Hello everyone, I am working on my first ESP32 project using the XIAO ESP32S3 board, and I am trying to develop a project using a cell battery (CR2477). The project needs to take advantage of Wifi and BLE (that the board has). The project will not require Wifi and BLE on all the time, Wifi should become active only when a button is pressed, and BLE should only become active when traffic is sent from a cell phone.
My question is: is a single cell battery and a boost converter enough to reliably power the board? I am trying to use a cell battery instead of a rechargeable Lion just to make the project easier to maintain, since cell batteries are easy to replace than rechargeable ones.
Edit 1: I already have it built, and it works fine when the battery is in, and the ESP32 is connected to the laptop for debugging, BUT if I unplug the EST32 from the USBC it stops working so I believe it is either a Voltage or an Amperage problem
WiFi and BLE are the biggest consumers of power, so you will need either a 5V powerpack like an ANKER or a home-built 5V for USB connection. The other choice is to use the 3.3VIN pin with a 3.3V battery for a direct-to-pin connection. Remember, the highest non-damaging voltage on a 3.3 pin is 3.6V, so that rules out a direct connection to something like a LiFe 18650.
For a full explanation, type the following into a google search so that the AI gives the answer (too big to copy) how to power an esp32 from battery
Thank you all for the feeback! I am thinking about swapping that to a CR123A, since (I think) it would provide the Voltage and Amps I need. I was also thinking about a Lipo type but I have not seen any battery small enough (maybe 14430 Rechargeable Battery LiFePO4 3.2V?). This project is supposed to be a wearable, so it cant be too bulky or heavy ( also rechargeable makes things more complicated circuit wise, trying to keep it as simple as possible).
What are your thoughts about the batteries I suggested above?
The CR123 could work as long as you leave the radios off most of the time. Of course, a total power down (NOT sleep) during hours that the device is not needed will save the most, but that requires an extra chip to give you RTC functionality (with its own battery). There are also many less power-hungry boards than any of the esp32 family.
I am using ESP32S3, and I am under the impression that it has RTC capabilities without requiring an extra battery for it, but please correct me if I am wrong!!. Since my wearable is supposed to be fully inactive until a button is pressed, I SHOULD be able to have it in deep sleep, until I press my button ( and only there the Wifi should activate and most things would trigger).
What other boards can you suggest that have both Wifi and BLE capabilities, that are less power hungry than ESP32?
By definition a RTC needs power to keep it's clock running, otherwise it is NOT a RTC. I said POWER OFF, ZERO milliamps. Deep sleep for a dev board (I assume that is what you have) will likely (too lazy to look it up) still use microamps if not milliamps.
I will bow out as you have an approach you don't want to change.
Just using a dev board will use waaaaaaaay more power than a bare chip.
Be careful, the esp32 specs re current per sleep mode is for the BARE chip. A dev board has some amount of power-consuming add-ons. That is why LEDS are removed; even voltage regulators may be removed if the right battery can be found.
Also, remember the CR123 is only 3V, not 3.3V, and the MAX capacity is 1650mAh. Since it is wearable, a flat LiPo may be a better choice than the cylindrical CR123. The LiPo's come in a myriad of shapes, mostly fairly small and flat for the low-power types, BUT if this is for a commercial product, make sure you have a legal team and gobs of insurance since there is a non-zero possibility that a LiPo can explode or catch fire. I had an ANKER high-quality power pack start expanding to the point that the case was broken. Very scary stuff.
so I believe it is either a Voltage or an Amperage problem