Adding battery power to ESP32 project

[Stuee123]

Hi, I am making a bbq monitor with this baby

WT32-SC01 ESP32 LCD WiFi, 16MB Flash, 3.5" 480 x 320, Touch, ESP32-WROVER Sydney | eBay

Find many great new & used options and get the best deals for WT32-SC01 ESP32 LCD WiFi, 16MB Flash, 3.5" 480 x 320, Touch, ESP32-WROVER Sydney at the best online prices at eBay!

www.ebay.com.au

it says usb-c 5v/2a 5v/1a

I would like to add 3 18659 batteries to it to make it standalone and rechargable.
What would l need to do this and also how would i connect the batteries.. I will make a 3d printed case for it all in the end so size isn't an issue.

1 more thing, ill be setting so the screen is only showing temp number on screen when idle, then when touch it will show the proper screen like graphs etc. How long would 3 batteries last do you think. Im not asking for exact times just a ball park.

Cheers

 

[Lightium]

How do you expect to get 5 volts from 18650 batteries?

 

[Stuee123]

How do you expect to get 5 volts from 18650 batteries?

Why are you even responding? Clearly a regulator. This is why im asking the question the best way to do it and dont expect a smart arse response thanks!

 

[rjenkinsgb]

It appears the overall unit can take something like 2A or possibly more at 5V (see here) - the specs say supplies 2A and 1A:

ESP32 Development Board - WT32-SC01 with 3.5in 320x480 Multi-Touch capactive Screen, support Bluetooth & WiFi

WT32-SC01 is a development board with a visual touch screen. The board is equipped with self-developed GUI platform firmware and supports graphical drag-and-drop programming.

www.elecrow.com

As a pure guess, I'd estimate 300 - 600mA with the display on but low brightness and CPU mostly idle. That's 1.5 - 3W range.

Assuming you are using a good, efficient, switch mode regulator module, three 18650 cells (2.5AH each) would have a total capacity of roughly around 27WH. Call it 25WH to allow for 10% regulator losses.

Something like 8 - 16 hours probable operating time; but without knowing the exact operating currents, that could be off either way.


The cells could be in series or in parallel, depending if you use a boost regulator or buck regulator.

If you intend to charge them in the device rather than separately, go with parallel - it avoids the need for cell balancing and the whole thing charges as one large cell on a single cell charger.

Either way, you must have battery suitable battery protection board, connected between the cells and load.

For series cells that must also include a cell balance facility in the same board, unless you are using holders and taking the cells out to charge in a dedicated charger.

Note that the battery protection module (and balance section) is not a charge regulator, it is just to ensure the cells operate within a range where they are not likely to fail or explode.

ps. Any 18650 cells claimed to be 3.5 - 5AH (5000mAH) or more are 99% guaranteed to be fakes, much lower capacity and quite likely no more than around 2AH.

 

[Stuee123]

It appears the overall unit can take something like 2A or possibly more at 5V (see here) - the specs say supplies 2A and 1A:

ESP32 Development Board - WT32-SC01 with 3.5in 320x480 Multi-Touch capactive Screen, support Bluetooth & WiFi

WT32-SC01 is a development board with a visual touch screen. The board is equipped with self-developed GUI platform firmware and supports graphical drag-and-drop programming.

www.elecrow.com

As a pure guess, I'd estimate 300 - 600mA with the display on but low brightness and CPU mostly idle. That's 1.5 - 3W range.

Assuming you are using a good, efficient, switch mode regulator module, three 18650 cells (2.5AH each) would have a total capacity of roughly around 27WH. Call it 25WH to allow for 10% regulator losses.

Something like 8 - 16 hours probable operating time; but without knowing the exact operating currents, that could be off either way.


The cells could be in series or in parallel, depending if you use a boost regulator or buck regulator.

If you intend to charge them in the device rather than separately, go with parallel - it avoids the need for cell balancing and the whole thing charges as one large cell on a single cell charger.

Either way, you must have battery suitable battery protection board, connected between the cells and load.

For series cells that must also include a cell balance facility in the same board, unless you are using holders and taking the cells out to charge in a dedicated charger.

Note that the battery protection module (and balance section) is not a charge regulator, it is just to ensure the cells operate within a range where they are not likely to fail or explode.

ps. Any 18650 cells claimed to be 3.5 - 5AH (5000mAH) or more are 99% guaranteed to be fakes, much lower capacity and quite likely no more than around 2AH.

Thank you for that, the size of the board and the 3d print case, i think i can use 4 or 5 batteries.
So use a 5v 3a regulator and the separate 18650 protection / charger board too,

 

[rjenkinsgb]

One of these may be suitable for the power supply, with all the cells in parallel?
It combines a boost converter and USB charge input.

https://www.aliexpress.com/item/1005004995781158.html

It combines charge and protection etc.

From the description, you would need the type with the USB-A output port & take the device power from that, to be able to run it and charge (via USB-C) at the same time.