Inside a common eBay lithium cell charger - with schematic
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- เผยแพร่เมื่อ 29 พ.ย. 2020
- Unlike the very shady 120/230V units, this one is pretty good. Nicely made and logical circuitry that has an element of hackability to it for fine tuning to your requirements.
The current setting resistor could be changed to tweak the charge current, noting that higher current will potentially result in thermal self regulation of the charge chip. Use of higher current will also make the charger less suitable for smaller cells. Conversely, you could lower the current to 200mA for softer charging of any size of cell.
The LED resistor could be changed to something in the region of 470 ohm to make the LEDs more visible.
Unlike some other charger which fire springs in random directions and require Rubik's-cube grade reassembly skills, this one is easy to take apart and reassemble.
Here's a generic eBay search link:-
www.ebay.com/sch/i.html?_from...
Target cost around $4 shipped.
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.com/coffee.htm
This also keeps the channel independent of TH-cam's advertising algorithms allowing it to be a bit more dangerous and naughty. - วิทยาศาสตร์และเทคโนโลยี
Adding "Homefire" batteries to my list of reasons to buy a label printer
I have a couple of them for like 10 years they are very useful
What's the connection between these batteries and a label printer? I think I've lost the point 😅
@@88Timur88Bahmudov88 Take a look at the thumbnail for this video.
Just use a regular printer and self adhesive paper.
Had a good laugh from HOMEFIRE brand "20k" mAh cells, cheers Clive 😄
That made me laugh too
Meanwhile UltraFire and other worst 18650s
*Giant fake capacity intensifies*
I must be getting behind the times. The highest fake 18650 rating I've seen is 9000 mAh.
10,000mAh of actual charge plus 10,000mAh of actual fire.
“20000mAh” is brand name, not capacity.
A lithium battery named homefire is hilarious
Looks like a printout from a labelmaker, the actual heatshrink is red. Anyway, the _“-fire”_ brands are indeed getting ridiculous.
Trustfire are the wraps I'm familiar with. Dangerously misrated wraps that probably caused a LOT of damage.
ULTRAFIRE
well, it promises something it could easily deliver!
I have a Chinese spark plug called 'Boil'
I live for hearing the famous "One moment please"
The same phrase you hear from the answering machine when you ring up customer services for a Scottish based energy company Scottish Power.
action-packed phrase
Scottish Power moment: Nothing happens for 20 mins
BigClive moment: More interesting stuff delivered instantly
I have the 2x version of this. It's the same circuit twice, for anyone wondering.
That’s a nice obvious way of doing it, better than just putting cells in parallel.
"We didn't start the fire, it was always burning, since the world's been turning..."
i Like how you work. your explanation are very deyailed. no silly music. I feel like i am in class. keep up the great works
Much better design than the one I opened up and all I found was ..... a resistor. 🤝
You'll know when the battery is charged by the lithium venting.
@@JasonW. I laughed at that way more than I should. 😄
Hey, at least it *has* a resistor and not just a really thin cable doing the same thing.
@@aprilkolwey4779 Wire? You mean a high tech Tesla cell fuse, right? 😁
First thing I saw as I picked up my tablet was the notification of this video. That reminded me that I had a couple of 18650 cells on charge and I was not certain of their reliability. A quick voltage check suggests one of them is definitely a bit dodgy, I'm glad this video reminded me to take them off charge.
In actual fact, the charger is a modified flip pin charger, pins removed because I didn't want to plug into a death adapter and a flex and UK plug substituted. The open circuit voltage is a reassuring 4.2v and although I couldn't check the transformer itself, everything else seems pretty well constructed so maybe they aren't all dangerous crap. Twin charger with separate control on each circuit.
I like these low component-count designs much more than the old mains-powered ones with a dozen components. Less chances for the manufacturer to use substandard parts, on top of lower shock risk.
4:18 - "One moment please.." 🙂
The original worklights on my boss's Huawei mini wheel loader are called "Arson".
I was talking to a friend on the phone a couple weeks ago when he got a message: his house was on fire.
He left a cheap 20AH 48V LiPo battery for his boat on a charger, outside. First the boat caught on fire, then the house. Total loss.
Play safe everybody.
Lmao i clicked the video bc the battery said HOMEFIRE LMAOOOO
You know it's still 2020 when Clive actually recommends something bought from eBay as a good product.
Clive has recommended stuff from Ebay in the past, like head torches, resulting in them selling dozens and dozens more after the video dropped. So that's not _that_ unusual.
1:35 You are a very brave man, grabbing that dubious quality charger in a way that makes contact with one of the conductors.
My guess is that BigClive knows *EXACTLY* what is in that yellow USB power supply between him and mains.
Love the thumbnail - “keep the homefires burning”?
One of ours cats was absolutely fascinated with the pcb study section, maybe we can add your channel to his list of TH-cam birdie TV for cats 🐈
I apparently have a huge cat following.
I like the LED circuit. I will store that configuration in my circuit tool bag.
Excellent tear down and explaining it's components innards .
UltraFire: Meh
TrustFire: Hmmm
*HOMEFIRE* : Wtf?
Ultrofite exists, found one in my country
@@bluestone-gamingbg3498 Fake UltraFire: SuPer HiGh cApAcItY (9900 or more)
Weight: Suuuuper light, even AAA battery still has weight than it.
Note: I dissasemble that battery, and the content is SMOL.
Guaranteed fire
@@agustinusreynaldi7101 the largest 18650 Cell ever produced is 3600mah...
How about a more comforting name like NOFIRE
Took a few times of looking up the data sheet, but I now do finally recognize the LTH7 IC silkscreen, since it's in nearly all my cheap self charging electronics.
Datasheet here www.analog.com/media/en/technical-documentation/data-sheets/405442xf.pdf
Brilliant. I have the same charger but in a dual cell version and I started to question the reliability of them. You've put my mind at ease. It seems to be able to also charge the 3.2V LiFe 14500 cells and it knows to stop at 3.65V despite its 4.20V charging output. So more intelligent than I thought. Mine is a 1000mAH output version though. However, that could just be 500mAH per cell since it's a dual cell charger. I think they addressed the LED brightness in the updated versions as now they are plenty bright enough. I have a Green LED for full charged and Red for Charging status.
Might be a cheap and easy way to integrate swappable Li-ion cell(s) into a project?
Great video Clive.
Mr. Clive you should totally make more trash kitchen videos. Love your videos btw
Considering some of the cheap chargers that've shown up on this channel, I was seriously worried that thing was just going to put the 5 volts from the USB right across the battery, with maybe a token-gesture resistor. I was pleasantly surprised that it's got proper, relatively sensible circuitry inside.
Did you know, Clive, that Argos now sell singular Molicel P26A 18650s in plastic tubes? They’re in the _”fogstick”_ section. Really excellent high-drain cells with 2600mAh capacity and a stated CDR of 25 amps. I wouldn’t give them a load of over 20, though, for heat reasons in a high-drain application, but they’re very respectable cells overall.
You should be a Chinese Cheap Product Checker - you find so many cool features to point out (like better position of the capacitor / led resistor value)
"ONE MOMENT PLEASE" Indeed lolol
Time for a project Clive 😊 been waiting for one for a while now...
It's fairly ironic that looking as something qualified as "a textbook design... actually pretty good" becomes a welcome surprise when looking at low-cost end-consumer electronics.
this chip is actually LTC4054 made by Linear Technology, so it has maximum charging current at about 500mA, and does have thermal limiting.
Where can we get these homefire brand batteries?
I think RapidFire makes em 😂
Cheapo store
Fleabay, big rock candy mountain (china).
I searched for homefire on AliExpress and there were a lot of search results.
You could get them at one store, but it burned down
Those are equal parts clever and infuriating in their mechanical design. I'm not quite sure why I have such an aversion to that sliding contact, but it is very clever.
Because you've had the infuriating experience of trapping your fingers in them in a past life, maybe?
@@penfold7800 I think it's more that they often make very poor contact.
@@penfold7800 instructions unclear, dick stuck in battery charger...
Always awesome vids love a hug off him 😉
I've got a similar looking one that plus into the mains (Type A). It has the helpful label on the front that reads "Intelligence can be positive and negat I've charge quick charge, Safe and reliable". It lets me know at a glance it wasn't manufactured anywhere in the western world. I haven't taken it to bits yet, but I probably should before I do something silly like plug it into the wall.
Waiting for the "Uncontrolled Fire" brand cells.
I see your "Uncontrolled Fire" and throw down a "Firestorm".
Don't make me use my "Hiroshima"!
Dreamfire.
- HOMEFIRE? Shut up and take my money!!! XD
Pretty happy with my Liitokala Engineer Li-500 charger. It analyzes true capacity on the discharge cycle. So, you can find out that those HOMEFIRES are actually only about 2000 mAh (or less!).
Nice. I recently bought a 4 cell USB powered charger. Each battery charged independently. Springed contacts so will do 18650 & smaller.
Hi bigclive i would have been interesting seeing you improve the LED as you say if can be done. Because i oneday want to start to building some things so i learn from you myself.
A charger with a strain gage ! That seems like rather bold strategy. ;)
I ordered a few of those the other day, gonna gut it and use it as an adapter for my proper charger that sadly can't fit protected cells.
As always, very informative and that, but I was kinda hoping it would catch fire as soon as it was connected 😂
You're braver than I. I wanted to look into replacing li-ion cells myself, but after one that I removed hissed at me I'm leaving it to the pros. Unfortunately even places like Batteries + won't touch them.
Mine used to do that too but now i have learned to charge and discharge them at no more than C/10. Had no problems at all since then - even charge them on my bench supply (set for 4.2v per cell).
Ok you NEED to get some merch made with a image of a HomeFire battery on it..
The battery is from the future....😱
I have a few similar to this only they plug directly into a wall socket via a 2 prong plug. I don't know weather it was the type of battery I used or what but one of them blew up when I switched it on to charge, after that I never used them again and bought a proper li-ion charger.
Thanks clive
I have a very similar charger that came with a flashlight to charge the 26650 battery and it seems to work just fine for the two different batteries I charge with it and I've been using it over 2 years with no issues. It will typically charge a battery up in about 2-2.5 hours depending on how much I drain them. I just plug it in an old USB phone charger and won't plug it into a computer.
They could put 2 or 3 2.2k resistors in parallel and still keep the same pick and place BOM,,, but that would cost a micro cent more!
With only 2 resistors per unit and only six different component types (if I counted right), adding a seventh reel is probably cheaper than adding a third resistor.
They don't get much simpler...cheers.
Would live to see this modded for brighter LEDs and 1A charge current.
I was expecting one of those blue pcb battery charger that you can buy from electronic sellers online
they're commonly using the tp4056 chip which IMHO is somewhat better because of up to 1A charge current possible, so I guess this one must be cheaper. On the other hand here you get the 18650 holder as well, not just the PCB, so in terms of DIY this charger is probably a better purchase.
When you take a picture to show to us is it on photo paper because it seems pretty clear
Thanks for the overview - though I'd rather stick to my Nitecore d2, Nitecore i4, XTAR VC4 and Turnigy Accucel 6. :)
Clive, video idea: how charging is handled in devices that are in use. I've been trying to figure out how that's done properly and having a devil of a time finding good resources.
The simplest method that comes to mind which isn't garbage, the charger supplies constant current to the battery terminals until a max voltage is reached, then shuts down until the voltage drops to a restart level. Actual charge rate is reduced by the device load. Depending on device current draw, a modest time delay between charge shutdown and restart may need to be enforced.
I bought a couple of similar chargers and I had to take them apart and bypass the spring with a wire. Otherwise the spring has too much resistance and results in the charging cut off at less than 4.1v. After the bypass the happily charges up to 4.17v and I've been using them for a couple of months without issue.
I was having a hard time finding the part with the homefire battery because of the comments but then I realized it was the thumbnail..
you should have a box of those little USB to mini cables around. Generally reliable or sometimes dodgy? I use OEM if possible but sometimes..
That's is a great charger the yellow one you use you got it i guessing from poundshop for 2£ it is great
I'm now getting wine ads on Clive's videos. Sadly with a lack of carbonation.
"Keep the homefires burning..."
I see the thunbnail, I like
I hear the Thun-butt say, I dis-like
Hello big Clive I have learnt a lot from you
Hi sir, great video, knowledgeable, sir any video of reverse engineering on Nrf24l01 or 433 MHz RF transmitter receiver module circuit diagram, explaining everything ie. Components used and working of the circuit diagram
Ah, this is quite receptive, able to accept a wide variety of lengths and diameters. Beauty is in the mind of the beholder! Tee hee;)
The application note states the Earth Pad needs to be a large copper area for best thermal performance. Also the pin that is being used to switch the LEDs is limited to 10mA. Also note this pin is in fact a tri-state pin indicating 3 different states of the charging circuit. See the application note for details.
if the current setting resistor values give the same charging currents as in the 8 pin version of the chip, 1.2k is what you often find in power banks, which gives a charge current of 1A. 1.5k would give you about 750mA. 1k would give 1.2A, which is probably a bit too high.
the formula is I = 1/R x 1200
I've heard that homefire cell is very good for cold places, like, you know Isle of man in the winter
Have you done a video on the cheap, fold-out wall plug ones so I can worry? I was just charging an 18650 in one of those about 1/2 hour ago and it just seemed kind of sketchy to me. Really, Homefire? What great marketing.
I ripped out all the electronics out of the mains version of this charger and put in a TP4056 charging board. The original electronics is dangerous and would overcharge the battery.
Nice catch, great save. 8)
@@wojtek-33 the mains powered version I had didn't have any chip. That's tje one I put in it.
I have decided I really like the 3 AAA flashlights because in a pinch you can cut any usb lead and put positive to one end of the pack negative to the other and you have a crappy nimh charger.
That's not regulated. Unless you're talking about powering a mobile phone (where its own power input and battery would regulate power) it wouldn't work very well. You could trim one of the led outputs and use that to charge, but it would take a long time!
I'd like to see the difference between one of these and say the LiitoKala or Nitecore chargers.
Nice video, thank you! Will the charger shut off on its own?
Yes.
Nice. At least looking from phone's screen it looks like slider has been stolen from generic office stapler 🙂👍
Remember when we used to just plug a thing into the wall? Now we gotta plug a thing into the thing we need to plug into the other thing we plug into the wall.
Whaha omg the home fire battery lives up to its name when you leave your home wile charging 🤣
Should take a look at an xtar vc4 or vc4s charger does NiMH, NiCd and Lithium ion batteries at the same time
Probably costs more than 3 quid, though.
@@RedwoodRhiadra £16 but is a lot more useful. The vc4 is the normal charger, the v4s does a full discharge charge cycle with capacity testing along with being just a charger
How about a quick one where you change that resistor and make it brighter? Actually, I am wondering if that will have an impact on the chip itself.
Just solder another resistor, of the same value, onto the top of the original resistor. It will rob the charge current of a few mA's.
I got an 18650 once that was branded “Ultrafire” it still scares me to this day ever time I charge it... I don’t fancy burning my house down 🤣🤣
People always talk about those being so bad but I've had two of them for a decade in a headlamp with no problems.
@@johnpossum556 I got them with a torch. Did you notice the spelling error on them battery too?
@@BlitzdUK They charge in the headlamp so I never usually see the names. None that I can tell except rhe usual 3oooma rating which I suspect is about 300% more than what they are capable of. Apparently as long as you don't try to run them like high discharge power tool batteries they are just fine. The headlamp has a cree XML6 so that gives you an idea of their true load and I rarely run them more than about 20 minutes which is about how long it takes me to bike from downtown to my home.
The real problem with those cells is that they’re rewaps from other companies with massively inflated capacities and CDRs. It becomes a huge problem in a high-drain application like an electronic cigarette, because it might state that it has a CDR of 25 amps, but actually can only safely handle a 10 amp maximum draw. Put two of those in a series device and give it 70 watts, it’ll hit over 12. Wrap says that’s well below unsafe levels, science says expect thermal runaway in the not-to-distant future.
If you can find them cheap enough they would be good for Home Brew cell charger dischargers using the spring cell contacts / terminals. Say a dozen or more.
I like how simple this is. What is the common failure mode of this chip though? Could it potentially overcharge the battery? I try to never leave lithium batteries unattended while charging, however i do forget some times and leave my flashlight battery plugged in at night. I do try to keep it clear of anything combustible, just incase. I also use protected cells. But redundancy is never a bad thing when it comes to safety.
Redundancy is always good. I'm not sure what the failure mode of this chip is. Going short circuit is possible. That's where protected cells have an advantage.
@@bigclivedotcom Interestingly this prompted me to take a look inside my 2 instances of this charger. They do have Red and Green, Charge and Charged led's but also an A1sHB p-chan Mosfet on the output of the LTH7 charge controller, Ground and Positive O/P.....
It's a charge chip so at least it will cutoff but based on the price I'd rather just buy TP4056 and basket, then stick it to the basket. Or if you're more manual and can do UV circuit in any soft based on preferences then you could buy nice SMD 18650 holder and make own board which holds TP4056 and rest of needed components . Anyway... I have tested a lot of TP4056 and even if they're cheap they won't damage battery at all, can be "programmed" from 100mA to 1A via resistors plus TP4056 has high frequency, small current trickle charge for cells that went down below 2.75V(typically liion or Lipo should be discharged to 3V max though but most normal manufacturers references 2.5V discharge voltage for quality cells and there is nothing bad when they drop to that value).
I got a very similar looking charger some time back. I stopped using it because it got suspiciously warm and didn't appear to stop charging at 4.20v. If I still have it and find it I should send it to you.
Same, mine actually started to melt!
Got a similar one a couple of years back that plugged into mains. The contacts started glowing red hot as soon as I plugged it in so I tossed it...
The chips are very cheap. JLC can fit an equivalent (4054) on a board for about $0.025 each (plus $3.00 to load the tape)
Lookat the cutout above his left hand at 5:27. Looks hand made.
Go on then Clive... Change it for a 1k and get the heat measuring kit out... Is it a worthy replacement or will it just go pop?
Hi Clive. I have some 26650 ultrafire batteries from my touch. Can you recommend a good charger?
Had a "homefire" branded 18650 make a pretty impressive bang recently while charging. Shot hot black debris all over the carpet and filled the room with smoke that would be useful for riot dispersal... Saying "Never again." would be redundant.
Did you over charge it.
@@simontay4851 Most likely scenario. May have also missed a ding in the cell. The charger is still fine. Shuts off at 3.8ish The cell is pretty far beyond reconstruction. The whole thing was less than confidence inspiring... I dislike mysteries
eBay has apparently banned bare 18650s on the site. Best I can find they have not liked the sale of 18650s for a while now and LG Chem pressured them to ban the sale of bare cells back in August 2020. I would love to be proven wrong here but as far as I can tell (in the US at least) there are only a handful of listings for cells remaining and it seems that they are preventing the listings from being reposted when they expire instead of going around and trying to pull the existing listings down.
How would one of these handle a cell that has been deeply discharged? I've seen sophisticated chargers that will refuse to put any juice into a battery if it's voltage is too low. I have a SkyRC MC3000 which is one of the most sophisticated chargers for cylindrical cells, and sometimes I have to parallel a charged battery to "bootstrap" the charge.
Great, I got the exact same in a package with a torch and 8 LiPo 18650 Batteries with 3Ah plus USB-C Cable for 20€
not gonna lie, clicked for homefire
It looks like it has a similar layout to my charger for my e-cigarette but recently snapped the plastic off and broke the wires I had a charger for one of those e-cigs at called blue it's polarity was reversed from the all the other normal chargers and it's a wee bit more complicated
Have you tried the eBay flame fx bulb?
Not sure I like the charging current being passed through the spring, be interesting to see how much voltage that drops under full charging current.
Yeah, thinking the same here.