overcharge protection & charge meter for 6V battery

The overcharge protection is already built into your phone. There's no external access to the battery or this protection, thus no way to access the information needed to provide the indication you desire. [unless the RFI that is generated by the phone's charging circuit can, in some way, be interpreted to provide this information.]

Addendum: All an external phone "charger" provides is a source of 5Volts with enough current to power the charging process. If you want to do this with 6 volts, then the 7805 is the wrong choice as it's dropout voltage is around 2V which will drop that 6 Volts down to around 4 Volts. What you need is a Low Drop Out [LDO] regulator such as the TA48M05F.

you misunderstood my intention I want overcharge protection and charge meter for the external battery itself not for my phone.

"Sanyo eneloop" batteries are rechargeable

thanks for this valuable info

Ahh, sorry about that. Then you need to research "NiMH fast-charge management ICs" or "NiMH Battery Charge Contoller ICs" as well as a "Battery Level Indicator IC" Or in general, "Battery Management"

You can also change "IC" to "Circuit" for another set of results.

* http://www.element14.com/community/thread/4644

A useful site for battery principles and charging methods:

http://batteryuniversity.com/

Lithium Ion:

http://batteryuniversity.com/learn/article/charging_lithium_ion_batteries

Hello to all,
I decided to do small project but before noticed it, It became nightmare because of my immatureness.

Okay this was my small project. I wanted to build external battery for my mobile phone
(I know there are a lots off such devices on the market, but I wanted to get experience with this project)
I decided to go with 5x AA Sanyo eneloop batteries total voltage 6V (they are Ni-MH rechargable, each one 1.2v)

My phone accepts 5V on USB B plug.

For charging this batteries I will be using my phone charger through IC 7806 (which will step up 5v to 6v)

but for charging my phone from this device I will be using IC TA48M033F (which will step down from 6v to 5v)


problem which I have is I need schematics
1. overcharge protection for external battery itself .
and 2. charge meter for external battery itself [for this I have 5mm RGB LED I am thinking (red=low charge, green=okay charge, blue=good charge and white=perfect or overcharge) or (red=low charge, yellow=okay chage and white=good charge)].

Linear Technology has many many different battery charging solutions. This particular charger is a demo board already assembled and fully functional. It has two chargers, one that boost up say 5V to 6V, and another on that drops down say from 6V to 5V.

It does not need overcharge protection external because that is all built in when you select the battery type. It also has status indicators that tell you when the battery is charged. It doesn't have a ,"Gas Gage," per say, although they have functioning demo borads for that if you really want one.

The deal with this is that it is already designed & built, has schematics, part values the whole 9 yards.


http://www.linear.com/product/LTC3558

To add... when I researched this very thing a while back, I was unable to find an IC that did both battery fast-charge management AND battery charge level monitoring. There are ICs for each function, but I wasn't able to find a one-chip-does-all solution.

Please share whatever you found

Too long ago to recall