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Simple circuit for Battery Status indication for 7.4v re-chargable battery?

MEERA

Jan 29, 2014
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For my MINI PROJECT I need to get an LED indication for full battery and low battery(if possible)

The circuit must be simple with components such as transistors,resistors..etc
 
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Arouse1973

Adam
Dec 18, 2013
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Hello.
Umm could you be a bit more specific. If you want people to help you then you need to give us a bit more of a clue. Like battery type, voltage, Amp hour rating.

What's with the weird typing?
Adam
 

(*steve*)

¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
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Jan 21, 2010
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You need to consider that pretty much each type of battery has a different way of detecting "full" and "low".

Since this is pretty clearly homework, I assume you are either told what sort of battery, or can choose for yourself.

If I were you, I'd pick lead acid or LiFePO4. Both have well understood and easily implemented measures of charge level.

LiFePO4 has an advantage over other Lithium technology that if you make a bad mistake you tend to get smoke rather than flame.

Once you've decided on your battery technology, you'll have to do some research into how these are charged. I assume you don't actually have to charge them, but just detect the charge level. This is pretty easy for the cells I have mentioned.

Note that temperature can affect things (especially for lead acid) but for the purposes of your homework you might be able to note, then ignore the effect, assuming that the ambient temperature is constant and reflects the battery temperature.
 

MEERA

Jan 29, 2014
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Details of the battery system

Thanks for ur intrest in my question
The details are as follows
7.4v 1000mAh (single battery)
Li-on battery (used in mobile phones)
 

(*steve*)

¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
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Jan 21, 2010
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OK, now you need to research how Li-Ion batteries are charged.

Are you trying to detect that the battery is fully charged or that charging should cease (there is a subtle difference)?

And what constitutes an empty battery?

Do you wish to consider the battery as a whole or look at the cells within the battery.

It might help if we knew more about your assignment.
 

MEERA

Jan 29, 2014
17
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This Li-on 7.4v 1000mah battery charges with 10v,500ma
It is a single battery as a whole
i need to detect full charge of the battery
It is fed to 5v voltage regulator (LM7805)
 

(*steve*)

¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
Moderator
Jan 21, 2010
25,510
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25,510
OK, now you need to research how Li-Ion batteries are charged.

Are you trying to detect that the battery is fully charged or that charging should cease (there is a subtle difference)?

And what constitutes an empty battery?

Do you wish to consider the battery as a whole or look at the cells within the battery?

It might help if we knew more about your assignment.

(I can use colours and bold too. But it doesn't change the fact that without you doing the research yourself, I'm not going to do your homework. Oh, and also you didn't manage to answer any of the questions)

 

Arouse1973

Adam
Dec 18, 2013
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OK, now you need to research how Li-Ion batteries are charged.

Are you trying to detect that the battery is fully charged or that charging should cease (there is a subtle difference)?

And what constitutes an empty battery?

Do you wish to consider the battery as a whole or look at the cells within the battery?

It might help if we knew more about your assignment.

(I can use colours and bold too. But it doesn't change the fact that without you doing the research yourself, I'm not going to do your homework. Oh, and also you didn't manage to answer any of the questions)


PMSL
Adam
 
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