The Li-ion 18650 for sale on the Internet: There are more false than legitimate

When I started acquiring Li-ion batteries 18650 back in 2012 to restore some packs, there were still no stores in Spain that had them and I started to import them through Chinese pages like DX.com, aliexpress, Ebay, etc.

Note: The reference "18650" refers to the shape and dimensions; 18 is the diameter in mm, 65 is length and 0 indicates the shape; in this case cylindrical.

At first I was confident and I trusted the ads in some extent, I knew the false capacities of some NI-MH before, where manufacturers also indicated many times more capacity than real, so I was prepared. I compared, and bought cheap, but not the cheapest, high capacity (announced) batteries, , and hoped that there would not be much difference.

This problem is very well explained in Energizes or Bateriasdelitio.net , which echo the deceptions of Chinese "smart" guys.

I was wrong. I came to ordering (ouch!) For 3 €/unit. 18 batteries "Fandy-FIRE", the "manufacturer" marked them as 3600 mAh capacity, when in fact they only had 800 or less! When they arrived the first thing that struck me was how little weighed; the larger capacity usually weigh 47 grams / unit, when these did not reach the 30 g / pc., although some manufacturers are "approaching" the weight of the good ones filling them with materials as diverse as flour!

In Depth: Lexman 9W LED bulb E27 230V 4000K 806 lm of Leroy Merlin

In my case gets 3 years warranty

LED bulbs are already flooding the domestic market, with options for almost every need.

We will analyze in detail a model that sells E27 Leroy Merlin with 3 years warranty brand Lexman  (non-publicizing, just to compare).

This bulb shines very well, with a more than acceptable theoretical efficiency of  90 lumens/W, perfect for replacing incandescent bulbs of 100W  (tested). 

His tone, a clear yellowish 4000º Kelvin, is suitable for everywhere in the house (although it is away from 5600K natural sunlight, colder), and a higher CRI of 80, enough.

If we break the glass we see that the controller gives 94V, feeding 33 LEDS 3528 series (which theoretically receive 2,84V and 0,27W each emitting 24 lm / ud), giving 806 lumens and 9W according to manufacturer (and although I can not measure it, seems to be true from its luminance):

The design to dissipate heat is of lightweight aluminum inside, which contacts the exterior part thermal plastic, that transfer worse the heat than aluminum, so it does not burn and can be touched, but it would be best if it were metal body such as lamps from Ikea, since the chip area after 6 minutes is at 43 ° C with 18ºC environment temp.:

With the (+ - 1 ° C) temperature sensor check infrared LEDs

and reaching 64 ° C! after half an hour, a temperature not very convenient for semiconductors. The manufacturer indicates a lifespan of 15,000 hours, but I hardly trust it, I recommend saving the invoice and not buying this bulbs because, if we use a lot, It will not reach the three years guaranteed!

Anyway, for € 6 per bulb, and for environments such as the bathroom where they are at most one hour on, they are more than recommended. For other uses, best to get better quality lamps.