Charging question

[Pregulla]

I have a generic TP4056 charging board. While charging the voltage goes up to 4.28v, but right after it terminates cell voltage is 4.16v. After a few minutes it restarts charging, then stops again. After few such cycles the cell gets to 4.2v and charging no longer restarts.
Is it safe to use this board?

[DanielM]

I have one also, works fine. I did not measure voltage on it.

[WarHawk-AVG]

hmm…odd, how hot is the chip on the board, if charging at 1A might want to glue a smallish heatsink to it, as for me…I solder on a 2.2K resistor on the RProg pin to limit charge current to ~500mA

HKJ did a test and found that it charges ok at 1A but gets hot and bit squiffy

What battery are you charging, and how do you have it connected to the battery to charge?

[Pregulla]

I’m testing it again now. Charging voltage is currently 4.20v, cell voltage out of the charger is 4.15v, the charger pulls 0.2A from USB port (based on usb tester). I can’t feel the chip being warmer than ambient temperature, I guess it’s few degrees higher, but not hot.

[HKJ]

@Pregulla

I have a generic TP4056 charging board. While charging the voltage goes up to 4.28v, but right after it terminates cell voltage is 4.16v. After a few minutes it restarts charging, then stops again. After few such cycles the cell gets to 4.2v and charging no longer restarts. Is it safe to use this board?

The chip will charge up to the full charge voltage, before it stops, with old batteries it might restart again, because the voltage drops.

The maximum voltage from the chip is 4.263 volt according to the datasheet, i.e. either you DMM is wrong or the chip is out of spec.

[WarHawk-AVG]

@Pregulla

I’m testing it again now. Charging voltage is currently 4.20v, cell voltage out of the charger is 4.15v, the charger pulls 0.2A from USB port (based on usb tester). I can’t feel the chip being warmer than ambient temperature, I guess it’s few degrees higher, but not hot.

Doing what it is supposed to do, CV (constant voltage 4.2vdc output) when you put a discharged battery the voltage will sag until the battery starts saturating on the charge.

You need to go ahead and push above 4.2vdc into the charger (4.8vdc-5vdc [standard USB voltage] nominal), it internally regulates it back down to 4.2vdc

Here is HKJ’s review

Review / Measurement: Charger module with TP4056 controller

Charger module with TP4056 controller [image] Click for larger picture This charger is a very small module for DIY people, it uses the TP4056 controller and standard configuration is with 1A charge current. It does not include any power supply or tray. It did not include any documentation either, just a couple of boards. The review is about a specific charger module, but any module with the TP4056 will have identical performance. [image] [image] I got it in an envelope with 5 cir…

[Pregulla]

The HJK review is of a charger based on Top Power IC with their logo, my board has generic TP4056 with no logo, I would not rely on it acting according to data sheet or same way as the board in the review.

From the review:

The charger will restart charging when the cell drops to 4.0 volt.
The charger will not restart after a power loss or battery insertion, except if the battery voltage is below 4.0 volt.
This chip uses 1/10 of the charge current as termination current.

My board restarts charging at about 4.15v and after power loss (if the voltage is under 4.2v). Before terminating it was pulling 0.15A from USB.

I guess restarting charging is indeed because of old cell, although other chargers and boards I had (i2, few millers, TP4056 board from FT) would not restart. Tried new cell and it wasn’t restarting.

Near termination the charger output is 4.28-4.29v on new cell as well (measured at board terminals), but the battery voltage after termination is 4.2v. Is it normal? Is it safe to use this board?

[Helios1 (Helios-)]

Yep, these “4056” clone chips don’t seem to be as good.