If I understand correctly, this XIAO can recharge batteries through the VIN, right ?
1- In this case does it have to be 5V rechargeable batteries ? Or can I use 3V 18650 ?
2- Any super reliable battery you would recommend for this XIAO ? I need 800-1000ma . Should I use camera batteries ?
3- Any way to use a rechargeable magnet/induction plug on the XIAO ?
For XIAO nRF52840 has a dedicated battery charger BQ25100 for the BAT+ and BAT- pin, which could used for charging 1 cell Li-Ion/Li-Polymer battery.
Q1: It support to charge 1 cell Li-Ion/Li-Polymer battery which the Battery charge voltage (Max) is 4.2V
For Q2 and Q3 I do not understand what your are looking for.
Q2: You have mentioned 800-1000ma current rating for what is purpose and usage?
Q3: Use a rechargeable magnet/induction plug on the XIAO for what is purpose and usage? is it for supplying power to XIAO?
Please check the datasheet of the bq25100 chapter 7 Specifications, it listed out the ratings about the charging chip.
Battery Connection. System Load may be connected.
The bq2510x has a single power output that charges
the battery. A system load can be placed in parallel with the battery as long as the average system load
does not keep the battery from charging fully during
the 10 hour safety timer.
So, it’s probably connected to the 5V pin too.
That’s how the battery must power the Seeed Studio XIAO when it’s not charging.
That must look like this
I’m looking for the schema that will show me that information.
Any idea where I could find this ?
So if you connect a battery to 5V pin (VIN),
and plug the USB, the battery will be charged directly by the USB 5V and not through the charger
because the USB connection will make the MOSFET non conductive
and therefore, there won’t be a connection with VBAT.
Thanks for the clarification.
I mistook VIN for the 5V path.
If a battery is connected to 5V (I’ve seen some people doing that on some video),
if the USB is plugged,
the device will actually draw power from whatever has higher voltage.
If you use a 3.7V battery, the device will draw power from USB and the battery won’t discharge.
But yes a diode would be a good advise,
to prevent damage to the battery in case it’s not a rechargeable battery
or even if it’s a rechargeable battery because there would be no connection to the charger controller.
So, I guess bottom line is that a rechargeable battery should be connected to Bat+ only
and a non rechargeable battery could be connected to 5V pin and adding a diode.
You dont need a 18650 to get 1000mA out, it exist flats one which should be much smaller.
One parameter which is important is the C-rate and how much peak current you need. Generaly for a 1000mAH battery you can get 1000mA peak load and charge it at max 1000mA (to simplify). But for drone application you can found battery with 20C discharge current (but price is not the same!).
I am scratching my head, having little knowledge in electronics but I would like to learn ( almost 60 years old, hopefully not too late…).
First of all, thank you so much guys for your help.
I am in love with tiny Seeeduino and I would like to connect a 5v 300ma DC motor ( a little windmill educational animation ), AND a rechargeable battery…
I believe 300ma is a lot and certainly too much for the Seeeduino.
=> I would like NOT to use the expansion board but straight solder cables to the Seeduino
=> Can I get 5V from the Seeeduino with a 3.7V rechargeable battery connected to the 3.7V port ?
=> Would you suggest a simple way to connect the 3.7v battery, the Seeeduino and the 5V motor without frying the Seeeduino ?
=> I am getting lost now at how I can recharge that 3.7 battery without the expansion board