Dead solar lights.

The random black dots in the dead lamps makes me think they've had more than a simple overcurrent experience, especially as the solar unit has a current regulator set for 220mA (about .7W at 3V) meaning that a single lamp would handle the current on its own.
Thanks to the wonders of zero electrical standards the lighting loom on this string of lights is full compatible with one used for 120/240V lights. That makes me think that someone without proper electrical knowledge has tried to extend a higher voltage set with this solar string and in doing so, blown every single lamp. They have then probably returned the set they destroyed as being "faulty".
It's interesting that the phosphor gel covered LEDs actually break high current in a controlled manner like a fuse without exploding. Previous tests have shown that they are almost boring when overvolted. It's likely that the gel contains the fault in a controlled manner without letting a metal arc form from the failing tracks and bond wires.
There is a single chip solution for powering LEDs from a single lithium cell, but in this instance the designer has gone with a fairly complex circuit using some novel components to achieve a more customisable result. The large solar panel looks promising. I just need some sunshine to test it.
The 18650 lithium cells are each marked 1800mAh with a date code of 2021 and are branded Yueyu.
Their actual capacity came out closer to 1000mAh.
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 KZbin's algorithm quirks, allowing it to be a bit more dangerous and naughty.
#ElectronicsCreators

[@Schlups]

This is ingenious. The "magic of buying two of them" can now be replaced with the "magic of buying a broken one and getting a free replacement".

[@-Jethro-]

It looks like the 18650 cells are easily replaceable. That’s excellent, I wish all rechargeable devices were designed this way.

[@markfergerson2145]

Like a lot of things that’s a tradeoff. Being able to replace cells is good if one or both die, or if the ones supplied are low capacity. Cells that are spot welded or soldered (spit) in circuit are far less likely to suffer corrosion at the contacts or to jostle loose under physical shock. For folks like us who automatically disregard those “no user serviceable parts inside” labels they are very good on general principles.

[@brentengelhart5]

We're suckers and we realize that fact.

[@-Jethro-]

@@markfergerson2145 Label: “Warranty void if opened” Us: Challenge accepted!

[@PhilXavierSierraJones]

Many of those bigger solar lights on Ali with two buttons on the back have replaceable AA cells inside!

[@mindaugasstankus5943]

@@markfergerson2145 Tradeoff? Protection from moisture water intrusion and corrosion my guess?... BS mainly. Soldered and welded cell leak nicely and eat all traces around or just die couple years in, no different from socketed ones. Soldering in is penny pinching and "planed" obsolescence, a specially components with very limited life span or shelf life.

[@LakeNipissing]

My "solar" lamps were amazing... they were as bright as the sun for a fraction of a second ! Now I'll send them back, because they've gone dark.

[@KeritechElectronics]

Unlike the sun, not rising again? Oh well...

[@originaldcjensen]

I have a camera that uses bulbs that do that…if you can find them.

[@LakeNipissing]

@@originaldcjensen I know what you speak of. I still have boxes of cubes and flip-flash units for the old Kodak Instamatic cameras!

[@mistermeaargee2670]

The problem we have here in Aus is the violent daytime sun. It kills off the coating on cheapie solar panels in 1-2 years.

[@amorphuc]

I've noticed this too in the desert in Idaho. I'm experimenting with automotive wax as a protective coating and thinking about UV resin or cutting glass to fit over them.

[@matthewellisor5835]

​@@amorphucI've had good luck with a thin piece of glass. It did reduce the PV output 5-10% but that's no trouble in my scorching summers the South East USA. Sadly several weeks of 100+F (~38C) highs and 80-100%rh un alives quite a few (typically elderly who can't afford air conditions or the infirm) every year.

[@Alabaster335]

Rural QLD here, only takes 1 summer to kill a cheap solar panel.

[@gary_rumain_you_peons]

It's the resin ones that fog up. I've complained about this before and Clive once mentioned that you can clear them again but I couldn't be bothered. However, the glass ones last for ever. I have a set of garden solar lights that are glass rather than resin. Over 10 years old now and still fine.

[@rolls_8798]

and most cheap plastic in general

[@k.o.0]

I purchased this same unit off Amazon. Probably the best solar lights that I have come across. Running 4 seasons with cold winters. The USB port is to charge in winter if insufficient sunlight. Never used it. They emit for several hours in the summer months and the bulbs look nice. Glad that you ripped it apart before me! I imagine that once the lithium batteries are spent, I will be replacing them so at least I know what’s inside now! Thanks Clive. Love all your videos.

[@BLKMGK4]

Link to the item?

[@quantumleap359]

I just noticed Big Clive has hit the 1 million subscriber mark! Congratulations sir, well earned and deserved! Keep these excellent videos coming.

[@HelenaOfDetroit]

The amount of effort it took to reverse engineer this had to be wild compared to how quickly you were able to explain it. Thanks for helping plebs like myself learn even more!

[@sarathai2876]

A lot going on in that circuit. I love how you reverse engineer things and come up with a wiring diagram.

[@blairhoughton7918]

I took a picture of the screen with my phone and used Google Lens to translate the QX7136 diagrams, and the left one is "low voltage application" and the right one is "high voltage application". Ironically it means the chip itself can sink all the current from several lamps in parallel, but not handle the high off-voltage from several lamps in series, so it needs the external FET even though the current would be much lower. I bet the low-voltage configuration can't support nearly as many bulbs though.

[@armin7515]

bigclive saying "one moment please." just makes my day!

[@-Jethro-]

I’ve started saying it, too. In my head I sound just like BC!

[@billide1463]

Your avalanche comment reaffirms the state we technician/collectors/hoarders find ourselves in when we experience 'settling' of the hoard; a frequent reminder that we need to purge. Garbage-lanches happen to me all the time. senior from Canada

[@jackpreston8762]

I watch all your videos over the years and you have been a real inspiration to me and I realised that I haven't said thank you for all you do. So thank you Big Man. Long may you keep going inspiring lots of people and making people's lives just a bit better, again thank you.

[@chrissmith7655]

HI Clive, 1,000,000 subs HOORAY!!!!! Thanks to all subscribers, he WELL DESERVES THAT!!

[@tubastuff]

I've got a number of flashing solar LED beacons along my otherwise-dark driveway. They're sealed units, complete with O-rings and rated for marine use. After about 4 years, they've started failing, one by one. The culprit turns out to be the soldered-in NiMH cells (1 per light) reaching the end of their service life. There is a bit of corrosion on each cell, but they're replaceable.

[@ericblenner-hassett3945]

I would guess the current regulator is the Q varient. It apears that when the voltage is too low it will cut off the lights and save the batteries from over discharge. I am also amazed how well the circuit was designed and implimented into such a small package looking like the space to mount the switches was the size limiting factor.

[@gregorythomas333]

A redesign of the connector seems to be in order...a simple pip addition could help make the low voltage one non-compatible.

[@SeanBZA]

Terrible in the factory though, as they now need to have a second set of moulds. Single set, and accept people are stupid, will ensure more sales.

[@HelenaOfDetroit]

It's one of those "make something idiot proof and the world will produce a better idiot" things. 😂 But there could be an adapter created that could be put between these two different strings. And ya, I'm being silly with the first sentence as there really should be some marking or something to make it obvious.

[@gregorythomas333]

@@HelenaOfDetroit You may consider the sentence silly but sadly it is too true. Having to put a warning that coffee is hot on a coffee cup is proof that idiots keep getting more idiotic every day!

[@Knaeckebrotsaege]

@@gregorythomas333My ethernet network switch came with a lampcord style inline switch between the PSU brick and the plug that goes into the device. It seriously had a sticker on both the PSU and the network switch stating "This device will not function if the switch is turned off". The world needs a whole lot less warnings. Let the gene pool sort itself out. _Pleaaaase_

[@tactileslut]

I would tie a knot in it and attach a keyring tag reading "low voltage."

[@JoeyBlogs007]

They're not dead. They're just waiting for Christmas.

[@amorphuc]

So fabulous. Thanks Big Clive. I appreciate the dedicated hours you work to bring us this content! So informative and fun!

[@amorphuc]

It IS interesting the manner in which they failed. You'd almost hope for a pop and soot covered glass on the bulbs LOL.

[@dcallan812]

Nice lights, shame they use the same connectors for mains and solar. But the bonus is you now have 1 spare solar panel that contains 2 good lithium cells free. 🤣🤣 great video 2x👍

[@gertbenade3082]

With a nice solar panel like that, one can upgrade the cells and even hack this and add a 5V USB output stage for phone charging out in the bush. Thanks Clive!

[@pauljs75]

It's always fun to see the results of standardized components that lack a fixed specific standard to go with them. But at least you got some free bits to mess with out of it.

[@ferrumignis]

The 100k across the solar panel will be to compensate for the reverse leakage of the Schottky diode which is much higher than regular silicon diodes.

[@briantaylor9266]

Prompted by your review, I purchased a set of these lights on Amazon ("LE Outdoor Solar String Lights, 25ft 26 Units G40 Edison Bulbs USB Rechargeable or Solar Powered Patio Lights Waterproof for Indoor Outdoor Garden Bistro Festival Decoration, Warm White"). They came exceptionally well packaged with each bulb individually cradled in styrofoam. The instructions that came with them were well written in clear English, and provide a warning that the bulbs are 3V and that they must not be connected to high voltage.

[@stephennorris6150]

I have a similar one (with USB-C input instead of micro USB). As it gets dark it flashes at about 1Hz. I assume this is because the light from the LEDs is enough to make the panel produce enough power to make the micro-controller think it’s day again. Once it’s fully dark it’s fine.

[@45KevinR]

Very likely. I have a security camera with infrared leds about 3m up and it was just strong enough to stop one of my solar wall lights 2m up from turning on. I used part of a plastic tray to make a light baffle on the wall between the two devices. Problem solved and not that unsightly. I didn't expect 2.5w of infrared to be enough to do that.

[@haroldsmith45302]

Thank you for the effort you put into these forensic investigations and the detailed reverse engineering. They are all interesting.

[@connclissmann6514]

Really impressive finding all those days sheets, helping your long reverse engineering process. Always appreciated, of i not so commented before. Those connectors being interchangeable appears to be at the root cause of the meltdown. Thanks again.

[@planker]

Excellent. I live in Arizona and Dollar store lights are getting interesting. Rebuilding these things is quite fun.

[@kean4218]

I love this channel so much its amazing how much you though me about electronics. thank you

[@liam3284]

Surprised at the effort they went to with this.

[@martinclemesha4794]

I have a set of these, which have been outside for 2 years. The only issue I had, was with the bulbs, which allow the ingress of water. Not a lot, and the led still works. These light my garden quite well, and seem to last most of the night this time of year.

[@perdiddlepanskew8018]

So cool to see how they work!

[@curiosity2314]

Congratulations with hitting the one million mark!

[@FearlessLeader2001]

The previous owner was clearly a fan of the scientific method; blasting an entire set of lightbulbs with 240 volts, then trying again to make sure it would have the same effect.

[@wiseoldfool]

"Let's open it up". Words of joy!

[@GeorgeStyles]

That thing looks like a perfect project box for esp32 controllers and suchlike, with a built in power, solar and charging circuit, and waterproofing.

[@wisher21uk]

Brilliant love the solar panel unit it’s so hackable thank you 😊

[@Darieee]

lovely ❤, thanks for taking the time clive !

[@M0UAW_IO83]

My mother has a set of these lights, so far, excepting a smashed bulb or two and a bit of corrosion in the bulb sockets they've been great, they're on their second winter and are going strong. I think you're right about the overvoltage, replacement bulbs are bit awkward to track down (smashed bulbs) and there are 240V versions in the same package so, as you kind of said, maybe someone saw these sets and bought them to extend a 240V set

[@ericpaul4575]

Clive could just get the 240v bulbs and upgrade his broken string . I bet the wiring gauge on string is the same for both version.

[@25566]

i have the same lights they're very bright, my set also has a remote. I knew it had two 18650s but I didn't think they would be replaceable. I like the product for how user friendly it is, replaceable standard bulbs and batteries

[@LygerTheCLaw]

i have had a set of these for a while, they started acting erratically after about 3 months, they'd turn the lights on during the day and no longer turn on at night. i think the issue is once the 18650's become weak the controllers lose the ability to determine whether the solar panel should be charging or running the lamps. the circuits seem to be either trying to charge or trying to power the lights(unless the switch is off). both my 18650's seemed to be ok voltage wise but i didn't run any actual tests on them. id say the downfall is the batteries cant maintain a daily usage on all these lights for more than a few months without needing to be replaced. i was trying to understand why there was no light sensor when i took my panel apart a while back, but you explained my theory that it was simple current based logic.

[@craignehring]

Amazing where LED's have evolved too Thank you Master Clive

[@melkiorwiseman5234]

I've been running a chain of around a dozen LEDs from a Li-Ion protected cell which is switched and charged via a circuit I found on a web site. The circuit uses 2x NPN transistors (2N2222 or equivalent), 4x resistors and a diode. It turns the lights off and on automatically and allows the cell to charge when there's sufficient current. The solar panel doesn't provide sufficient current even in full sunlight to stress the cell, and the protection circuit prevents the cell from being either over charged or over discharged. So far, it's been running for roughly... 4 years? 5? Something like that. They provide enough light in my carport so that I can see where the keyhole is even if I have to return home late at night and I forgot to leave the outside light on. I have another set of lights which used to use a circuit similar to the one in this video (and a virtually identical case), but that went dodgy (I think due to corrosion of a switch) so I changed it over to using the same switching circuit. The one thing I need to do is to add a second protected lithium cell in parallel since only one doesn't last long enough with such a long string of LEDs to drive.

[@kimsleep4111]

In the days of a single chip inside Solar Lights,,, these are truly amazing in their complexity

[@eh42]

I'm just gobsmacked that there are LED strings with consumer replaceable bulbs!

[@zh84]

The REALLY scientific thing to do would be to put 240V across the "good" set and see if they fail in the same way. That would be strong evidence in favour of your theory ;-)

[@TomCee53]

😅 I know you’re joking, but it would have been interesting to see one of the low-voltage bulbs tested in the bulb tester at 240v.

[@Alabaster335]

And a set across a large capacitor bank, in the name of science...

[@Ni5ei]

Nah, LEDs on high voltage usually fail in a non spectacular way.

[@zyeborm]

​​@@Ni5eithat just means you aren't using enough of it😂

[@RS-Amsterdam]

And claim a third set😅

[@cmuller1441]

I have Christmas lights that have that connector and uses a 24v transformer (AC I think). That's probably enough to kill the LEDs.

[@thomaskrechel]

I´ve got that set in the 230V version. After a couple of weeks several of the bulbs were dead. I contacted the seller and they sent me a complete Set that obviously was a return as it would blow the circuit breaker when plugged in. After a brief search I found one of the bulbs with a bent base so the tip did make contact to the thread.

[@harisdilberovic6528]

Ave frowns upon not using unnecessary tools :)

[@d.t.4523]

Thank you. Keep working, good luck to you.

[@pmpwiz]

Not too impressed with the lights but... that solar panel has my attention! Love the design 😍

[@richardbriansmith8562]

Awesome Video Big Clive

[@RousePartridge]

" Solar energy isn't going to replace coal overnight " - Gerald Ford Pres. USA 1976

[@maciejzettt]

But is more likely to do so over 10 000 nights :D

[@darrenglynn597]

🎉 Congratulations Clive , you have made the ((ONE ) Million mark on subscribers well done as you are very entertaining with (Cock ups on design faults) and how badly the circuit diagrams . Thanks again could you tell me what plug socket that you use that reads the power consumption is it the (Hobi) if I have spelt it correctly. Thanks again 💯💯💯💯💯💯💯

[@bigclivedotcom]

Hopi.

[@frankowalker4662]

A neat and very busy circuit.

[@SeahamV2]

Congrats on 1mil subs big fella!!!!

[@Shady97342]

Clive did you hear there was another incident of an event installing improper UV bulbs causing eye and skin damage? I wonder if it's carelessness/lack of knowledge or cost cutting attempts (are the disinfecting bulbs cheaper?) "Attendees of Bored Ape Yacht Club's ApeFest concert have reported experiencing extreme eye pain that's prompted some of them to visit the hospital."

[@offdagrid877]

I’ve got one of these on my summer house lasts all night in the summer, nice to see that the cells are replacable, unfortunately some of the lamps are starting to fail, looking at the connector makes me think I could plug in an led strip or the like maybe.

[@TheSpotify95]

These are very nice lights, I have a set myself of these that have been outside for about 2 years, and have been by far the best set of solar lights I have had. I've only needed to use 1 out of my 2 spare bulbs and they all work nicely, but not as well in the winter... at least you can charge these up via Micro USB if required! Like yours, my 18650s were under capacity but IIRC I measured mine at 1800mAh instead of 1000mAh; mine were originally claimed 2200mAh. I do have plenty of spare 18650s from laptop battery packs which can be used (and easily converted to button top via a blob of solder). It's just a shame that these are designed in such a way that the 3.6V solar ones can be "extended" on to the end of a 240V AC set...

[@BenJandrell]

Congratulations on reaching the big million subscribers... have a zesty beverage. 😊

[@matthewmiller6068]

It's entirely possible that the listing was wrong and they didn't really understand the implications of the solar panel indicating it wasn't 240 volt... I ordered some 12 volt fairy lights off Amazon and after connecting them I was musing that it seemed like the colors were wrong... And then when I went to move them it was too hot to touch and started melting the stuff it was sitting on. I eventually worked out that I think maybe they were selling 3v or 5v fairy lights as 12 volt, and since it fit the generic barrel connector on my power supply I didn't think much of it. I'm just glad I realized it was a problem before it became a fire.

[@davelowets]

Many LED flashlights use a variant of the 7136, the 7135, to drive the LED. I.I.R.C., the 7135's deliver 400mah each, and some lights use them in parallel to deliver more current to the LED, or they're switched in and out for various light levels.

[@twocvbloke]

If those bulbs are E10 base, then that explains the previous vid on printing custom bulbs, a DIY festoon of a mixed bag of odd lamps in various shapes and sizes... :D

[@Knaeckebrotsaege]

I have two older LED string sets (non-bulb type, just little 5mm (?) LEDs with the weird cone shape built into them so they light all around them and not just into a spot) that both also use this connector, but one is 24V AC with a bulky potted linear transformer and the other is 31V DC with a switchmode PSU. Even those would've probably killed the LEDs on this bulb set. At 240V it would've probably been _a lot_ more violent (I'd expect smoked bulbs and/or skidmarks at that point)

[@daverei1211]

Thanks Clive. I really worry about 18650 Lion batteries in these kind of outdoor solar lights without any ventilation. Here in Australia the average day is 35c air temperature in summer (peaking to 40ish) while this box is in full sun and charging the battery- best case it shortens the life of the cell … worst case of overheating could be very bad.

[@NinoJoel]

If you think thats Bad i got some good news for you. They sold USB power banks with Lithium polymer battery's ( the soft pouch ones) and it had the battery directly glued to the solar cell which reached well above 70° in the sunn. 😂

[@hockeyguy820]

@@NinoJoel : I bought a power bank like that quite a few years ago on eBay. The small solar panel on one side of the case is impractical at best, and a scam at worst. In direct sunlight the solar charge current was only about 50mA which means it would take about 60 hours of direct sunlight to gather enough total energy to charge my Android phone. That's crazy. And yes, the unit gets extremely hot in the sun. Not good for the lithium cells. To make things worse, and here comes the "scam" part, the power bank has circuitry that wakes it up in fairly low light, i.e. when the solar panel voltage just comes up. Once woken up it starts lighting and flashing LEDs that indicate it's charging, even under indoor lighting. The problem is that regular indoor lighting is not enough to supply any charging current, and the unit is actually draining the battery to look "active and charging". The bottom line is to never buy a power bank with solar cells attached to it. Always buy a separate panel so you can plug into batteries you keep in the shade.

[@10100rsn]

"There's a current sense resistor down there ..." Listening to you say that at 2x speed made me choke on my Dr.Pepper. Almost spit it all over my laptop. Really didn't sound like "current" at all.

[@ymirthefrostgiant]

Thanks friend.

[@scotts.2624]

They filled the order for the name brand contract and still had material and machine time available. Once a production facility hits that point minus labor its free money.

[@jan-pcro]

good video! ❤

[@ChongMcBong]

these are nice, cheers Clive :)

[@gblargg]

I had some RGBIC lights with a poor 3-pin connector that could be rotated. It has +5V, GND, and data. Each LED receives color data, then passes it along on its data out to the next one. The connector was put on wrong for a second and it took out 6 or 7 lights in series. If you rotate the connection you can't reverse polarity, but you could e.g. have +5V on GND and GND on data, putting a negative voltage through data. Somehow each LED passed a negative voltage on to the next, and to the next, but it didn't blow them all out. After cutting out the bad LEDs I added a 1K series resistor to DATA after the connector, so future misconnections won't be able to put enough current to blow anything further.

[@restojon1]

The point you made about the connector blocks of the low and high voltage looms being compatible is worthy of discussion. In my experience, electrical and electronic equipment in the UK has historically been manufactured in such a way as to "idiot-proof" it, especially when you consider connector blocks and plugs. For example, small tangs, different shapes of blocks and male and females being connected in such a way that it's not possible to connect your sparky item incorrectly unless you are really spesh. With the advent of global trade and so many companies overseas competing for such a tiny market space, such "niceties" as not murdering the operator or burning their house/office down is reasonably far down the list of priorities, somewhere below; Make it cheap. No, cheaper. Fuck it, we'll use sellotape. We need to be more stringent enforcing this kind of safety measure because at some point, there's going to be another Grenfell or something of that magnitude caused by badly manufactured items bought cheap because none of us can afford socks anymore due to the cost of living crisis.

[@merlynsfire1275]

"a small avalanche in the background", finally a connection to my workshop :D

[@davidfalconer8913]

This is a quality product ! ! ..... It is a ( sad ) fact that a good many non technical folk think that LED's are just a modern version of the Tungsten filament bulb , and are not aware that LED's MUST have a current limiter ( a resistor costing pennies / cents will usually do ! ) , never mind , you get all those FREE spare MES sockets ! ........ DAVE™🛑

[@JuulCPH]

My experience with the epoxy (or fiberglass as you call them) panels is that they yellow with time. The ETFE panels don't have this problem but don't breathe the smoke if they catch on fire.

[@TheBurnsStuff]

I have a set of these. They are nice lights for a patio area.

[@6am_Doug]

Hi Clive, Have family on the IOM also who have similar issues, I do receive various packages for them from mainland and ship out to the island once a week. If you’d like anything sending out let me know I’ll forward onto you. Am back over visiting family early next year, might see you in the pub again 🤣 cheers

[@jimg3466]

Grats on a million subs

[@BG101UK]

Having interchangeable connectors and lampholders across LV and 240V is just asking for trouble. I remember motor-factors selling 12- or 24-volt 50W GLS-style lamps for automotive use, with E27 base, not realizing E27 would soon become common in the UK for household use, Imagine accidentally screwing one of these in the posh Ikea fitting in the dunny. You'd end up with a flash in the pan.

[@areheptus6566]

Man you are the reason why i am in relationship with my studies

[@Hex-Mas]

I have the same solar kit lol I use it for LoRa

[@Lizlodude]

I'm imagining a string of 50 flashbulbs when they original user plugged the poor 4v LEDs into 120v 😅 but it probably wasn't even that exciting.

[@joelmurphy9369]

Will you please plug a working string of 3V lamps into a 220V lamp string and then plug in the 220V lamp string in to that crunchy plug tester that you have? And then turn it on? Please? Just so that we can see what happens?

[@NinoJoel]

At that voltage they just pop and that's it. Nothing to exiting

[@stargazer7644]

He already told you what happens, and it isn't very exciting.

[@bwack]

Neat. I liked the constant current part of the circuit. I looked up the attiny204, could have been the mystery mcu, but I guess it would be too expensive for this. Probably it is a chinese brand mcu in use in this circuit.

[@nerys71]

I really wish I could find a nice set of solar lights like these the bistro string lights with a nice big solar panel that uses a lithium-iron phosphate battery

[@NoMoreBsPlease]

At least you wait until you have a second one to tear yours apart 😂 I'm too curious, I have to know!

[@nerys71]

That's interesting that the panel you like is the panel that I hate I won't buy units with that panel unless there's no other option I call them in capsulated solar panels The reason I hate them is because of the epoxy resin capsulation They never use UV stable resin so inevitably those solar panels become opaque when they fade in the UV light You can polish them to restore them but then it's just going to do it again and you can only polish it so many times before you wear out the UV resin and start damaging the panel the panel that you see is the kind I prefer or glass panels because they won't fade in UV light

[@PhilC184]

When my similar set failed it was because one of our local squirrels chewed through the cable.

[@NOWThatsRichy]

Ive had that same problem with foxes, several times in the past!

[@elfnetdesigns702]

seems they would have a different connector types for the high voltage and low voltage strings so they cannot be put together.

[@Eddy-NOR]

When regulating current to all paralle bulbs, then if one fail, remaining will get more (over) current

[@lloydevans2900]

That's the first time I have seen a set of these solar powered LED lights with lithium ion 18650 cells in them. All the other ones I have come across use Ni-MH cells, usually AA size though some of the really small ones which power a single LED can use Ni-MH button cells. The AA size cells usually have at least 600 mAh capacity, with some having 800 mAh or even 1200 mAh, depending on the size of the solar panel and how many LEDs it has attached. Though I recently came across some "solar powered pebble" night-lights which work the same way, also with Ni-MH AA cells, though with only 300 mAh capacity. Which was a bit of a surprise - I have no idea how you can actually make cells of that physical size have such a pathetically low capacity, whoever made them deserves an ignobel prize for figuring out how to make cells which manage to be so utterly crap as that. Has anyone ever come across any AA size cells (either Ni-MH or Ni-Cd) with a lower capacity than 300 mAh?

[@someguy2741]

Maybe the first set was black light and are working fine.

[@demef758]

The little current regulator chip (U4) needs an external FET (Q2) because presumably the amount of current that U4 would have to handle is higher than the chip can handle. U4 is a linear IC that requires classical transistors (either bipolar or MOS). A power transistor like Q2 has a special process optimized to handle large currents using a small die size. The linear device COULD incorporate a much larger transistor that could handle the larger current, but the increase in die size would increase the chip cost substantially. It's far cheaper to reduce the size and cost of the linear IC and tell the customer to buy an external pass transistor for a few pennies more. Cheap consumer electronics is a case study in cost control!

[@johnnodge4327]

I've had the same unit outside for a couple of years. The solar panels unit is fine. The bulbs have pretty much filled with water, so only a couple now work. It was good before the bulbs started to fail though.

[@Franksey180]

Can you share a link to where these lights can be purchased from?

[@johnnodge4327]

​@@Franksey180 I got them from Amazon UK in 2020. They cost under £20 with Prime.

[@AnthonyCartmell]

We have a set of these, they're seemingly good quality. The lights flicker on and off rhythmically when the batteries get low, possibly switched by that current sensing chip in "minimum current" mode? I would have expected the main microprocessor to have some hysteresis in its voltage sense input to prevent oscillation

[@wherami]

Very interesting. I bought some cells recently that make my own solar panels for hydrogen fuel cell work

[@gedtoon6451]

It sad, but it is probably cheaper to by the whole thing than to try to buy replacement bulbs. Absolute madness to use the same connector for 240V and 3V LED strings!

[@Slikx666]

I see a project with that solar panel at some point. 🤔👍

[@lukehahn4489]

Clive's one of the few who is tickled to receive bust electronics

[@kierank01]

The circuit board is dated 2019, so may not have had the one-chip options available at that time

[@Foxtrot_Foxtrot_Lima]

You could use half the paper if you printed on the back side also.