Charger at 5v and device have charging IC / charger at 4.2v which is better?

[vinodstanur]

Hi,
I have seen many chinese products having lipo battery inside. Their charger is having the battery charging circuits (for constant current charging upto 4.2v).

Now there are few microchip chips (MCP73832) which will do the same function, it takes constant 5V input. This IC need to be very close to the battery since they don't want any voltage drop in the wire...

Now my question is, which method is more reliable for the battery life? [To keep charger at 5v and keeping MCP regulator in device or to design charger to 4.2v and constant current o/p]

 

[tpetar]

Cheaper Chinese chargers usually use IC TL431.

See examples:

Built-in battery charger Li-ion - new version TL431
**broken link removed**
**broken link removed**


Rechargeable Li-ion and Li-pol
**broken link removed**

Lithium based chargers also manage charging current and should monitor battery temperature and other parameters.


Best regards,
Peter

;-)

 

[sreepss]

Trickle charging method is very reliable charging methode for Li-Ion Batteries, But it Should not be overcharged!!!

 

[vinodstanur]

Cheaper Chinese chargers usually use IC TL431.

See examples:

Built-in battery charger Li-ion - new version TL431
**broken link removed**
**broken link removed**


Rechargeable Li-ion and Li-pol
**broken link removed**

Lithium based chargers also manage charging current and should monitor battery temperature and other parameters.


Best regards,
Peter

;-)

Hi,
But I want to know, if it is better to provide battery charging regulator IC in the device close to the battery or the chinese charger having 4.2v regulation in the charger itself.. I am feeling it will be better to use the MCP7832 chip inside the device and a 5v charger external.
What is ur opinion?

 

[tpetar]

MCP7832 is small IC I usually implement that IC in device with micro/mini USB connector, to support charging over USB.



Best regards,
Peter

 

[vinodstanur]

MCP7832 is small IC I usually implement that IC in device with micro/mini USB connector, to support charging over USB.



Best regards,
Peter

So what U will do, if U don't want to charge from USB, then U will go for a charger have built in charge regulation feature?

 

[tpetar]

So what U will do, if U don't want to charge from USB, then U will go for a charger have built in charge regulation feature?

I will do the same, I will put IC inside device, because IC require small space and various power sources can be used for charging, from mains adapters to car chargers,... If we have IC or charging regulator in mains adapter then charging is sticked to that adapter-charger, and this can be very dangerous if we forget that and use some 5V power source to supply device!


Best regards,
Peter

:wink:

 

[vinodstanur]

I will do the same, I will put IC inside device, because IC require small space and various power sources can be used for charging, from mains adapters to car chargers,... If we have IC or charging regulator in mains adapter then charging is sticked to that adapter-charger, and this can be very dangerous if we forget that and use some 5V power source to supply device!


Best regards,
Peter

:wink:

I have to put few LEDs in the charger to indicate the battery level. For that I am planning to use a small ATtiny microcontroller. I will take one wire from the device to the charger, it will be the +ve of the battery, will be connected to the adc of the 8 PIN attiny microcontroller.
What is ur opinion about this approach ? Any simpler approach in ur mind?

 

[tpetar]

I have to put few LEDs in the charger to indicate the battery level. For that I am planning to use a small ATtiny microcontroller. I will take one wire from the device to the charger, it will be the +ve of the battery, will be connected to the adc of the 8 PIN attiny microcontroller.
What is ur opinion about this approach ? Any simpler approach in ur mind?

Yes this is good, use SMD parts except LED diode. LED diode can be multicolored for better voltage showing.