I found this lithium battery at home and would like to be able to charge it.
What circuit do I need to interface/connect a classic 5V-2A phone charger to the battery?


I would like to know if there are certain components (such as this TP4056) that, carefully chosen and with added circuitry, can charge my lithium cell

 

Do you want to build or buy the circuit?

 

Do you want to build or buy the circuit?

If you would like to link me some already made modules, gladly. I'll definitely buy one.
But I'd still like to know about how to do it. Some advice on what components are needed and how to get started. I would like to make the schematic and then print the pcb

 

It’s a good thing you asked before connecting the battery to a “phone charger.” They are not chargers, they are 5V power supplies. The charger is inside the phone. The result of connecting it directly to the battery could easily have been a fire or even explosion, depending in how much current it could supply.

A lithium battery charger is not for beginners. Even the experts at Apple and Samsung have built chargers into phones that caused fires.

 

Do you want to build or buy the circuit?

I know the TP4056, I follow its "typical application" in the datasheet.



But some things I do not understand, for example in the datasheet is written:
"The charge voltage is
fixed at 4.2V" but my battery is 3.7V .. is this a problem?

@BobTPH in fact, I would like to know if there are certain components (such as this TP4056) that, carefully chosen and with added circuitry, can charge my lithium cell

 

"The charge voltage is
fixed at 4.2V" but my battery is 3.7V .. is this a problem?

No.
3.7V is the nominal voltage.
The battery fully-charged voltage is 4.2V

 

I follow its "typical application" in the datasheet.

If your battery doesn't have the NTC temperature sensor built in that goes to pin 1, then you will need to buy the appropriate one and tape it to the side of the battery.
That prevents overcharging of the battery as it heats up during charging, which otherwise could cause a nasty battery explosion and/or fire.

 

If your battery doesn't have the NTC temperature sensor built in that goes to pin 1, then you will need to buy the appropriate one and tape it to the side of the battery.
That prevents overcharging of the battery as it heats up during charging, which otherwise could cause a nasty battery explosion and/or fire.

"the appropriate one"
How do I know which one is appropriate? In the TP4056 there is TEMP -0.3V～10V .. so I guess I have to use an NTC that gives me a voltage in that range. Am I wrong? Any other conditions I missed?

I have this NTC at home (datasheet attached), I don't know if I can use it because no voltage values are given in thr datasheet, I should test it (in series with a resistor) and vary its temperature 'simulating' what the battery might reach ... and measure the voltage at its ends.

 

For crying out loud, just buy a charger. That wheel has already been invented. They're very inexpensive and widely available. They have the plug, an LED, the spring-loaded contacts and everything.

If you can use a flashlight that uses that size cell, search for that. Many of them come with a charger and it's an inexpensive way to acquire both.

If you want to retain those leads, that's a different challenge. It looks to me like there could even be a thermal sensor involved there. Can you tell? Or is it just wires to each pole of the battery?

 

Mini USB TP4056 1A Lipo Battery Charging Board Charger Module AU Stock. These are cheap just search E bay, ihave used several of them & they do the job for me.

 

I like that one because it includes the 0.4 ohm resistor that reduces heating in the '4056, but it doesn't included the protection IC and MOSFET that some other versions do. With the other kind, I've cut a trace and added a small resistor. Otherwise, the '4056 gets uncomfortably hot.

 

How do I know which one is appropriate?

Don't know.
The data sheet gives no indication of what it should be.

 

Mini USB TP4056 1A Lipo Battery Charging Board Charger Module AU Stock. These are cheap just search E bay, ihave used several of them & they do the job for me.View attachment 292961

Hi!
Few questions:

1) I did not understand the purpose of the mini-usb.

2) the TP4056 has the option of using the TEMP pin as a 'negative feedback' where it reads the voltage of an NTC to avoid overheating or similar damage. Is it mandatory to use that pin? And above all, in the module in your photo I don't see where you could connect any pin coming from the NTC .. okey there is the TEMP pin of the TP4056 in its package .. but it doesn't seem to be connected to a female connector or anything like that to connect the wire coming from the NTC

 

Those modules dont use the temp sensing feature. Ive been using them for about 3 years now to charge my cells with no problems. For power i am just using 5V 1A plug pack.

 

The temperature sensor likely doesn't need to be used since at a 1A charging current, the battery is not likely to overheat.

 

The Rprog on that board appears to be 221 = 220ohm, but the datasheet shows values 1k2 - 10k, being 1A - 130mA. A 222 (2.2k) would be 500mA, or a 22B (1.65k) for 700mA would make more sense, though charging a 2000mAH cell at 1A (0.5C) should be fairly safe if the cell is undamaged and of a reasonable quality.

 

Pin 1 Temp is grounded on the circuit board.

 

This is a slightly different board with the same chip & no temp sensing, just P1 grounded. When the cell is fully charged the blue led lights up & charge stops. The cell is a 2Ah.

 

This is a slightly different board with the same chip & no temp sensing, just P1 grounded. When the cell is fully charged the blue led lights up & charge stops. The cell is a 2Ah.View attachment 293065View attachment 293066View attachment 293067

Hi!

The circuit in the photos you attached is the TP4056 module from your #10 post ??

 

The one in the photos is a slightly different board. It has battery protection which i am not using as its for if its fitted to a device internaly & i am only useing it as a charger only, & it has the same TP4056 charger chip. It was just at the time that board was all i could get for the same price. For charging only i am using the out neg & pos connections.