Bests & Worsts Reviews from Amazon

Right out of the box I heard something rattling around in the base of the unit... very bad. My first impulse was to return it, but then I figured for $11 what the heck, let's take this baby apart and see what's wrong. In so doing I made some discoveries about how this thing works which I would like to share with you. My immediate problem (the rattling noise) was a rather large capacitor which was supposed to be attached to the printed circuit board. So in less time than it takes to print the Amazon return label and drive to the UPS store, I had the capacitor soldered back in place. Problem solved, but you know that once you have the hood up you just have to have a look around. One thing I discovered is that the charging circuit is transformerless, which you could pretty much guess by the lack of a wall wart and the overall light weight of the lamp. Transformerless chargers of this design are cheap and potentially dangerous, here's why. A proper lithium ion battery charger continually monitors the battery voltage as it charges. If the voltage is too low, it will cut back the charging current (amps) to avoid damaging the delicate battery chemistry until a sufficient charge is detected. A good charger will also detect when the battery is fully charged and shut itself off, or go into a trickle charging mode to keep the battery topped off. The GREENERY desk lamp's charging circuit lacks all of these features. The only thing it does is deliver a steady 4.0 volts to the battery. The proper charging voltage should be close to 4.2. Cheapo chargers like this one purposely keep the battery undercharged at a low current so they don't have to worry about monitoring the charging process. (This is the reason the little red indicator never turns off.) Here's the problem. If the value of any of the cheap components in the circuit changes, the charging voltage could change to exceed the 4.2 volt limit. This would lead to overcharging the battery. Lithium ion batteries do not like to be overcharged, they tend to overheat, swell up, catch fire or explode. (The new Boeing "Dreamliners" were grounded because of lithium battery fires.) Those of you who know might think that the battery pack itself usually has an internal circuit protector chip. A proper charging setup would have both monitoring in the charger AND a chip in the battery. This means your safeguards go from 2 to 1. This is assuming that GREENERY actually went to the expense of putting the chip in there. If not, your safeguards just went down to zero. What are the chances of this happening? Consider the risks. 1. The charging circuit is unfused and hooked directly into your wall socket. This means if there is a problem, the unit itself blows instead of the fuse. 2. Having the item delivered with a component loose does not speak well for attention to quality control, never mind safety. 3. It is very likely that the internal components are cheap and more prone to failure than a better built product. 4. A cranky lithium ion battery it something you don't want to mess around with. SUMMARY: It's cheap, but what do you want for 11 bucks? To be truthful, I like the design so much that I am now retrofitting it with a larger capacity battery pack and rewiring it to work with a proper external lithium-ion battery charger that will get it up to full capacity safely. Yes, I turned this potential fire bomb into a home project. This is fun if you know what you are doing. If not, you shouldn't go anywhere near this product.