery itself to signal that charge is low and stop the tool operating.
If you enjoy these videos you can help support the channel with a dollar for coffee, cookies and random gadgets for disassembly at:- www.bigclive.co...
This also keeps the channel independent of KZbin's algorithm quirks, allowing it to be a bit more dangerous and naughty.
#ElectronicsCreators

[@amorphuc]

Thanks Big Clive. I'm constantly amazed how you can work out these really complex circuits. Very cool!

[@MichaelOfRohan]

"Really" is a relative term. Sorry, but Im here to piss on this comment. Grow up. Read a book.

[@pepperpepperpepper]

@@MichaelOfRohan Go feed a baby bird?

[@alexmarshall4331]

He could be bsting us of course...just a flow of ad libbed (or even scripted) techno flubber...we'd love that even more!!! 👉🇬🇧👈❗

[@enoz.j3506]

Like any trade ,if you have many,many years experience,it all makes sense. The unique thing Clive does is the photo & reverse engineering,that's what makes this good viewing.

[@tncorgi92]

@@alexmarshall4331 like the "turbo encabulator" videos... those are a hoot...

[@Nono-hk3is]

Nice job Clive! Unfortunately we are well passed the age where manufacturer's acknowledged their responsibility to provide schematics so that their product can be repaired. Your work will probably never be acknowledged for how important and useful it is, for right-to-repair and for practical education.

[@tonysheerness2427]

You own nothing, you only get to use them while they work. and you are supposed to be happy with this.

[@tncorgi92]

@@tonysheerness2427 As new owners of EV cars are discovering.

[@John_Ridley]

@@tncorgi92 Or any other kind of car as well. Try replacing a module in a Toyota without factory programmers.

[@tactileslut]

@John_Ridley I'm keeping my '90 Toyota and '89 Honda.

[@rhodexa]

We are still fighting with dead DJI batteries, they loose charge and enter in panic, and there's no way to recover them without the proprietary Hash Key they used to seal the pack. _(just adding to the stories)_

[@mfx1]

I've used pretty much the same method of reverse engineering for years but I use different layers in a paint package like gimp, I align and scale them so they match and can then use layer transparency to fade between layers I then add additional hand drawn layers to trace power and signal paths using different colours for top and bottom tracks and then colour code significant solder pads (mostly power/gnd).

[@krnlg]

Cheers Clive, your videos kicked off electronics as a hobby for me. Now I have a room full of junk and very happy with it 😄

[@user-gx6jb6wc5g]

Thanks. Good to hear you're enjoying electronics.

[@simontay4851]

wow, that was amazing reverse engineering work. I have one of these and didn't know it was so complicated. You have a lot of patience.

[@jkobain]

And curiosity, indeed.

[@grantrennie]

Am awake so I will watch this thank you Clive 👍

[@ow_will]

non-member gang lol

[@bumpkinrocks]

I can't sleep either, I'm in👍

[@Palmit_]

@@ow_will same. :)

[@Damien.D]

Just finished some work, just as I was wrapping my things up, this popped up on my notifications. Sleep postponed accordingly :P

[@kimbledunster]

Lunchtime on Sunday for me!

[@tweed532DaveH]

Well like many others, 'Thank You' for these analytical breakdown series. Approaching '70' (🙄) in a couple of days and I reckon I've learnt more in the last few years, regarding fault finding and repairing items than I did in 2 yrs at Bangor Uni doing an electronic engineering degree, way back in '74 before realising I was 'practical' hands on rather than having to regurgitate theoretical formulae. Need those note books published as a Calender with a 'circuit/hack a day' option!!! Cheers 🍻👍😃🇬🇧

[@tncorgi92]

Happy birthday, fellow geezer

[@jkobain]

I wasn't brave enough at the start and just watched some short videos which YT kept suggesting me more and more. Then I found a video about Christmas lights in Glasgow. And I subscribed, and never had any regrets, that's for sure: you keep educating with your entertaining, explanatory, and therapeutic videos, every time. Thanks!

[@williamromine5715]

Honestly, Cllive, I can't imagine anyone not subscribing to your channel. It has something for everyone, from me, who hasn't a clue what you are talking about, to those who not only understand what you are saying, but also can make suggestions! And, most of all, your subscribers are the most gentlemanly or lady like of subscribers that I have seen on u-tube. That is quite an accomplishment in the internet world, where everyone has to prove how brilliant they are by insulting everyone else. Keep it up, you are doing something right.

[@JLneonhug]

Thank you for including what's most often cause for failure. Please continue to do that in the future! I have a baby milk bottle steamer I was diagnosing recently, it clicks on but switches of nearly instantly afterwards. I suspect its likely a faulty relay as it's a pretry simple device (rectifier, relay, thermostat jobby with few caps/passives here and there). It's refreshing to hear experiences from others too.

[@eDoc2020]

I'd guess power supply. The extra current drawn when the relay kicks on would pull down the output voltage. This has happened with some of the failed products Clive has shown. Likely a capacitor, and if it's a non-isolated supply don't forget to check the dropper cap.

[@YeOldeJenkins]

Coincidentally I was repairing exactly the same thing (baby milk warmer) with exaclty the same symptoms a few years ago. As @eDoc2020 suggested it turned out to be the dropper capacitor. After swapping that the unit worked again. I would think that dropper capacitors are pretty robust but in my unit it was pretty close to the heating plate so maybe the frequent warming and cooling made it fail? Took me a while to figure out. Where were you @eDoc2020 back then? Could have saved me some time 😉

[@user-gx6jb6wc5g]

Does it have a simple capacitive dropper, that's a very common failure mode with them, where the main dropper capacitor decreases in value over time until it can supply enough current for basic circuitry operation, but not the relay. When the relay clicks on the voltage drops and the circuit resets. If iot is that then it's a very cheap fix. (Change that capacitor for a new one.)

[@JLneonhug]

Thanks all! I'll order a some caps to try. I was sure I tested it prior and it didn't seem to have an issue, bringing it out again today, it seems to not measure up properly, doh! It was/is very temperamental to be fair.

[@JLneonhug]

@@user-gx6jb6wc5g small update, caps arrived, swapped it over and works like a charm again, thanks again Clive and others for reply :)

[@thomasives7560]

Thanks for the elaborate reverse engineering work! Chargers and support hardware for cordless tools are just as critical as the tool itself, so it is great to have a good understanding how they work. Your efforts help the entire electronics community, please keep on doing what you do. Happy new year and cheers for all the great video content!!

[@noakeswalker]

Remember when a rechargeable drill just had some NiCds and a switch, and the charger was a transformer and a resistor for 'constant' current ? This Aldi one seems insane. Thanks for delving into it though Clive :o)

[@user-gx6jb6wc5g]

NiCd cells were definitely much simpler to work with, but the advantages of lithium are huge in comparison. Just a shame they're so critical to work with.

[@Slicerwizard]

And you remember how crap those drills were??

[@user-gx6jb6wc5g]

@@Slicerwizard My old Ryobi tools are completely different with a lithium pack. Immensely more powerful.

[@noakeswalker]

@@Slicerwizard Yes I do. NiMH were better, and the chargers were still fairly simple and reliable. Of course Li ion are way better in performance terms, and charging IS more tricky, but this Aldi charger and double battery seems to be inviting failure with its high parts count. Two processors really necessary ? They aren't even measuring the temp of BOTH batteries in the pack according to Big Clive.

[@TopEndSpoonie]

Wow, that really was a LOT of work. You probably needed a drink after that one. Thanks Clive.

[@jimsvideos7201]

I wouldn't be surprised if we start seeing fans on those chargers soon. Good gravy.

[@Cloud9ninja]

I have a couple which do have fans in them.

[@justme5384]

Makita LXT and some CXT chargers has fans that cools the battery pack

[@gregorythomas333]

Holy bat shit Batman! This is a very complicated system...thank you for going through it all so completely :)

[@jkobain]

Oh, fock, it really takes a lot to reverse-engineer these things. Very well done, Clive, and thank you so much!

[@Damien.D]

Wonderful work on explaining this puzzle of a schematic. Was waiting for this teardown, after seeing the already complex cojoined twins batteries pack. The software on all the chips must be equally complicated. I hope it's well debugged, considering all of this switches potentially high currents... I'm surprised that there are no thermal sensing of any kind inside the charger btw

[@user-gx6jb6wc5g]

All the thermal sensing is in the batteries themselves. The charger can detect overcurrent and regulate back to within its comfortable range.

[@SeanBZA]

I would say more like a small on die ASIC area with all the logic functions pretty much hard coded in, not a microcontroller per se in that you can reprogram it, just likely has some Eprom on die that allows an OTP setting of function and parameters like battery voltage, current and such.

[@erlendse]

@@SeanBZA Like mask ROM microcontroller or analog ASIC. Seems not too unlikely, cutting the signal to the opto would bring up voltage if it works like the usual controllers. Aka continous control is needed to avoid excessive voltage, and no software to crash helps in that regard.

[@brauchmernet]

Hmm, I would agree but why bother and have the programming pads on the pcb? This charger has been sold/produced in the 100k+ counts across the world.

[@SeanBZA]

@@brauchmernet Because the chip likely can be used in a number of chargers, and the board as well probably has a few variants for different brands, all with slightly different battery capacities, so having the controller go in blank, and then programming it as it is made is cheaper, as you can change mid run to another brand with little issue, just finish the run and clear out the line, then put the new program in and carry on. One might not have a dual voltage battery, one might have a different battery monitor, and so on, so the ability to redo the board itself is useful, plus adds almost zero cost to the board, as even if the micro comes fully programmed and OTP redoing the board to remove the pads is not worth the extra expense. After all you have only 5 extra drill steps, not a big deal with 200 holes already, and no need to expense out the new PCB layout, the new screen masks and such, just use the existing till it wears out, and make it again from the original Gerber files.

[@faridsafazadeh1137]

thank you so much. It is amazing that you have been around long time and still constantly getting better and better...

[@phils4634]

For what is a "relatively" inexpensive charging system, that's a very complex device; mind you when you did a teardown of the (albeit single-voltage) Ryobi charger a few years back, that too was insanely complicated! It amazes me how such complexity (and durability too) can be so comparatively inexpensive!

[@DavePoo2]

You caught me off guard, I nearly spat my drink out when you said "death beam capactitor" - 400V capacitors will forever be known as such

[@user-gx6jb6wc5g]

This stems from a KZbin conspiracist who showed the inside of an ordinary LED street light and announced that the 400V capacitors were for powering the 5G directed energy weapons.

[@DavePoo2]

@@user-gx6jb6wc5g That's convenient, as it means that "Death Beams" can be built with common parts found in just about any PSU.

[@kimchristensen2175]

RE: My analog posse guess: The Opto isolator is the feedback loop for the switched mode power supply IC. To maintain stability, you can't have much of a phase shift in this loop. That's what those two capacitor/resistor networks are for. The MCU alone would introduce too much lag after processing the ADC inputs for cell voltage and current and before outputting a corrected DAC current. (The cathode of the Opto isolator's LED possibly being connected to the output of an Op-Amp/DAC combo in the microcontroller and not a digital pin). This would allow the MCU to do the proper lithium battery charging method of starting out in current limiting mode and switching to voltage hold mode (4.2V per cell) by varying the current into the Opto isolator's LED. It stops charging by turning off those two P-MOSFETS shown on the previous pages. The MCU can't stop charging by fully turning ON the Opto isolator's LED, because that would kill it's own power source, and it would end up in a nasty reboot loop.

[@johndododoe1411]

I'm guessing that (mostly) pausing the switch mode supply is to enter a low power mode where the MCU runs from the capacitors while sensing battery insertion and possibly doing periodic battery top up if a battery is left inserted for days. In such a low power overall regime, the MCU can run from it's internal low frequency clock, PWM the leds at low power while doing other work at slow speed. The power supply would be powered on in short bursts to top up the capacitors used by the MCU.

[@abitofabitofabit4404]

The datasheet of the TinySwitch-III lists its first product highlight, "Simple ON/OFF control, no loop compensation needed". That's not unusual in smaller low-cost flybacks. The optoisolator in a bang-bang, ON-OFF control loop is less critical, less expensive, and less vulnerable to aging than one used for analog transmission; a PC817 would do. I assume this ASIC, if it is a micro, incorporates most of the control circuitry of an SMPS, or has a complement of autonomous peripherals and configurable logic cells, and event buses to glue them together.

[@kimchristensen2175]

@@abitofabitofabit4404 Ah OK... So essentially the control loop is a low frequency (Relative to the switching frequency) PWM signal...

[@abitofabitofabit4404]

@@kimchristensen2175 Right. In the event it holds its breath and passes out, nbd, that's self-limiting.

[@johnmorgan1629]

Can't find myself subscribing to you because of your efforts here, as I subscribed years ago.

[@ComicalPhrase]

Been watching a ton of these but this one got me to finally subscribe. Thanks for all your efforts!

There must be an overcurrent protection in the battery packs too. It kicked in as it was used with the circular saw on hard wood. Nice review (as always), i'll store it well in case something goes wrong with my charger.

[@ricoma6037]

I must say thank you again for doing such a wonderful job of reverse engineering the design. It's not easy, but you make it look easy!

[@ricoma6037]

I said above prior to your acknowledgment! 😆

[@joaoliduario]

Thank you Clive! THIS VIDEO WAS AMAZING! I LOVED IT! Very well explained. So detailed and clear. I can't imagine how long it took to reverse engineer everything. You are just the BEST! THE BEST!

[@grahamrutherford8800]

WOW! Big Clive, you are one magician. coffee coming your way.😳

[@ThriftyToolShed]

Great video Big Clive! I love working on tools and I really hate to see how difficult they are getting to repair. Usually potted and complex. Sometimes very complex from EGO that has a communication between the tool and pack or Ryobi which has one of the most complex batteries because it cuts the power with Mosfets inside of the pack itself for the cell monitoring and cut off. It's a weird TTI thing, the AEG (Ridgid) also has this as well as the 18V and 40V Ryobi packs.

[@Mark_B544]

Great interesting videos as usual big man thanks

[@stuffoflardohfortheloveof]

Bloody hell Clive, that was brill! I've now lost the ability to walk as I've spent longer on this toilet than originally intended 😆👍

[@user-gx6jb6wc5g]

It's OK. The pins and needles will wear off quickly.

[@SeanBZA]

Will say the main microcontroller is simply using the optocoupler to change mode of the primary side power supply, turning on the power supply from a low current standby mode, and then turning on the optocoupler via an analogue current to increase voltage when needed, probably a way to lower standby power draw, by having the power supply in standby run in hiccup mode every few seconds to keep the rails chsrged, but drawing little mains current, then when the battery is connected and enabled it ramps up the feedback to get the current flowing, using current control initially to limit the charge current, then when the voltage is higher and current drops it switches to voltage control. The 2 secondary side senses likely one is a power on reset only, and the other is the feedback of voltage of the battery pack, it likely alternates between each half of the pack every minute or so, so it can sense when each half is approaching full by the lowering current, then waiting for the other side to do the same, then switching both to voltage monitoring till they both show full, or the BMS tells it to finish charge by either internal cell voltage or by NTC reaching a high cut temperature. That package likely has a cheap micro with a separate high current DAC to provide the analogue out, and a few analogue in pins, not some repurposed standard micro but developed specially for these types of split packs.

[@Pwecko]

I know nothing about electricity or electronics, but I always assumed that a battery charger would be a pretty basic piece of equipment. This seems extremely complicated.

[@artursmihelsons415]

Great reverse engineering job and excellent video! 👍 Thanks for sharing and taking all this effort making Aldi series videos!

[@karldavies2954]

Can't sleep, perfect timing 😃

[@devttyUSB0]

Magnificent work! Very interesting and very complicated.

[@MichaelOfRohan]

Mmmmmmm..... "very"... here we go again. Are you a robot? Or are you just copying what the robots do?

[@jkobain]

@@MichaelOfRohan robots do what we do, so are we just robots then?

[@devttyUSB0]

@@MichaelOfRohan wait.. did i miss something? Are my language models not properly trained? 🙃

[@MrEurypterid]

Always a joy, but can I plead for another "Cooking with Clive". I've nearly done myself a mischief laughing at the direct voltage method of cooking food. 🤣

[@EcoHamletsUK]

I've been putting off opening up my Aldi Workzone 12v charger from some years ago, that seems to have failed, I hope it's a lot simpler, so I stand a chance of getting my head round it! This 2 voltage system is appealing when I look at the number of different 12, 18 and 36v chargers I currently have, but if it means a complete loss of all my power tools if the charger fails, and a difficult or expensive repair job, or even the need to replace all my tools, I think I'll live with the inconvenience of a variety of different chargers!!!

[@ConstantlyDamaged]

Voltage divider + capacitor seems to be their standard for voltage sensing-and in particular when to turn things off. It'd be awesome if these micros could be examined to see if it's a digital sense or if they're reading the voltage with an analogue pin.

[@SeanBZA]

Likely some are a simple comparator and use a bandgap reference on chip, while there likely is an on chip mux and single 8 or 12 bit ADC using the same reference.

[@tinfever]

It might be possible to watch the voltage being sensed dip down with a scope whenever the adc connects the sample and hold cap inside to take a sample.

[@SeanBZA]

@@tinfever Likely though to vanish in the ripple and clock noise on the chip pins, as the cheap ADC containing microcontrollers use the same ground as the digital side, and the ground current is full of switching noise of the microcontroller already, as few programmers will take the time to switch the microcontroller to a sleep mode, wait 5us for the noise to settle down to clock alone, and do the sample and conversion, before waking the micro up again. Internally the only way to reduce that noise is to take 16 samples one after the other, and then add them up in a register that will handle the word size without overflow, then simply do a right shift 4 times to divide by 16, to get a slightly better noise figure. Gets you a better result, assuming the noise is going to be more or less random, and thus cancelling out.

[@yup-nope-yep]

Awesome as always Clive :) Thank you.

[@johntickle3120]

Thanks for this Clive I wondered how much tech was going on inside these chargers. I think most of this is to make the charger proprietory to the brand and stop the charging of other battery makes. Looking at 2 different makes most hvae lugs to stop insertion of different batteries.into the same shoe. In conclusion the battery has the cell balancing in the battery pack and each make has different arrangment of battery to charger connections. Why do they make life so complicated. LoL, Job well done.😎

[@user-gx6jb6wc5g]

Sadly, the packs this unit recharges do not have individual cell balancing. Mainly because of the amount of circuitry in them already.

[@Tegelane5]

@@user-gx6jb6wc5g That's insane, I replaced (and doubled with LG ones) noname cells in one noname hedge clipper-and this battery had proper and documented cell monitoring chip inside. Charger was cheapest 20V wallwart with charging light but it worked.

[@eDoc2020]

Some batteries don't have internal cell balancing. DeWalt ones have separate pins for each cell tap.

[@markmurphy3578]

Wow. What a walkthrough! That was pretty deep, but I now feel like I need to do my homework before Monday. 😂

[@ElvenSpellmaker]

Ahh one for the Big Clive Dictionary: _"Deathbeam capacitor"_

[@markmarkofkane8167]

I like that digital micrometer. I didn't know they existed. I want one. Great video!

[@booboyBL]

I’ve had one of those for years. I used to use it at work, as an inspector for an aerospace engineering company. Now I’m retired, it still gets used occasionally. You can get them quite cheaply from eBay, Amazon or Alexpress.

[@clivequinn8978]

It’s a vernier not a micrometer.

[@user-gx6jb6wc5g]

I made a video about the digital caliper a while ago. They're very cheap, but surprisingly accurate.

[@lasersbee]

Wow Clive... That was quite a patient Reverse Engineering project...

[@piconano]

This must have taken you at least a whole day to reverse engineer. Much appreciated. Also, I too think this chip is an ASIC that has a PGA (Programable Gain Amplifier) or a 16-bit ADC, since it doesn't use and external op amp to amplify the puny voltage drops across the 0.05R resistor.

[@Roy_Tellason]

I've run across those transistors that had a couple of resistors built in, salvaged a number of them when scrapping out VCRs. There are apparently a variety of those kind of parts available, seems like they are oriented toward interface applications with different logic families. A datasheet on those might make for some interesting reading.

[@vincefletcher1547]

Love It Clive !

[@ralpha679]

If you bought this recently, this'll be the version manufactured by Varo. I have the slightly older version by Conmetall Meister (which is faulty) so might be slightly different.

[@stevejagger8602]

Ah! 3 microcontrollers! I am reminded of a work colleague who hated the overuse of them. "Why use a microcontroller when all you need is a switch and a relay!" - spoken much less politely. Thank you for the reverse engineering - I find it very satisfying when there is no longer any manufacturer willing to commit to sharing information which is most often not rocket science.

[@bobdoritique7347]

A big merci.

[@frankowalker4662]

Nice work, Clive.

[@dcallan812]

really clever bit of kit. 2x 👍👍

[@whitesapphire5865]

If this level of sophistication goes into an "economy brand" tool and charger, then what goes on in "top brand" kit, like Milwaukee, Snap-On, Makita and so forth? Or would we find the self same arrangements, even if implemented differently?

[@crazygeorgelincoln]

Wow, it's some sort of miracle I got an active energy battery to charge on an (2014) Ryobi charger by blatantly guessing .

[@mousemade1]

Thanks

[@user-gx6jb6wc5g]

Thanks. Greatly appreciated.

[@BPantherPink]

On the right of the frst ski'matic, i see one leg of the Isle Of Man's emblem, dislocated !!

[@royspeakman1157]

Brilliant !

[@TimPerfetto]

Thank you

[@walkingweapon]

Hi Clive, great work! I'm trying to trick a battery leaf blower to run on a bench power supply. It has three spades that contact the battery. Any idea what signal the third contact is looking for? Thanks!

[@christophero1969]

Thanks!

[@user-gx6jb6wc5g]

Thanks. Much appreciated.

[@johndododoe1411]

The layout reminds me of Atmel 8 bit MCUs with their analog capability pins on one side. The RC links between the SMPS control pin and other pins confuse me, however someone from the design team was in the comments last week.

[@radio-ged4626]

It always beggars belief that design has to get so complicated. Why do we need three microcontrollers to charge a battery? Possible answer: To make you throw it away and buy a new one when it fails. ---? I know battery technology design is accelerating and charging circuits need to become more complex to deal with new battery technology... but really? for a cordless drill? Great video BTW, fully appreciate the enormous effort you've gone to, to explain the circuitry. I just like to moan about how things are so difficult to fix these days.

[@kevinjohnson2528]

Go on then, your reward for this endeavour - ive subscribed!

[@Mr_Wh1]

3:55 - Almost sprung the zap-trap right there. Be careful bro.

[@springwoodcottage4248]

Fabulous reverse engineer! As this is so complicated I wonder if in the by & by someone will make asic to simplify everything. It wouldn’t help with repair if the asic are not available & perhaps the stresses are such that asic would fail, but perhaps may lead to more reliability if robust asic can be made. As is the chargers are less than £30 which is amazing value & if one accounts for the cost of one’s time makes repair not economic, but the satisfaction of fixing something & not sending it to landfill is beyond economics. I have now collected a whole bunch of Aldi cordless tools which are such a blessing for my diy work. The sheer pleasure, convenience & safety of being mains free never fails to come to my mind. We live in such extraordinary times when such amazingly useful technology is so affordable. Thank you for sharing!

[@edgeeffect]

I saw those 4 test points in a row and got all excited and assumed they were a serial port or ICSP. I'm not so sure now.... looks like one goes to the opto isolator and 2 to and LED(?).... looks like they're just plain ordinary test points.

[@tmanimal]

There you go, Kiddies........Big Clive does it, so you don't have to....... Look and Learn.....👍🤔

[@paulmccoy2908]

It’s easier to understand the design reasoning when you look at it like a universal constant-current power supply with very basic communication . Though it is marketed as 20v/40v it’s likely that the charger is still capable of charging most any Li pack voltage from 3s to 6s. You’ll notice that the power specification on the bottom probably doesn’t even list an output voltage. The unit is also designed to operate in a “waiting for battery” mode for months or years as many people never unplug it between charges. The circuitry is very similar to the DeWalt Ni-Cd chargers from the turn of the century. I still collect those chargers whenever I see them because they can very easily be modified to charge almost any battery voltage of any chemistry as the default mode is to simply pump 3 amps at 90% duty cycle into the pack for a timed duration, then charge to a voltage threshold that is calculated from there. I make a simple voltage divider to satisfy the thermistor input and the ASIC is none the wiser.

[@user-gx6jb6wc5g]

In this case the standby voltage is around 15V, and the data communication suggests this charger is specific to one battery.

[@teardowndan5364]

While the bulk output bypass capacitors may be a very common failure point, the auxiliary power capacitors are pretty common failures too since they are much smaller than the bulk capacitors which makes them that much more susceptible to the nasty switching transients in a flyback circuit. When the output caps have gone bad, the auxiliary cap are almost certainly bad too since they are eating more of the same transients the bulk capacitors aren't able to take anymore. My DSL modem started acting up a few months ago and the only problem I found is a bad auxiliary cap in its power brick.

[@keithking1985]

Looking forward to this 👍💚🇮🇪🙏🏼

[@charles2411-i8f]

Fascinating. I use a Ryobi 18 volt system for a very old flashlights around the yard pruning trimming cutting firewood. Anyway I recently bought new lithium cells that have a 3-year warranty and it lasted one battery lasted me a little over a year which makes me think I don't want to buy a car with lithium batteries. So maybe one of these new battery technologies using carbon might be more fitting for my electric car???

[@user-gx6jb6wc5g]

If your Ryobi battery stopped taking a charge it may have been accidentally stored discharged for too long. They are prone to locking out, and can often be recovered by bringing any cell under 3V back up to 3V again at very low current. But it does require a good understanding of lithium battery safety.

[@-Jethro-]

@@user-gx6jb6wc5gI’ve had several Ryobi batteries do this and was able to recover them, but it requires disassembling them. Too bad they don’t bring out all of the inter-cell voltages like Dewalt does.

[@kimchristensen2175]

I wouldn't let the Ryobi experience put you off getting an electric car. Just don't buy a car made by Ryobi or one of it's affiliates.

[@jamesbrewer3020]

Asa always great job.

[@erlendse]

Suprisingly simple actually. the "microcontroller" aka the thing controls the feedback. And each half-battery can be switched out to allow the battery controller to do balancing. Diodes allow paralell charging if desired. It's unclear if the battery commands the charger, or the charger does the thresholds e.t.c. itself. I would guess charge is moving between the cells or both at same time in order to give a consistent state if the battery is removed early! Not sure if the battery is allowed to balance before the charger indicate all done. Like the mains supply can keep the electronics going without charging the battery itself, potentially doing some top-off while balancing. No need for a supply driving two buck/boost converters with controls for each half. Like the build would take way more parts!

[@snfn7847]

Very interesting, many thanks bud

[@smalcolmbrown]

Thanks :)

[@ejonesss]

i have heard that you should charge all the cells to the same voltage before paralleling them otherwise there will be a rush of current as they try to balance. if the 20/40 volt batteries does some series/parallel switching then what happens if you discharge partly using the 40 volt tool then since the battery will be out of balance then you put the battery on a 20 volt tool there would be a rush of current between the batteries. it could be possible that why tool batteries use 2a or 2000ma cells is because with the load they could sag as they try to balance and at such low capacity there isnt enough capacity to cause problems

[@user-gx6jb6wc5g]

The batteries should always be fairly close in voltage due to the way they're used. Series for 40V and parallel for 20V.

[@johnsenchak1428]

Real nice video. That voltage divider on the third page could be a under voltage lockout . On the fourth page that could be a over voltage and temp lock out That output of the MCU go to the controller and then shuts down the circuit through the opt-coupler

[@user-gx6jb6wc5g]

The battery itself removes the thermistor signal for under voltage.

[@3dlabs99]

Designer: "Ok product is ready for review" Reviewer: "You used clips... BigClive will have a bad time when he takes it apart. We want him to have a good time. Can we make it come apart easily with just 4 screws for the same cost?"

[@markiangooley]

I think that Aldi in Britain is Aldi South, just like Aldi here in the USA. We don’t get as much interesting stuff here, though, whether food or tat or electronics or tools. I keep seeing reviews by Brits of Aldi televisions but I can’t recall having seen a television for sale here. Small kitchen appliances are far more usual than tools.

[@BedsitBob]

I'm wondering if the Active Energy batteries will work on the Parkside (ie. Lidl) cordless power tools? I know the Parkside tools only have three terminals (instead of the five as on the Ferrex ones) but, AFAIK, the Parkside tools all operate at 20v, so maybe the three terminals would match up with the 20v terminals, on the Active Energy batteries.

[@rpavlik1]

That is fascinating, impressive job reverse engineering. Lot more successful than my attempt to reverse engineer and repair an old (multi chemistry multi voltage) Craftsman C3 tool battery charger, though I could at least find data sheets for the parts.

[@robert574]

Clive, I was extremely impressed with this video 👍👍👍👍. That's the most thumbs up I have ever given a video from anyone. I'm already subscribed, but I almost feel like I should unsubscribe and resubscribe again.

[@justme5384]

The live and neutral only has a difference in the UK since we use unpolarized plugs everywhere else.

[@kimbledunster]

How many rough draft schematics do you go through until you get a good layout on the page?

[@user-gx6jb6wc5g]

Usually just one initial rough one.

[@kimbledunster]

@bigclivedotcom Wow! When I do that sort of thing, there's paper everywhere. Thanks for all your videos.

[@Mike_5]

These chargers possibly include special circuitry to prevent you attempting to charge a Lidl Parkside battery in them as that would not be Cricket

[@notsonominal]

.. that was, uhm , comprehensive!

[@slugrag]

Always wondered if these were any good. I remember for months whenever I went in Aldi, they had many different tools, but not a single battery!

[@user-gx6jb6wc5g]

I think a lot of people were buying the cheap battery packs to strip the 18650 cells from.

[@reacey]

2:13...thumbs right next to the main filter cap .. tut

[@k4be.]

The microcontroller possibly has 2 operational amplifiers (open collector output so they both drive the optocoupler) inside it, with one input of each fed by some integrated DAC. In this case, the RC networks are for compensation so the circuit is stable. See the amplifier circuitry (pins 1, 2, 3, 15, 16) of TL494. Seems that the IC is made for this exact application: switching power supply with actively limited current. Fortunately, such charger is not used very often. I say that, because the yellow glue tend to degrade when exposed to heat, eventually becoming conductive, and visually almost undistinguishable from remains of a leaking capacitor.

[@erlendse]

the only part that confuse me there is: it it looks like positive feedback to me, and that does no good for stability.

[@user-gx6jb6wc5g]

I wondered if the slight positive feedback was for hysteresis reasons to give a slight schmitt trigger effect.

[@erlendse]

@@user-gx6jb6wc5g Probably more like feed-forward. But then it doesn't seem to be something that needs to respond quickly. Turn on LED to slow down supply is the usual way.

[@k4be.]

The feedback appears negative for me. If, for example, the output voltage goes higher, the IC pulls the optocoupler lower, and this causes the voltage divider output to go lower too via that RC circuit.

[@gopiramki3783]

@bigclivedotcom The IC looks like rebranded HT45F5Q-2 from holtek. I have designed e-cycle chargers based on this MCU. It is a special purpose microcontroller designed for charger applications with DAC and error amplifiers built in.

[@royspeakman1157]

I was very curious about this myself ?

[@norcal715]

The "bootstrap" capacitor is another high failure item, especially if left plugged in for decades. When it has to restart then it relies on the bootstrap capacitor to get it started again.

[@ForTheBirbs]

Wow. What a lot of work in reverse engineering!

[@Leroys_Stuff]

Wow way to break this down

[@Erik_Swiger]

Hey, Clive, I've got a question. Do you know of any mechanical analogs of electronic circuits? I wonder if circuits can be replicated as physical mechanisms.

[@kjdude8765]

It's your lucky day. Steve Mould has a whole video on the topic.

[@kjdude8765]

Video Link: kzbin.info/www/bejne/h6POmn2QgK-Zprs

[@Mizai]

very interesting

[@michaelbrophy]

Clive - off topic comment. Have you ever inveatigated plug in energy monitors? I got a pair of these Besvic power meters from Amazon last month. Used one on the kettle and one in the home office for last cpl months. It might be a coincidence but my energy bill has shown a doubling of KWH versus same period last year. I cant see any other reason for a 1000kwh increase!

[@michaelwebber4033]

That looks a lot simpler than the Dewalt charger I opened a few weeks ago

[@ElTelBaby]

1 thing I note is the charger is rated at 4A & the battery is 5A Does that extra 1A stress the charger...?

[@user-gx6jb6wc5g]

The charger can set the maximum current it will put out.

[@ElTelBaby]

@@user-gx6jb6wc5g Been pondering this for over a week now... ? Is the battery only then charged to 4A

[@tvelektron]

Well, the system (i.e. charger and battery) looks okay for me but in fact it seams it does not do any cell balancing at all. So maybe it would be a good idea to open the battery pack once a year to do it maually.

[@tactileslut]

If it's worth doing then it's more fun to design a tool to do it for you. We'll probably find it more rewarding if not economical to hack in a balancer than to buy a third battery.

[@user-gx6jb6wc5g]

If a battery starts giving noticeably lower run time then manual balancing is definitely an option worth exploring.

[@GazVDS]

Hello Yessir! (A little Manx for you!) Great vid, not that I understand much of it, or of the other videos you produce. I still enjoy watching them. I have a Parkside li ion battery charger which has stopped working and would like to donate it to you for disassembly and explorative purposes if its of any interest to you. Parkside are the brand sold by Lidl. Perhaps you could compare the Aldi one to it?

[@user-gx6jb6wc5g]

I have a Parkside charger and batteries here. I should really take a look at them.