Li-ion battery charger

[Winnie Raghu]

Hi

My project is to charge Li-ion battery with super lift Luo converter. But when i connected battery in simulation circuit,my output voltage decreased from 36V to 19.8V. So i could charge only 19.8V battery. Can anyone tell me the reason ?

 

[tushki7]

Greetings,
Post your Circuit!

Useful link : https://www.ti.com/product/bq24610

 

[Mithun_K_Das]

Charging Li-ion battery is not as usual battery charging system. So you need some extra care. To charge Li-ion, the charger should charge the battery in 3 steps.
1. Pre-charging
2. Constant Current charging
3. Constant Voltage charging.

1. Pre-Charging:
In this mode, battery will be charged with few mA for around 3/4 min.
2. CC Charging:
In this mode battery will be charged in a constant current such as 1A.
3. CV mode:
in this mode, Current is not fixed, but the voltage is.

 

[Winnie Raghu]

Charging Li-ion battery is not as usual battery charging system. So you need some extra care. To charge Li-ion, the charger should charge the battery in 3 steps.
1. Pre-charging
2. Constant Current charging
3. Constant Voltage charging.

1. Pre-Charging:
In this mode, battery will be charged with few mA for around 3/4 min.
2. CC Charging:
In this mode battery will be charged in a constant current such as 1A.
3. CV mode:
in this mode, Current is not fixed, but the voltage is.

I am considering charging state from 40% only. So it will start from CC state only. My converter is Super lift luo convereter.

 

[Mithun_K_Das]

be careful to maintain the battery voltage. it should not exceed the higher limit. a 3.7V battery have a higher limit of 4.2V. Higher limit must be less than +/- 0.02V.

 

[Winnie Raghu]

Yes.i adopted a CCCV algorithm which wont overcharge the battery. But my real problem is efficiency of converter has decreased when battery load has connected.Anybody implemented boost converter for battery charging?not only Li-Ion any battery.