[Tade0]

The other day my bicycle light gave out, so I took it apart - was not the most expensive option, but also not the cheapest.

It was advertised as having a 2600mAh battery, but when I opened it up, inside there was a 1700mAh cell. Also no sign of purported weatherproofing, as the lens was not even glued in.

I have a 2000mAh cell in the same form factor (approximately 500Wh/l, so believable) on its way from China, which makes me wonder how did they come up with that 2600mAh figure.

[namero999]

Because more is better. Seriously, the game they play is at this point ludicrous. I saw 18650 cell being advertised through the years as 2500mAh, to 3500mAh (still reasonable/credible), then suppliers started to one-up each other and you could see 5000mAh, 9000mAh, 9999mAh up to, I kid you not, 1.000.000mAh. If I had no clue, of course I would by the 1KAh single cell XD

[pixl97]

Flashlights are a good example of this too. "1 million lumens", like is that mini flashlight filled with plutonium?

[Hackbraten]

I wonder when they're finally going to one-up each other with the 18650 model number itself? Make it 18660, 19650 or 18650000!

Anecdote: back in 2004, a friend brought home a cheap digital audio player from her vacation to China. IIRC, it said on the front panel that it could play back MP3, MP4, and MP5.

[LargoLasskhyfv]

That's a real thing, there: https://docs.fileformat.com/video/mp5/

[Hackbraten]

It’s still bogus and not a real file format. Just MP4 files renamed into MP5.

[Rebelgecko]

For whatever reason, the lies about specs are particularly egregious for lights. Slopmarts like Amazon and AliExpress happily advertise 50,000 lumen flashlights (which would probably melt after a few seconds if they actually operated at that level)

[Tade0]

Indeed. This light is advertised as having a:

-2600mAh battery (9Wh)

-500 lumen light intensity

-5W LED

-4h battery life at constant illumination setting and this is the shortest time listed.

I now know that the battery is much smaller (6Wh) and 500lm is believable for a 5W LED but it's most certainly not this bright at any appreciable duty cycle. During those 4h it has to be pulling 1.5W at most.

It's funny how most of those parameters are not false per se, but at the same time create a false image of the device's capabilities.

[layer8]

> how did they come up with that 2600mAh figure.

The same capacity corresponds to different mAh at different voltages, maybe they are playing games with that.

[antisthenes]

AKA lying. No need to steelman dishonest small-time crooks and marketers from China.

Also, it's not the voltage, but over-current that reduces overall produced energy.

Typically the mAh is listed at some standard discharge rate, unless the cell is specifically advertised as a high-current draw cell. But either way an honest supplier will provide the draw/capacity table for you, rather than cherry pick the best one.