XIAO Overheating when using usb power and battery power

Products & Technology XIAO
#1

Hello,

I noticed that if I hook up 3v (2 packs in parallel of 2 double A batteries wired in series) and also hook up the USB line my XIAO gets really hot and one of the LEDs will blink rapidly. I have to unplug everything and wait a bit before using it again. I have the battery + wired to 5V and the battery - wired to gnd. Is this configuration not supported? Or have I likely done something wrong? I also noticed that if I hook up a serial line to TX and RX, and connect the ground of the serial adapter to the XIAO the board powers on. I feel like this shouldn’t happen. :confused:

Any guidance would be greatly appreciated.

#2

Hi
@kkirbatski Are you connecting two batteries in parallel and connecting the positive and negative poles to the power pin of xiao’s GPIO and ground pin? If you use the GPIO pin to power it up, voltage input connected to general I/O pins may cause chip damage if it’ higher than 3.3V.

#3

Hi, if you know, it is possible to connect a 3.7v Lipo battery to the 5v of the seeeduino and connect at the same time a cable to the usb port to program it without disconnect the battery?

#4

This will not affect, you can connect to the computer while connected to the power source.

#5

If connect a 3.7V Lipo battery to the 5V pin of XIAO and connect XIAO to USB, isn’t it dangerous because a Lipo battery is charged from USB 5V without current limit?

#6

It is not dangerous*******************

#7

According to the circuit diagram, it will be connected to
VBUS(USB 5V) ----> D4 ----> 5Vpin ----> 3.7V Lipo.
Isn’t it overcharged even if VBUS (USB 5V) is directly connected to the 3.7V Lipo battery?

edit:
According to the USB standard, the power supply voltage range is up to 5.25V.
The voltage drop of diode D4 is Typ 480 mV in the data sheet.
The 3.7V Lipo, which is generally considered to be charged at 4.4V, is charged at 4.77V. Is this okay?

#8

If this is the case, you need to connect a power management module between the lithium battery and XIAO to prevent the overcharge of the lithium battery from damaging XIAO.

#9

XIAO_PB_BAT
XIAO_PB_BAT778Ă—316 80.6 KB

Hi, again, I don’t know if I didn’t explain myself well before or if my English is not very good. What I want to know is if I connect the XIAO with a battery as the picture shows, could I connect the USB-C at the same time to program it without disconnecting the battery and the powerboost?.

In the event that I cannot do it with the connection shown in the figure, what other option do I have to program it the XIAO without disconnecting the battery? I hope I have explained it well, and thanks for your answers.

#10

I understand that XIAO can be connected to the battery to upload programs.

#11

hi Citric, have you tried it? I would like to be sure, it is the only XIAO I have and I would not want to damage it

#12

Yes, there is no problem with that.

1 Like
#13

Thanks for the answer, I’ll try it today. :pray: :pray: :pray:

#14

Hey guys, I have the similar problem.

I connected a Lipo to BAT+ and BAT- on XIAO.
Then I connected the XIAO to my computer using USB-C, but it didn’t seem to be charging the battery at all.

One test I have done was disconnecting the Lipo and powering the XIAO with USB-C only. I tested the voltage and current between BAT+ and BAT-. The results I have is 2.38V and ~15mA. is it normal?

Another thing is, the XIAO got super hot, even after I disconnected the lipo battery from it.

Appreciate it if you guys can provide me with ideas.

#15

Hi Yi_Zheng,
A little more information might give us some ideas.
1.What is your XIAO? nRF52840 or ESP32C3 or ?
2.What is your battery? Is it 3.7V?
3.Can the battery be charged with another charger?
4.What is the voltage of the battery before connecting it to XIAO?
5.What is the voltage at the battery terminal when connected to XIAO and charging via USB?

The results I have is 2.38V and ~15mA. is it normal?

How did you measure the current 15 mA?
What measuring instrument did you use?
Where did you connect the probe?

#16

Hi msfujino,

I just found that the battery is totally dead now…

To answer your questions:

  1. XIAO BLE Sense nRF52840
  2. It is a 3.7V Lipo battery
  3. Haven’t tried yet
  4. Now, the battery is totally dead … It outputs Nothing now…
  5. Same, ~2.38V

As for the current, I was using a multimeter. Probes went to BAT+ and BAT-.

Thanks for your help.

Yi

#17

Applying an ammeter to BAT+ and BAT- may short the battery terminals with the ammeter, destroying XIAO and the ammeter.

#18

and what ever you do :astonished: ,DO not Hook Up Battery BACKWORDS.
Xiao Gets “VERY HOT” especially if the USBC is plugged in. It will still work but won’t ever charge another battery again. Don’t ask how I have come by this knowledge :wink:
specifically a Xiao BLE Sense , formerly know as the “Xiao BLE Nrf52840 Sense”
I still use it but it doesn’t charge batteries anymore.
HTH
GL :-p

#19

I’m curious why someone would use an outside charger for the lipo battery when the Xiao has it built in to charge from the USBC? I find the internal design to be very good, not needing any additional circuitry. I’m using both the Xiao C3 and the Nrf52840 Sense with the appropriate Lipo battery.

#20

Hi mt33326,
This post was about XIAO_SAMD21 which does not have charging capability until #11. Thus an external charger was discussed.
From #12 the topic has changed to the charging issue of XIAO_nRF52840, which has charging capability.