Thread Starter


Joined Oct 25, 2011
I have to design a clock or you can say an auto timer which will have to start when my 12 volts battery charger started and ends when the battery is fully charged, i have no idea how to do this.Please do help me


Joined Apr 5, 2008

I moved your post over here as you posted in the feedback forum:

Feedback and Suggestions Forum for providing feedback and suggestions about All About Circuits, including corrections to the e-book. This forum is not for getting help with technical questions.
Is this a homework / school project?



Joined Nov 12, 2008
Welcome to ACC! Are you a member of ASME (American Society of Mechanical Engineers) or does that stand for something else?

As Bertus asked, first question is, what is this for? Based on your name and project description, I'd venture to guess this is for a school project revolving around a formula or standard automotive car. If so, we can help as long as this does not modify or go into said vehicle.

Second, does your circuit need to start and stop a battery charger or just monitor it and measure the length of time it took to charge the battery?

Third, what is the make and model of the battery charger in question?


Joined Oct 22, 2011
call me crazy but shouldn't you be able to do this with a current monitor, a voltage monitor and a comparitor?

current monitor would tell you if you're charging and the v-sense would tell you if you've hit max charge?

...on second thought are the current monitors directional or not?

I'm thinking something along the lines as a li-po charging circuit. Usually there's a few of those in the datasheets for a current monitor
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