16Views0Replies

Author Options:

How do i make a 12v battery indicator with flashing leds when recharging Answered

Hi guys.

I have a 12v lead-acid battery and i want to make a circuit, which can show me state of charge of the battery with 5 (blue or white) leds. When the battery is in use, it should light up all 5 leds at 100%, 4 at 80%, 3 at 60%, 2 at 40% and 1 at 20%.

Now when the battery is flat and i want to charge it, i would like the leds to light up in order, as it gets recharged. Lets say it has 0% capacity left and i plug in the charger, the first led should start flashing/blinking. When the battery has charged to over 20%, the first led should turn solid and the second led should start flashing, indicating that the battery has now recharged somewhere in between 20-40%. This goes on until it has reached 100% and all leds should light up solid (no more flashing leds).

Furthermore i would like to add a switch, which can turn on/off the indicators, as they take unneccesary power from the battery. This switch should only be able to activate the leds when the battery is outputting power, as i want the battery to behave like i described when it is being recharged.

I have an example video of it, which is from the battery box of the Soundboks (go to 0:50 to see effect):
https://www.youtube.com/watch?v=rlY8B2dHYD4&t=50s

Is this something anyone can help me with?

Thank you in advance

Discussions