@@Chuckiele I think if a product kills more than 10,000 chinese mothers assembling these units in their spare time at home, their government makes them prove that they've made the product 10% +- 1% better before they're allowed to re-market/re-brand the design again.
I noticed that there are 2 vertical slots at the "top" of the charger that look like they might accommodate 2 prongs that would allow the "charger" to be plugged into main (eek!) power.
I once made one of these with an even cheaper construction, using a thinner cable... as the resistor. Yup, USB port straight to the batteries through a thinnish cable.
It is a nice case, and I'm amused that there's a legend molded into the back reading "AC/DC adapter" and some specifications. Apparently repurposed from something else.
How about this one, Clive. A few weeks back I was diagnosing an issue with a 14 kw Generac standby generator that runs off of natural gas. I removed the battery from the unit and attempted to start it, in which case the 12 volt automotive battery EXPLODED at my feet. Turns out the charger was putting out 20.7 volts and cooked most of the acid out of the battery, leaving some nice hydrogen behind that ignited when the load was placed on the battery. How I am unscathed truthfully amazes me. Generac will be replacing the battery and charger free of charge as a result but will not be replacing my shoes or pants, which were damaged by the remaining battery acid that sprayed out. For those first few seconds after detonation, I was almost sure that I was blinded. When I regained sight I was shocked. I have photos of the aftermath if you care to see...
That sounds a scary incident. I can attest to the destruction of clothing when you get sprayed with battery acid. I had a favourite pair of Yakka work shorts that were destroyed in the same way.
@@bigclivedotcom Yes, it was scary. Losing eyesight is a very big scare for me. Can't say I have ever had something so big and violent explode at the tippy tips of my feet. I'll never be so casual about batteries every again to be honest, whenever working around them, eye protection will be a must for me.
Love watching your charger videos. My worst case one was for a cordless drill that cost nearly £100. The charger had a transformer, a bridge rectifier and current limiting resistor that caught fire the second time I used the charger!
As with so many successful ventures, in time , pop up a myriad of imitations. Your channel is still the most accurately informative and you occasionally blow things up too. Keep up the good work BigClive.
Clive! I bought a drone from China a few months back and it's brilliant, however... The charger than came with it made my LiPo swell on the very first time using it, and a few google searches suggest it's quite a dodgy charger. How can I send you this and assist on your quest for the shittiest charger???
Yes, air, makes up the vast majority of the volume in that casing. That goes some way to explaining that extraordinarily large USB plug and even then there's bugger all in that too.
er...i have actually done that...sort of... charging batteries from mains through a 40w filament bulb, feeding a bridge rectifier feeding the battery.. 😱😉 works but very power inefficient, but not so bad if charging lots of batteries in series....
8:32 Is it just my imagination, or are the two rectangular holes / slots on the raised top-side of that case, eerily similar to what might fit into a US mains socket? They're a bit offset to one side, though...
I remember years ago opening up a mains charger for a hand held amateur radio transceiver. The battery pack was NiCd and cost something ridiculous. There were several types of charger. The basic version had a 2.5mm plug, one small transformer, one diode and *nothing else*. That was the official charger too.
That circuit in the plug is also commonly found in the chargers for toy grade drones. Most of the lithium batteries for these toys include an integrated protection circuit, so all you need to charge them off of usb is a resistor to limit the current.
I have a couple Sony NiMH chargers that are an excellent design. They can charge single cells and shut off at full charge. I scarf them up at garage sales. Batteries last ten years. They're universal voltage which is nice when I visit Big Clive country. I have a Kodak "Value Charger" that came with my camera, which consists of a 60 Hz 120V transformer, diode, and 4 resistors. I think that ties for cheapness with your USB one.
2:32 I know it was a throwaway comment, but two things about Kingston computer locks. First, they're _very_ effective at stopping a form of theft that's common at office buildings and college campuses. A thief visits an building around lunchtime, dressed to blend in. The thief looks for an unattended laptop, picks it up, and walks out as if they own it or they work for IT. At some locations, thieves can easily take $10 k of equipment in a single lunch break-not including the lost data or downtime. Second, they're actually often quite a lot stronger than they seem, depending on the chassis design. They certainly won't stop a dedicated adversary with resources and skill, but they'll stop most common thieves, who are typically looking for easy targets. Security should always be evaluated in terms of threat profiles.
Not sure if anything has changed but your lighting seems a tad more yellow than usual and it's harder to see smaller details. The inside of the charger itself was quite hard to make out for me personally.
Regarding the unpopulated LED, your schematic and explanation are both incorrect. The unpopulated resistor is in parallel with the red LED and its resistor, and the unpopulated LED is in parallel with the transistor (collector and emitter). So the "green" LED would only be on when the transistor is off.
Functionally, a diode would have made sense, to indicate (roughly) the charge status. In practice, there would probably be a pretty large overlap where both LEDs stay partially lit, which may be why they omitted the second one.
The claim was in parallel with the *existing* LED and its resistor. The unpopulated resistor is of course also in series with the *unpopulated* LED, but that's not what was being referred to. Annotated board: i.imgur.com/VEbwXzI.png Corrected version of Clive's schematic: i.imgur.com/WVm92L1.png
The slot on the back is for an outlet plug. I've seen battery charger that plug directly into the wall and hang flush. I think that is a double duty case. Not 100% it just looks that way.
Does that 1.5 volts max value on the batteries change as they corrode inside? If the permanent logic on that power circuit design has no way of checking the new max voltage of the cell(s), then it seems overcharging is pretty much guaranteed by this device on all but the newest of cells.
The cable used on yours is normally found in cheap products and they all have different end connectors. I have a cheap rc car and it has the exact same cable but it has a connector at the end to charge the battery. They normally have red leds in it to indicate the charge. Usb and cable are always the same on all different types of that cable.
I thought the same thing about those Kensington lock slots I had an old laptop and a lock at work and I tried as hard as I could to get it off without tools... kicking it hanging from it, I totally destroyed the laptop and even made a few marks on the desk but the thing never did come free... They are a lot stronger than they look.
I don't get one thing: you can only use it to charge 3 cells at the same time? What if I want to charge only one? Would the charger try to push that only cell to 4,5V or would it not work at all?
On the plus side yours comes with 4 real screws. I got one (bundled in with other stuff) that takes all the round lithium ion single cells and they used 2 screws and molded the other 2 screws and holes for them into the plastic. I suppose it saves a penny every ten chargers.
I bought one recently for $1.25 Australian minus 50% because the place was going out of business and I think it might give even this one a run for its money
Why do you keep discovering working LEDs within completely opaque casings? Or was there a hole in this casing allowing you to see this one this time? *edit - oh at 5:43 you mention that, sorry, ignore me.
i bought a pack of those cheap usb lights, three LED chips and no on/off switch. (uxwbill used one in his "looking for fake solar cells" video recently) i was planning to use it with these small power banks but it's not working with one power bank. it will just dimly flash every half second, and if i charge the power bank just a minute it'll work again, and the lights work fine with my other power banks or in the computer usb port so i'm thinking it's a faulty powerbank. it's brand new so i'm looking for any thoughts?
I can't help but think Clive's symbol (maybe the universal symbol?) for LED's on schematics looks like a :3 face with longer eyes (=3). Kinda cute IMO.
I bought a really expensive charger when I lived in Norway. It had charging indicator lights. The only thing it does is to shine green when a battery is connected. In a way that is a indicator of nothing.
If I can find it, I might have a present for you. The shittiest battery charger I've ever come across, for 18650 cells. I used it only once, because it charged my battery to something like 4.7 volts. It was _extremely_ hot when I unplugged it, though the battery wasn't bulging yet. Probably would have exploded if I let it go any longer. Came free with a $8 LED flashlight from eBay. I should have known better.
We once got a led torch from ebay- came with a sort of ok mains charger, but the 12v car charger literaly just used a resistor to "limit the current" to the 4.2v max li -ion cell I discovered it becuse when i used it i could smell the resistor burning and melting the plastic housing!!
I wouldn't put any guarantees on the transistor surviving if the batteries are really flat or short circuit. All the current will go through the B-E junction up to the current limit of the USB power source less than about 150ma for the resistor.
andy fletcher Yes I was thinking the same, seems quite an odd arrangement, even if the current is limited by the USB port. Wonder if its a special transistor to be able to handle that - perhaps with an embedded base resistor like someone else has suggested
I would like to see a resistor in series with the base lead of the transistor. Otherwise, if a high current USB charger is used, the base-emitter junction of the transistor could be blown.
I think the circuit would need a resistor in series with the base of the transistor. Otherwise, when the batteries are completely discharged, on the base there are 5 Volts and a very high current would flow into the base of the transistor.
A family members borrowed my tablet charger and cable and lost it. They replaced it with one from EBAY and when I got it I measured the output and it was live voltage imposed over a 5 volt DC difference of potential. It didn't even have any useful parts for other projects. When I looked inside there was what looked like a Chinese coin taped to the circuit board. I thought "at least I got a coin..". No such luck it was steel slug KO from an electrical box. I think they were using it to prevent rattling, shim?
I never ever had any luck with NiMH batteries. They strike me, from experience, as being NiCd without the 'actually storing electricity' thing. Other than no cadmium, is there actually an advantage over NiCd ? Anyone mentioning memory effect gets a chinese shoe warmer...
TheChipmunk2008 I've had better luck. At least according to the packaging, NiMH supposedly stores more electricity than same size NiCd, but less than Li batteries.
I have one from an old 4 battery charger with no name from China, it charges CR123s. I used them in my old DIY laser. But once while sleepy I stuck one in the charger backward and the thing caught fire. I put unplugged it after put it out and it still works. I mean a battery charger with no reverse polarity safety. Why? It cost very little to add that. :P I still have it. Though the batteries and laser are long gone now.
Those holes on the back look as if one version had the board in the battery case and plugged into a wall outlet and hung from the outlet. I could be wrong.
I'm guessing that slot is for a mounting screw. Although having just one of them makes me wonder if the person that designed the case knows how mounting screws work...
Clive, any reason why they didn't include a diode on the PCB to prevent the batteries from sending voltage back to the USB plug? Does the transistor achieve the same result without the need for the diode?
Current could still flow back through the resistor into the USB port. I'm guessing the reason they didn't use a diode is because it would have imposed an additional 0.7V forward voltage drop on the supply, which would have likely prevented the cells from fully charging.
They could have used a schottky diode at around 0.2V drop, but it would raise the BOM by a cent and then they might have wanted a precision resistor, raising it another cent.
I've bought some 5v usb to 12V DC boost converters...built in the cable on a board like that off eBay...they work pretty well for a dollar....one gives me 12.05 and the other 11.86 consistently....I like them for using a usb battery pack to power my evil mad scientist electrical projects that need 12v to kick off ....only thing that sucks is they are low current so a 12v 1W laser isn't happening even with a control board or TTL
+bigclivedotcom, I'm not sure where I ever read it and can also not verify if it's true, but the Kensington lock (or whatever it's called) was said to be designed in a way that it causes a lot of damage if you actually try to steal a device locked to one of those kind of cables, by either ripping the chassis open at a "tactical" place to render the product completely useless, or make it appear so badly damaged (though maybe still working) that you are unable to sell the stolen goods.
I have a question related not to this video, but am curious nonetheless; do you live on the Isle of Man, or were you just over for TT? I saw the meet up thing you did but must admit I was too much of a fanny to come down. It would be nice to think I might run into you some time if you do live here :)
Those slots on the back of it remind me of what you'd see on the back of an old landline telephone to hang it on the wall. But those look too small to be used for mounting. And they're not really in the best position for it.
Clive, I have a spare wismec predator mod for an electronic E cigarette. It's spare as unfortunately it is faulty. My only conclusion now is it may have dropped and the usb port is broken and the way it detects ohms is not correct for the coils. I have tried taking the board out as I have seen people slide it out but mine won't. I would love you to have the honour of taking it apart and showing the people of your channel how a more advanced e cigarette battery works and how it detects that charge state of the cells. It would be very informative for me too. Can you please get in touch with me or give me a way of getting in touch with you so I can arrange getting this sent to you? Thank you. Gareth
Im blown away they can even turn a profit sellimg at that price, i cant imagine many people buy this workshop rejects perhaps even still after postage how do they do it?
Clive! I have a ALLSTART boostmax 560. It's 6 months out of warranty. Booooo. The jump start portion of the unit works but the outputs for the USB are not. I would like to send it to you for disassembly buddy. Where do I send please 👍👍 thanks mate Carlo
Clive, please do not stop your quest until you find a mains powered one that is just a resistor :)
It would have to be a resistor with a diode at minimum. Otherwise it would never charge! XD
@@Chuckiele I think if a product kills more than 10,000 chinese mothers assembling these units in their spare time at home, their government makes them prove that they've made the product 10% +- 1% better before they're allowed to re-market/re-brand the design again.
or something cheap that kinda just about works as a resistor
The bare minimum charger would be a diode and resistor. The worsr usb charger i ever had only contained 4 components
@@bichela i use my fan heater as a ballast when i am playing with mains stuff
I noticed that there are 2 vertical slots at the "top" of the charger that look like they might accommodate 2 prongs that would allow the "charger" to be plugged into main (eek!) power.
I once made one of these with an even cheaper construction, using a thinner cable... as the resistor. Yup, USB port straight to the batteries through a thinnish cable.
Now that's hard -core cheapness.
Oh, so you're the guy in china making dangerous battery chargers?
Luke Den Hartog Tell me your time travel secrets
What? No fire, no explosion, no blood? What kind of a review is this?
No vomiting either.
No shit either.
Saving it for the holidays, maybe? Definitely easier to explain fire in the winter. ;)
Garth Howe This was a non-Michael Bey edition review.
There was a missed chance of very minor bodily injury at 4:35
It is a nice case, and I'm amused that there's a legend molded into the back reading "AC/DC adapter" and some specifications. Apparently repurposed from something else.
So it wasn't just my imagination - i thought at 8:32 that those slots at the top kinda looked like they might fit some prongs for US mains sockets...
How about this one, Clive. A few weeks back I was diagnosing an issue with a 14 kw Generac standby generator that runs off of natural gas.
I removed the battery from the unit and attempted to start it, in which case the 12 volt automotive battery EXPLODED at my feet.
Turns out the charger was putting out 20.7 volts and cooked most of the acid out of the battery, leaving some nice hydrogen behind that ignited when the load was placed on the battery.
How I am unscathed truthfully amazes me. Generac will be replacing the battery and charger free of charge as a result but will not be replacing my shoes or pants, which were damaged by the remaining battery acid that sprayed out. For those first few seconds after detonation, I was almost sure that I was blinded. When I regained sight I was shocked.
I have photos of the aftermath if you care to see...
That sounds a scary incident. I can attest to the destruction of clothing when you get sprayed with battery acid. I had a favourite pair of Yakka work shorts that were destroyed in the same way.
@@bigclivedotcom Yes, it was scary. Losing eyesight is a very big scare for me. Can't say I have ever had something so big and violent explode at the tippy tips of my feet. I'll never be so casual about batteries every again to be honest, whenever working around them, eye protection will be a must for me.
Love watching your charger videos. My worst case one was for a cordless drill that cost nearly £100. The charger had a transformer, a bridge rectifier and current limiting resistor that caught fire the second time I used the charger!
opening cheap Chinese electronics is like Christmas morning, you don't know what color socks your going to get
I imagine off camera is floor to ceiling Shenzhen dumpster by now. Love the tear downs though
As with so many successful ventures, in time , pop up a myriad of imitations. Your channel is still the most accurately informative and you occasionally blow things up too. Keep up the good work BigClive.
I like how there's the two slots at the back to add pins for a North American wall outlet
Clive!
I bought a drone from China a few months back and it's brilliant, however... The charger than came with it made my LiPo swell on the very first time using it, and a few google searches suggest it's quite a dodgy charger. How can I send you this and assist on your quest for the shittiest charger???
Yes, air, makes up the vast majority of the volume in that casing. That goes some way to explaining that extraordinarily large USB plug and even then there's bugger all in that too.
I'm guessing the next level below this would be a charger that has the batteries wired directly to the mains... :P
twocvbloke nah, just wire it straight to the USB plug with the human hair thickness of wire acting as the resistor.
er...i have actually done that...sort of... charging batteries from mains through a 40w filament bulb, feeding a bridge rectifier feeding the battery.. 😱😉 works but very power inefficient, but not so bad if charging lots of batteries in series....
i also attempted to kick charge into an open circuit sealed lead acid battery from mains through a bulb...it did recover a bit, for a while....
@@andygozzo72 Truly riveting story :D
8:32 Is it just my imagination, or are the two rectangular holes / slots on the raised top-side of that case, eerily similar to what might fit into a US mains socket? They're a bit offset to one side, though...
I remember years ago opening up a mains charger for a hand held amateur radio transceiver. The battery pack was NiCd and cost something ridiculous. There were several types of charger. The basic version had a 2.5mm plug, one small transformer, one diode and *nothing else*. That was the official charger too.
I love Big Clive - he uses the same Poundland tools as me.
He's truly the man of the people.
That's a very good price for 3 solts.
SNAP! “Oh, I’ve snapped it off completely. That’s OK I didn’t like it anyway.” 😂😂😂
That circuit in the plug is also commonly found in the chargers for toy grade drones. Most of the lithium batteries for these toys include an integrated protection circuit, so all you need to charge them off of usb is a resistor to limit the current.
I have a couple Sony NiMH chargers that are an excellent design. They can charge single cells and shut off at full charge. I scarf them up at garage sales. Batteries last ten years. They're universal voltage which is nice when I visit Big Clive country.
I have a Kodak "Value Charger" that came with my camera, which consists of a 60 Hz 120V transformer, diode, and 4 resistors. I think that ties for cheapness with your USB one.
2:32 I know it was a throwaway comment, but two things about Kingston computer locks. First, they're _very_ effective at stopping a form of theft that's common at office buildings and college campuses. A thief visits an building around lunchtime, dressed to blend in. The thief looks for an unattended laptop, picks it up, and walks out as if they own it or they work for IT. At some locations, thieves can easily take $10 k of equipment in a single lunch break-not including the lost data or downtime.
Second, they're actually often quite a lot stronger than they seem, depending on the chassis design. They certainly won't stop a dedicated adversary with resources and skill, but they'll stop most common thieves, who are typically looking for easy targets. Security should always be evaluated in terms of threat profiles.
Not sure if anything has changed but your lighting seems a tad more yellow than usual and it's harder to see smaller details. The inside of the charger itself was quite hard to make out for me personally.
Hey clive, could you do a video explaining the charging requirements for the different types of batteries?
Every time I see that Spludger thingy I think "one day, hes going to loose a finger!"
I like how they have run the listing as "USB 3 slot charger" (or however they choose to spell it) so that it picks up searches for USB 3 charger etc.
Regarding the unpopulated LED, your schematic and explanation are both incorrect. The unpopulated resistor is in parallel with the red LED and its resistor, and the unpopulated LED is in parallel with the transistor (collector and emitter). So the "green" LED would only be on when the transistor is off.
Indeed! Surprised to see Clive make such a trivial mistake.
pmailkeey I don't see what a diode would do there.
Functionally, a diode would have made sense, to indicate (roughly) the charge status. In practice, there would probably be a pretty large overlap where both LEDs stay partially lit, which may be why they omitted the second one.
Mr Carlson's Lab Look yourself and compare. The board is visible at timestamp 6:30 and the schematic Clive drew is visible at timestamp 8:00.
The claim was in parallel with the *existing* LED and its resistor. The unpopulated resistor is of course also in series with the *unpopulated* LED, but that's not what was being referred to.
Annotated board: i.imgur.com/VEbwXzI.png
Corrected version of Clive's schematic: i.imgur.com/WVm92L1.png
idk why but 5:41 gave me a little chuckle looking at what's written on the notebook
What would happen if you put them in the wrong polarity and charge them?
Erm, first they'd discharge....
4:40 breaks plug... 'thats ok i didnt like it anyway' LOL
The slot on the back is for an outlet plug. I've seen battery charger that plug directly into the wall and hang flush. I think that is a double duty case. Not 100% it just looks that way.
the lock slot is good for packaging with a plastic tab to hold the pack in place, like toy cars.
...or screw mounting the battery holder, maybe?
probably for wall mounting nails
With shorted batteries, it might let the magic smoke out of the transistor - or THE USB PORT
How long until you find one that's just wires connected to the USB and battrie contacts
4:01 at this point I really hoped, they placed the charging circuits in the plug.
That colour printout was a great idea!
Does that 1.5 volts max value on the batteries change as they corrode inside? If the permanent logic on that power circuit design has no way of checking the new max voltage of the cell(s), then it seems overcharging is pretty much guaranteed by this device on all but the newest of cells.
The cable used on yours is normally found in cheap products and they all have different end connectors. I have a cheap rc car and it has the exact same cable but it has a connector at the end to charge the battery. They normally have red leds in it to indicate the charge. Usb and cable are always the same on all different types of that cable.
I can see that casing was designed to accept a circuit board in between the cable stay and the cell holders.
will we ever come across the fables - resistor and diode trickle charger soldered directly to the mains - charger?
Don't go giving them ideas! It's bound to happen now. ;-p
I thought the same thing about those Kensington lock slots I had an old laptop and a lock at work and I tried as hard as I could to get it off without tools... kicking it hanging from it, I totally destroyed the laptop and even made a few marks on the desk but the thing never did come free... They are a lot stronger than they look.
These videos are brilliant!
Never heard of a Nickel Cyrdride battery before! Maybe you can take one apart someday.
very cool with the shiny electronics quest.
shiny..
Videos may be released earlier for patreons.
pmailkeey nope, patrons get early access.
well now you have to do a video on how you modify that case.
I think the slot you were commenting on is just to mount the thing to the wall if you want.
First time I've ever seen him put something back together again.
I don't get one thing: you can only use it to charge 3 cells at the same time? What if I want to charge only one? Would the charger try to push that only cell to 4,5V or would it not work at all?
It wouldn't work at all because the cells are in series.
also, unbalance issues may happen, right?
This is a LOT better than that white ZhongJun charger.
Its going to be hard to beat that one.
The green led does turn off when the red is on. It's shunted by the transistor :) That connection is missing in the schematic.
On the plus side yours comes with 4 real screws.
I got one (bundled in with other stuff) that takes all the round lithium ion single cells and they used 2 screws and molded the other 2 screws and holes for them into the plastic.
I suppose it saves a penny every ten chargers.
I notice the extra holes in the USB plug. Is this somehow a USB 3.0 connector?
Could it just be one of those red/green LEDs that change between the two when you reverse the current?
The hole is for a turnbuckle hold down fir holding it into packaging you see them on toys instead of screws or twisted wire
Hi clive, a quiestion. Could the slit be one of those to attach it to a wall with a screw or nail?
Is that slot for hanging it from a screw?
I bought one recently for $1.25 Australian minus 50% because the place was going out of business and I think it might give even this one a run for its money
zman1508 *Ayy M8*
Why do you keep discovering working LEDs within completely opaque casings? Or was there a hole in this casing allowing you to see this one this time? *edit - oh at 5:43 you mention that, sorry, ignore me.
LMAO Clive, Even here in China we don't waste money on these craps. IDK whty they produce that.
i bought a pack of those cheap usb lights, three LED chips and no on/off switch. (uxwbill used one in his "looking for fake solar cells" video recently) i was planning to use it with these small power banks but it's not working with one power bank. it will just dimly flash every half second, and if i charge the power bank just a minute it'll work again, and the lights work fine with my other power banks or in the computer usb port so i'm thinking it's a faulty powerbank. it's brand new so i'm looking for any thoughts?
Jason Halverson it's not faulty, the LED doesn't pull enough current to trip the powerbank's sensor
I can't help but think Clive's symbol (maybe the universal symbol?) for LED's on schematics looks like a :3 face with longer eyes (=3). Kinda cute IMO.
I bought a really expensive charger when I lived in Norway. It had charging indicator lights. The only thing it does is to shine green when a battery is connected. In a way that is a indicator of nothing.
If I can find it, I might have a present for you. The shittiest battery charger I've ever come across, for 18650 cells. I used it only once, because it charged my battery to something like 4.7 volts. It was _extremely_ hot when I unplugged it, though the battery wasn't bulging yet. Probably would have exploded if I let it go any longer.
Came free with a $8 LED flashlight from eBay. I should have known better.
Are you aware of wago 215-311 clamps for plugging in loose wires into ordinary multi meters and other 4mm sockets?
We once got a led torch from ebay- came with a sort of ok mains charger, but the 12v car charger literaly just used a resistor to "limit the current" to the 4.2v max li -ion cell
I discovered it becuse when i used it i could smell the resistor burning and melting the plastic housing!!
I wouldn't put any guarantees on the transistor surviving if the batteries are really flat or short circuit. All the current will go through the B-E junction up to the current limit of the USB power source less than about 150ma for the resistor.
andy fletcher Yes I was thinking the same, seems quite an odd arrangement, even if the current is limited by the USB port. Wonder if its a special transistor to be able to handle that - perhaps with an embedded base resistor like someone else has suggested
Would it have been better to have the 1K resistor on the other side of the transistor then?
I would like to see a resistor in series with the base lead of the transistor. Otherwise, if a high current USB charger is used, the base-emitter junction of the transistor could be blown.
I think the circuit would need a resistor in series with the base of the transistor.
Otherwise, when the batteries are completely discharged, on the base there are 5 Volts and a very high current would flow into the base of the transistor.
That would be great to power a small string on fairy lights... Not that you haven't already considered that application for it...
A family members borrowed my tablet charger and cable and lost it. They replaced it with one from EBAY and when I got it I measured the output and it was live voltage imposed over a 5 volt DC difference of potential. It didn't even have any useful parts for other projects. When I looked inside there was what looked like a Chinese coin taped to the circuit board. I thought "at least I got a coin..". No such luck it was steel slug KO from an electrical box. I think they were using it to prevent rattling, shim?
that T slot is for mounting it on a wall or board or something else.
I never ever had any luck with NiMH batteries. They strike me, from experience, as being NiCd without the 'actually storing electricity' thing.
Other than no cadmium, is there actually an advantage over NiCd ?
Anyone mentioning memory effect gets a chinese shoe warmer...
TheChipmunk2008 I've had better luck. At least according to the packaging, NiMH supposedly stores more electricity than same size NiCd, but less than Li batteries.
I have one from an old 4 battery charger with no name from China, it charges CR123s. I used them in my old DIY laser. But once while sleepy I stuck one in the charger backward and the thing caught fire. I put unplugged it after put it out and it still works. I mean a battery charger with no reverse polarity safety. Why? It cost very little to add that. :P I still have it. Though the batteries and laser are long gone now.
0:10 You don't know Young Huey? lol neither do I
Those holes on the back look as if one version had the board in the battery case and plugged into a wall outlet and hung from the outlet. I could be wrong.
I'm guessing that slot is for a mounting screw. Although having just one of them makes me wonder if the person that designed the case knows how mounting screws work...
Clive, any reason why they didn't include a diode on the PCB to prevent the batteries from sending voltage back to the USB plug? Does the transistor achieve the same result without the need for the diode?
Current could still flow back through the resistor into the USB port. I'm guessing the reason they didn't use a diode is because it would have imposed an additional 0.7V forward voltage drop on the supply, which would have likely prevented the cells from fully charging.
They could have used a schottky diode at around 0.2V drop, but it would raise the BOM by a cent and then they might have wanted a precision resistor, raising it another cent.
Is "spudger" a technical term?
I've bought some 5v usb to 12V DC boost converters...built in the cable on a board like that off eBay...they work pretty well for a dollar....one gives me 12.05 and the other 11.86 consistently....I like them for using a usb battery pack to power my evil mad scientist electrical projects that need 12v to kick off ....only thing that sucks is they are low current so a 12v 1W laser isn't happening even with a control board or TTL
I wonder why they felt the need to put the circuitry in the plug? It seems like it would be easier to just put it in the case.
you have an error i think, the green looks to be connected to the switched transistor too so the green would go out when the red was on.
6:30 At first glance it seemed to me that there is a smiley with a mustaches next to the LED.
+bigclivedotcom, I'm not sure where I ever read it and can also not verify if it's true, but the Kensington lock (or whatever it's called) was said to be designed in a way that it causes a lot of damage if you actually try to steal a device locked to one of those kind of cables, by either ripping the chassis open at a "tactical" place to render the product completely useless, or make it appear so badly damaged (though maybe still working) that you are unable to sell the stolen goods.
I like your optimism. Shitty charger but a fairly good case! :-)
You could possibly go even lower than that. No electronics, just an LED in series to lose about .5V and get 1.5-ish V across each cell.
I have a question related not to this video, but am curious nonetheless; do you live on the Isle of Man, or were you just over for TT? I saw the meet up thing you did but must admit I was too much of a fanny to come down. It would be nice to think I might run into you some time if you do live here :)
Dan Reader - yes, BC lives on the IoM
awesome. Let's get a pint sometime and drunkenly ogle sophisticated electronics!
Those slots on the back of it remind me of what you'd see on the back of an old landline telephone to hang it on the wall. But those look too small to be used for mounting. And they're not really in the best position for it.
The green LED is connected to the transistor and should turn off when the red LED is on.
Clive, I have a spare wismec predator mod for an electronic E cigarette. It's spare as unfortunately it is faulty. My only conclusion now is it may have dropped and the usb port is broken and the way it detects ohms is not correct for the coils. I have tried taking the board out as I have seen people slide it out but mine won't.
I would love you to have the honour of taking it apart and showing the people of your channel how a more advanced e cigarette battery works and how it detects that charge state of the cells. It would be very informative for me too.
Can you please get in touch with me or give me a way of getting in touch with you so I can arrange getting this sent to you? Thank you.
Gareth
How does one get ahold of you?
Maybe add a dob of white paint on your multimeter's dial so it's fractionally easier to see where it's set?
I'd imagine the 500ma limit from the usb port prevents the transistor from going pop
What about 1 amp USB ports then?
Inserting the batteries the wrong way around might make it a smoke machine. Worth a try?
Im blown away they can even turn a profit sellimg at that price, i cant imagine many people buy this workshop rejects perhaps even still after postage how do they do it?
I bought a torch that came with a charger for its lithium battery, all it had inside was an LED in series with the battery
I once got an USB single 18650 Liion cell charger which was really just directly connected to the USB port, no resistors, nothing.
You know it's cheap when they even save on the base resistor for the transistor.
Clive! I have a ALLSTART boostmax 560. It's 6 months out of warranty. Booooo. The jump start portion of the unit works but the outputs for the USB are not. I would like to send it to you for disassembly buddy. Where do I send please 👍👍 thanks mate
Carlo