can this be done? P.S. Q

[phorhas]

Hi, I'm a first timer here...

I have a question about a power supply/batt, charger I need to build. I'm designing an amplifier that uses a Lithium based pack (3 cells) for portable use. now, I want it to have a charger that also functions as the primary power supply when I'm indoors, but I don't want to have to disconnect the battary pack every time. can this be done?
If I'm not mistaken, leaving a battey in a somewhat perminant connection to a chrger/PS ruins the battary.

can this be done?


Dan.

 

[VVV]

Of course it can be done.
Do you have a charger? Is it an "intelligent" one? Or do you need to build the charger, too?

 

[phorhas]

Well, I can get whatever I should need... but what do I need?

I'm really new to this battery field and feel a bit like searching in te dark. so is there a block diagram or basic building blocks for the kind of charger/P.S I'm looking for?


Regards,
Dan.

 

[VVV]

Take a look at this part from TI https://focus.ti.com/docs/prod/folders/print/bq24032a.html

There are other chips out there, but this one seems to do what you want.
You can go to Linear Technology or Maxim websites, and search for other parts.

 

[phorhas]

Thank you.

I failed to mention that I plan on using 3 cells in series. What should I do if want to design a charger that will not ruin the cells - when it'll be always constantly connected?

 

[Slayerza]

AFAIK the IC that are available properly isolate the bateries from the rest of the circuit. Some also handles the charging until the batteries are charged and then performs the isolation.

 

[phorhas]

and then it supplies the circuit's power - which apon disconnection the batteries would supply?