Hi, does a Xiao BLE powered from LiPo have some protection to avoid overdischarging the LiPo and damage it ? Does it shutdown if low LiPo voltage is detected ? in this case wich is the minimum voltage allowed to power Xiao ? Thanks
A quick scan of the WIKI shows a “bq2510x” Battery charging chip. Further The TI data sheet shows all the pertinent info , But short answer is YES.
HTH
GL :-p
Hi Leo,
Mabey you can still download the schematics at the bottom of this Japanese website.
According to the schematic, the battery is protected against overcharging when charging (4.2V). I do not see any circuitry to protect it when discharging. I think the discharge will not stop until the battery voltage drops to the point where the MPU cannot operate (2V?).
Thank you for reply to all. Indeed I didn’t find any note on the datasheet about an overdischarging protection circuit for the Lipo. Could it discharge until the battery is damaged and MPU stops to operate ? A technical answer from engineer is welcome ……
My idea is that read the battery voltage and issue a warning before over-discharging (e.g. below 3.4V).
yes but a warning couldn’t be seen. Anyway this is the solution if there isn’t a protection for the LiPo.
Hmm, Well when I read the Data-sheet (Page 5) Section 7.5 Electrical Characteristics
It’s the First Item on the list of Parameters.
UVLO Undervoltage lock-out exit I’ll let you read the whole data-sheet. (teach a man to fish)…
Further for our folks here Google has it at: UVLO search
Nigel Smith
ABSTRACT
Many integrated circuits include an undervoltage lockout (UVLO) function to disable the device at low
supply voltages. Below the minimum supply voltage the function and performance of a device may be
undefined, making it impossible to predict system behavior. This application note explains how to correctly
understand the undervoltage lockout specification in the data sheets of TI’s power products.
"
I let you dive in for the specific’s short answer is YES Range is LOW3.15 TYP.3.3 MAX3.45 DC volts. 
HTH
GL :-p
Hi PJ_Glasso,
I suspect that UVLO disable the regulator chip itself if the IN pin is below that values, not the MCU, this is explained in the datasheet. So it goes in UVLO if detects USB voltage low. Looking at the datasheet and schematic, the battery is directly connected to MCU ( and also to the regulator ) so the regulator cannot shutdown the MCU directly. I could be wrong as I am not an engineer …
Correct However Who knows what seeed has done under the hood connection wise, So all of my test revealed it shuts down and only retries charging if you disconnect and reconnect a dead or low battery each time. But on a whole it works very well going on well over 6 months.
"8.4.1 Power-Down or Undervoltage Lockout (UVLO)
The bq2510x family is in power down mode if the IN pin voltage is less than UVLO. The part is considered
“dead” and all the pins are high impedance. Once the IN voltage rises above the UVLO threshold the IC will
enter Sleep Mode or Active mode depending on the OUT pin (battery) voltage.
"
HTH
GL. 
On the batteries we sell, the protection circuit is soldered onto the battery and then taped into the little cavity at the top of the battery . This is very common for lipoly cells. If you don’t see any taped circuit board, the cell may be ‘raw’ - these raw cells are not protected.
