Battery charge indicator

MrNaz

Enlightened
Joined
Jul 20, 2006
Messages
244
Location
Melbourne, Australia
I would like to build my light with a battery charge indicator.

I could either do a series of LEDs (3 lit = full, 2 = medium and 1 = low) or colour coded (green = full, amber = mid and red = low), but I don't know what to use to do it. I would like to use extremely low current LEDs, say 5mA so it could be permanently on, with a low voltage cutoff to prevent long-term storage from totally depleting the battery.

Alternatively, I could make the indicator only active when the light is switched on. That would prevent the light from being empty when taken out of the cupboard. Either would be fine.

Another option would be to make the indicator only active for a short time after the light was turned off, but this would require some programming.

I have no idea what electronics to use to achieve this. Anybody have any suggestions on how to go about starting the design on this circuit? Where would I go to have the necessary programming of a board done?
 

revolver

Newly Enlightened
Joined
May 28, 2011
Messages
10
Sorry for the necro,

Did you ever find any more information on this? I was pondering this very question the other day and wondering what would be necessary in the design of a circuit to accomplish this. I was thinking perhaps a filed-down RGB LED could serve well as the indicator light, and maybe a flash every five seconds to use as a locator.
 

lucca brassi

Enlightened
Joined
Feb 1, 2008
Messages
889
Location
US
something like that http://www.instructables.com/answers/Simple-battery-charge-level-indicator/

simple way is with zener diodes and resistors , zeners you have in range from ww.farnell.com , so just pick wanted walue (if you want drop of 0,65V you can use ordinary diode )

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