Charging handheld device

[adeel.sid]

Hello
I am working to develop custom wireless charger for handheld device containing 5V li-poly battery (<1Ahr)
First I thought to develop both transmitter and receiver pair for wireless charging and then I realized that it may be done if I follow Qi standard. In that way, I can use available transmitter and just need to design receiver that will be part of circuit.
Can anyone guide me how to develop small receiver that will be compatible with wireless chargers available in market?
Following TI solution looks attractive but I couldnot decide because of my little experience
https://www.ti.com/lsds/ti/power-management/wireless-power-receiver-solutions-receiver.page

 

[adeel.sid]

Choice reduce to:
1. BQ51003 (charge current: .5A, output 5V)
2. BQ51013B (charge current: 1A, output 5V)
what is preferred for my case (.8Ahr batetry, 5V)
Please guide
Thank you

 

[Audioguru]

You need to learn about a Li-Po battery cell. Go to www.batteryuniversity.com .

One Li-Po cell is not 5V, instead it is 4.20V when fully charged and is 3.2V when discharged and it should be disconnected from its load. Therefore its voltage averages 3.7V.

If the charging voltage exceeds 4.20V then the battery cell might explode or catch on fire. A lithium battery is very dangerous if you do it wrong.
You need a charging circuit that is designed to charge a Li-Po cell.

 

[adeel.sid]

Thank your reply
Here is the battery I intend to use https://www.alibaba.com/product-detail/hot-sale-rechargeable-lipo-battery-5v_60051438009.html
Can you suggest another or Li-ion (I could change battery if wireless power is not supported)
Due to small device, dimension is the issue
Here is another on I am interested in: (not sure how to do it for my design)
https://www.adafruit.com/product/1901

 

[Audioguru]

Your link Alibaba is to a Chinese battery manufacturer. They list an 18650 Li-Po battery cell with a capacity of only 800mAh (most 18650 cells are 2500 to 3400mah) and a voltage of 5V (most charge to only 4.20V). It seems that a minimum order is for 100 of them.

Maybe they are fakes because their capacity is so low. Maybe they have a voltage stepup converter circuit inside.

Look at Wikipedia in Google for the battery cell. An 18650 Li-ion cell is commonly used in the battery for a laptop computer. I have many of them. It is a cylinder larger than an AA cell and is 18.6mm in diameter and is 65.2mm long. Some of them have a protection circuit inside to prevent an explosion or a fire if they are charged or discharged wrong. Another Chinese manufacturer sells a fake protection circuit that looks identical to a real protection circuit.