Lethal LED Lantern Leaks Lotsa ‘Leccy

When you take an item with you on a camping trip and it fails, you are not normally in a position to replace it immediately, thus you have the choice of fixing it there and then, or doing without it. When his LED camping lantern failed, [Mark Smith] was in the lucky position of camping at a friend’s compound equipped with all the tools, so of course he set about fixing it. What he found shocked him metaphorically, but anyone who handles it while it is charging can expect the more literal variation.

The lamp was an LED lantern with built-in mains and solar chargers for its Ni-Cd battery pack, and a USB charger circuit that provided a 5 volt output for charging phones and the like. The problem [Mark] discovered was that the mains charger circuit did not have any mains isolation, being a simple capacitive voltage dropper feeding a rectifier. These circuits are very common because they are extremely cheap, and are perfectly safe when concealed within insulated mains-powered products with no external connections. In the case of [Mark]’s lantern though the USB charging socket provided that external connection, and thus access to a potential 120 VAC shock for anyone touching it while charging.

Plainly this lamp doesn’t conform to any of the required safety standards for mains-powered equipment, and we’re guessing that its design might have come about by an existing safe lamp being manufactured with an upgrade in the form of the USB charger. The write-up gives it a full examination, and includes a modification to safely charge it from a wall-wart or similar safe power supply. Definitely one to watch out for!

If you were wondering what the fault was with Mark’s lamp, it was those cheap NiCd batteries failing. He replaced them, but there are plenty of techniques to rejuvenate old NiCds, both backyard, and refined.

39 thoughts on “Lethal LED Lantern Leaks Lotsa ‘Leccy

    1. The funny thing is that this guy replaced his AC with a wall-wart, but big Clive showed that some of those are really unsafe and run the risk of putting out high voltage, so you are back to square one.

      Also I suspect they often enough stamp/print/mold the UL logo on stuff when it wasn’t actually tested. I think Big Clive also shows there is reason to suspect that.

      1. There is no “China Export” mark. It’s just a poorly drawn CE mark. In other words, the manufacturer knew that a CE mark would give the product credibility, but he didn’t research it carefully and just used something that looks like a CE mark.

      2. The China Export mark being an intentional near miss clone of a CE mark is made up and just keeps endlessly being repeated without any evidence. Nobody is China is actually doing that. They’re just slapping on a CE mark which they didn’t design very well. The CE mark shouldn’t be on the products for obvious reasons but it intended to be a CE mark and it isn’t a China Export mark.

        Read http://www.europarl.europa.eu/sides/getDoc.do?type=WQ&reference=P-2007-5938&language=EN and then click the answer button.

    1. C E is only part of the story that covers mostly just electromagnetic immunity and emissions (IEC 61000). And as we all know, everyone can apply that to his device, it’s a self certification. It only gets the guy/company in trouble that was signing the CE confirmity declaration in the first place if “shit hits the fan”. Good luck finding and sueing that chinese farmer that signed this declaration…
      What it should have is a safety certification according to IEC 60335 (Safety of electrical household appliances) or similar, usually verified by localized bodies, like UL, CSA, VDE, BSI, CCC and so on, depending on the market the device gets sold in.

      1. You can’t sue a chinese manufacturer for CE violation, only the importer of goods is liable under EU law.
        At most you can sue them if it’s part of the manufacturing contract, but otherwise on-the-self buyers will be bitten, with good reasons.

        1. The EU should grow some cajones and taxing the country itself for allowing export of goods with such a mark that were not accredited. It needs to make another mark that you have to submit paperwork to an EU agency. Next to the mark will be a hex number unique to the product.

          Any country caught exporting fraudulently marked devices with this new mark would be fined. If they don’t want to pay the fine the fine will be taken out of all future imports form the country from the next would be shmuch importing stuff on a percentage basis.

    1. The cheap stuff that is meant to fail on purpose and hopefully destroy it self…. That way the average pleb would think they got a bad one, bin it and buy another making it a winner for the manufacturer: If the buyer is still alive.

      1. Unless…. you referred to the repairer, then his reasons were probably one of the following:
        A. Li-ION+Mains+cheap_components == Bomb.
        B. Probably had no safe Li-ION use paraphernalia at the workshop.
        C. Ni-Cd maybe the only thing he had to hand at the time.

    2. You might be surprised by how many people have looked at lithium cells finickiness, plus high cost per (non-standardized) battery package and decided to take a pass on them.
      For devices like small cameras, a *pair* of good, rechargable “AA” cells still offer more capacity for only a few grams more weight than a lithuim, package which only has about half the watt hours of the “AA’ cells.
      And does it at about half the price of the lithiums.

      Did I mention that you can use that same “AA” cell in many different devices, Thus not needing a bastard battery package for everything you own.

    3. Those who think about longevity of batteries and survival when misused.
      My personal horror story – ~55Wh pack of NiMH. 12v. Was accidentally shorted against a computer case and left overnight. End result: brittle heatshrink wrap + minor issues. Loss of about 1/3 of capacity. Still worked after that.
      What would have happened in case of Li-Ion – I prefer not to think.

  1. I thought Ni Cd’s were history. China will export anything, including the west’s waste.
    Lantern shaped lighting devices seem so out of date in the age of directed LED’s.
    Must exterrrrriiiminate!

        1. LOL….
          Except in this case they’re just wannabes trying to enforce the Darwin Gene-pool mechanism… one customer at a time:
          if the pleb survives the shock and possibly the resulting heart attack, then they’re strong enough to multiply half their genes.

    1. Cadmium is a no no in the EU because mammals tend to confuse it with oestrogen. ( https://www.newscientist.com/article/mg17924041-500-is-cadmium-a-gender-bender/ ) Lows of biological implications here, particularly for the male of the species. Still found in other countries because NiCad cells typically have a lower internal series resistance then a cost comparable NiMH cell.
      Some other developed countries like the USA is not the concerned with the health of their mammals, humans included.

      1. Well.. there is always the option of not ingesting your batteries… just saying!

        Oh.. you are worried about discarded batteries leaching into the water supply? Most US states have a pretty successful empty soda can/bottle rebate program. Maybe it’s time to extend that idea to some items which are made from more harmful, reactive chemicals…

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