I have a couple of these batteries in my junk drawer - MakerFocus 4pcs 3.7V 3000mAh Lithium Rechargeable Battery 1S 1C LiPo Battery with Protection Board. I want to use them in a project, but I need some help figuring out a charging circuit for them. Since they are fairly common, I thought others in this forum would have experience with them.
First, I can't find any information on the "Protection Board" in the title. The description on Amazon says:
Protection board with a MOS tube, over current protection 4.8-6A
MOS tube? I don't think there is really enough room in the battery for a vacuum tube...
The MakerFocus site says the same as above, but in another spot on the product page says:
Overcurrent Protection: 1.8-2.1A
which sounds more reasonable.
Second, I need to design a 5V UCBC charging circuit for these batteries. The MakerFocus site says:
Charging this battery to 4.25V at 0.2C constant current, then charge the battery at a constant voltage of 4.2V till it's charging current≤ 0.05C.
Any suggestions on chips or modules would be helpful.
Finally, I need to power an ESP32-S3 with one of these batteries. Do you recommend a linear regulator to step down the volatage to 3.3V or a buck converter to step up to 5V?
Since LiPOS are dangerous, you should be storing them at the Storage setting on a proper SkyRC balance charger.
As far as protection, it is a small PCB.
Do you plan on charging the battery under load or separate. If under load then the complete circuit is shown below and the forum thread with a LOT of info is at https://forum.arduino.cc/t/at-last-18650-charge-boost-module-with-load-sharing/1164462/5
If you want to use solar charging the circuit changes a bit with some solar specific components but I forget where the diagram is. If you need it let me know and I will ask the guy who knows.
I am not using any solar panels. Just a couple of ESP32s connected over WiFi to test some code for automatic MAC Address discovery and network mapping. A couple of switches and LEDs complete the project.
BTW, thanks for responding so fast. I was interrupted half-way through editing my original post. You did a great job reading my mind! Thanks again!
If your ESP32 boards have 3.3V regulators, it may be possible to feed the output of the charging circuit directly into the "5V" input of the regulator. Then you wouldn't need to add a regulator at all. You would need to test that however since the ESP32 board's regulator may have a high dropout voltage. If possible, try to identify the regulator and look up its datasheet.
Also, for USB-C, that schematic doesn't include the 5.1K pulldown resistors on the CC lines, so you would have to add those. However, some of the TP4056 modules are now featuring USB-C, and they should already have the pulldowns installed.
I don't know what their protection circuit is, but I think an "MOS tube" is just a mosfet. If so, then it could be the standard DW01 circuit.
Almost. VBUS should have a straight shot to the schottky diode. So you need to move R404, and eliminate R407. I've seen R407 in only one other circuit, and don't know why it's needed.
The 2.7V minimum input would be for output voltages lower than 3.3V, and in fact lower than 2.7V.
As for whether input voltage for that regulator needs to be a minimum of 4V, I would just say that it is a very low dropout regulator, with dropout voltage varying with the current draw. So you might experiment with applying battery power directly to the 5V input, and see what the battery voltage is when the circuit stops running properly. I should say that @jim-p and I have disagreed about this point repeatedly. He is the one with the credentials.
Am I correct is assuming that this TP4056 board from Amazon - will provide that same regulated 5V to the ESP32 as my modified schematic to include the MT3608?
There are many board versions with the ESP32S3.
The tiny Seeed XIAO ESP32S3 has a LiPo battery connector and built-in charger, so no other parts needed except for the battery. Limited number of pins though, but fine if you connect with I2C or SPI.
Leo..
No. The Amazon description is wrong. That's a basic TP4056 module which includes battery protection, but has no boost converter. So at most its output is 4.2V when charging the battery, and when not charging, you'll just get the battery voltage.
Well, it includes the charger and the boost converter, but no battery protection. Also, I'm not sure it has any provision for an on/off switch between the battery and the boost converter, as shown in your revised schematic, and which is something you should have.
You could get the TP4056 module with protection, and a separate MT3608 module. Then you would just need to add the schottky diode, the mosfet, the resistor, and the switch. And of course the battery.
Then use a charger without protection.
Not sure how two protection circuits in series will behave.
The board in post#15, charger without protection and boost converter, seems ok.
The board in post#13, protection and no boost converter, is not ok.
Leo..
