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Topic: But what do these flashing LEDs mean? (Read 1 time) previous topic - next topic

Nick Gammon

We've all probably got a few gadgets you plug in, to recharge. Cordless drills, electric toothbrushes, mobile phones, game console controllers, and so on.

But I was wondering if there is a standard for what the little LED that sometimes flashes, and sometimes changes colour, means?

I'm pretty sure that on some gadgets the LED flashes to show "I'm still charging" and then blinks steady to show "ready now".

But others glow steadily while charging, and then flash to say "done".

Is there any standard at all? Even a de-facto one? Because it's pretty annoying to find your gadget with its flashing LED and wonder "does that mean it is charged yet? or not?". Short of finding the User Manual. Where-ever that is.
Please post technical questions on the forum, not by personal message. Thanks!

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Flashing lights are OK on their own, but if you had a lot of units on charge  a " recharge area " on the desk, the flashing lights have an interferometer effect that can drive you mad.
I prefer red for charging and green for full.


AFAIK there's no standard, so you never know if the batteries are charged or charging. As for red/green, half the time I can't see the difference.

BTW, nice grey shirt you're wearing there Boffin.
Rob Gray aka the GRAYnomad www.robgray.com


Whoops,   forgot about the colour blindness !

Buzzers wouldnt work either 'cos I am half deaf !

Whats that lavender smell ?  oh the celphone must be charged :-)


One of my Canon chargers has a small graphic, something like this

_ _ _  50%
...    80%
____ charged

Ok that lost something in the translation, in other words slow flash is 50%, fast flash 80% and steady 100%.

I think that's a great solution and despite my drawing it's immediately clear when you look at the charger.

Whats that lavender smell ?

My missus has no sense of smell, try again, and please no comments about how fortunate that is for her :)

Rob Gray aka the GRAYnomad www.robgray.com


Dec 19, 2012, 10:54 am Last Edit: Dec 19, 2012, 10:56 am by Boffin1 Reason: 1
My missus has no sense of smell, try again,
mine dissapeared for 2 years, and while walking by the sea it suddenly came back, and the first thing I smelt was a fresh dog poo that had just been stepped in  :-(

Ok that lost something in the translation, in other words slow flash is 50%, fast flash 80% and steady 100%.

but if you had that with LEDs  you would get all sorts of patterns, at some time in infinity they would all flash the same !

I made a project about 7 years ago, with 2 chips ( before Arduino )  and 6 transistors, that could fade 10 strings of RGB LEDs at random through all the colours( they had crappy capacitors in the clock circuit so it was I guess random as the heat would never be the same through the box ?  )  

The colours could also be set manually with 3 pots, and the units could be cascaded and either synced, or all free running.

Each string could be wired differently - well 9 ? ways , so there were all sorts of combinations, but every few minutes, all 3 colours would be out for a second or so, and if you timed the interval, it was always a bit different.  I have a couple in the drawer,  I must connect one up again, it was very soothing.

If it had an arduino chip in it I would put it on playground !

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