24V battery charge indicator with external LEDs

Hello guys,

First of all thank you for reading my post.

I am aiming to build a battery charge indicator with external LEDs that pulse red when charging and then switch to a solid state of green when charging is complete.

Any help or direction would be greatly appreciated.



What is your reference for the ‘charged’ state? Terminal voltage or charging current? There are several solutions & methods - often tied to the particular cell chemistry you’re planning to use. (Don’t mix them up or you may burn your house down!)

Try google - there are single chip solutions for charge monitoring and/or control. AnRduino for this is overkill (and requires additional parts) unless it has to do something else as well.

Definitely google. Keep in mind that charging voltage is typically higher than the battery's static state and that just because you see a specific voltage via DMM or analog input, that doesn't mean the battery is charged.

You will most likely have to use some sort of reference load and check for voltage drop when that load is supplied for X amount of time.

Or another way (not nearly as reliable) time how long it takes for a dead battery to charge and set up a timer. Like a car charger uses timers for different amp settings.

I'm just a hobbiest.

What type of battery? What is it that is doing the charging? How can you tell when it is actually charging? How can you tell when the charge is complete?

If you can answer those then the rest will probably be quite simple.