ESP32-C3 XIAO Battery Charging IC

Products & Technology XIAO
1

Does anyone know the IC used for for the battery charging circuit?
The schematic just labels it as U1 and does not give a part number.

I want to use a secondary 4.5V power supply (not a battery) to power the board when USB is not plugged in, so I planned on connecting it to the battery pads. This is higher than a battery’s typical voltage, so I just want to make sure it’s safe to do so. The 3.3V LDO regulator circuit looks like it would work with a 4.5V power supply, but I can’t confirm that the battery charging circuit won’t explode when 4.5V is applied to the battery voltage because I don’t know what IC it is.

Any help would be greatly appreciated.

2

Hi @melsh
The IC used for for the battery charging circuit(U1) is ETA4054

3

Do you know if it’s safe to simultaneously plug in the GND/5V pins and the USB to charge a lipo battery ?

4

On the Seeed Studio XIAO ESP32C3, it is generally safe to use both the USB connection and the 5V pin at the same time.

This includes:

  • having the USB cable plugged in, and

  • supplying 5V through the 5V pin.

You can do this while a LiPo battery is connected and charging.

The external 5V supply should be well regulated. It should also stay close to standard USB voltage, around 5V.

5

Since this connects the outputs of two 5V power sources, it could cause a malfunction depending on the type of power source connected. I do not recommend supplying power to both the USB and 5V pins at the same time.

1 Like
6

Hi there,

So , “NO” would be the correct answer. Generally or otherwise. Have a Look at the Schematic, you will see where two power paths and the potential for a conflict , source or SInk. so, NO. it is never advised and is not listed in the wiki or technical documentation any where, quite the contrary.

HTH
GL :slight_smile: PJ :v:

7

@PJ_Glasso If the power supply is regulated, still No?

8

If there is a way to prevent feed back from XIAO’s Pin 5V to USB 5V or vice versa then no :cross_mark:. Otherwise there could be an issue.

Since the USB 5V (voltage) can’t be controlled (depends on USB), the easiest way is to have the “regulated” 5V include a series diode/MosFET and be a lower voltage than the USB’s 5V (eg 4.5V - I have some USB hubs that can only supply 4.7V).

9

Hi there,

So , @grobasoz has it right..
Maybe if you use some Zener diode clamp type config, but it’s just not worth it technically IMO.

man , take a week off to bury my mom in PA. and the questions pile up, fazoul I got 38 emails..:grin:

GL :slight_smile: PJ :v: