ESP32-S2-DevKit-Lipo-USB

[findmyname]

Hello,

I have few dummy questions about battery for ESP32-S2-DevKit-Lipo-USB:

- What is battery connector on the board ? Is it JST ?
- What is ideal battery voltage ? > 3.3 V < 5 V ?

Any additional notes are welcome

Thx
BR

[LubOlimex]

- What is battery connector on the board ? Is it JST ?

Yes, it is two pin JST connector, but always be careful before attaching random battery - sometimes + and - are reversed!!!

I think the manufacturer's name is CI0102M1VT0-LF.

Use this as an example of compatible battery:

https://www.olimex.com/Products/Power/BATTERY-LIPO1400mAh/

- What is ideal battery voltage ? > 3.3 V < 5 V ?

5V is too much. The absolute voltage that the battery charger would provide is 4.242V. The battery charger is BL4054B - find its datasheet for exact values.

[findmyname]

Hi @LubOlimex,

Thanks a lot for the fast reply.
I was able to find all relevant information based on provided info (at least I believe in it ).

I have 2 more questions:
- Do you have any experience whether solar panel can be used / connected to the board as 2nd source of power or to recharge the battery ? (just high-level idea).
- Can I find somewhere info how to get battery capacity while in use ?

Thx
BR

[LubOlimex]

- Do you have any experience whether solar panel can be used / connected to the board as 2nd source of power or to recharge the battery ? (just high-level idea).

No experience. Can't recommend any product.

- Can I find somewhere info how to get battery capacity while in use ?

There is option provided. There is jumper that if you close you can find battery charge info on GPIO8, the jumper is called BAT_SENS_E1. To close it solder the pads together. Look at the schematic's top left corner:

https://github.com/OLIMEX/ESP32-S2-DevKit-LiPo/blob/main/HARDWARE/ESP32-S2-DevKit-Lipo-Rev.B1/ESP32-S2-DevKit-Lipo_Rev_B1.pdf

Above it you would notice another jumper, called PWR_SENS_E1 - if you close that one you would also have detection for when main power supply is missing on a GPIO (this can be used for some low power battery scenarios).

[findmyname]

> There is option provided. There is jumper that if you close you can find battery charge info on GPIO8, the jumper is called BAT_SENS_E1. To close it solder the pads together.

Neat. Is there any trade off when I solder them together ? or is it only about that I loose GPIO8 for application ?

> Above it you would notice another jumper, called PWR_SENS_E1 - if you close that one you would also have detection for when main power supply
Does main power supply means power via USB ? I can see that detection is on GPIO7 - is that correct ?

> this can be used for some low power battery scenarios
Something like backup battery in case of power outage or ?

P.S.: It would be useful to create some wiki page (or something like that) where we can collect knowledge, tips about the board. For example for me as not really electrical person it would be great addition.

Thanks a lot
BR

[LubOlimex]

Only losing GPIO8.

Yes, about power sensing - it would be available at GPIO7. The idea is that you would need to know that you might want to know if and when the USB power is missing, so that you can switch to lower power mode your board and code board, so that the battery lasts longer. Without GPIO7 you don't know when you lost USB power, the board would just operate at full force on the battery.

[findmyname]

Nice, can't wait to try it 

[findmyname]

Can you advise whether JST connector has positive lead on right side or left one ? (from front side).
I connected battery and USB to the board and it smoke out

I tested battery polarity before hand with custom circuit containing LED and resistor.
So far polarity of battery seems fine.

Photo: https://postimg.cc/1nkXm95z.

[LubOlimex]

Well, I did warn you few weeks ago to always be careful before attaching random battery - sometimes + and - are reversed!!! Looking at your picture basically you have caused a short-circuit - you have put a battery that has the + of battery to - minus of board charger and - of battery to + of board charger.

+ and - are printed at bottom of the board, under the JST connector...

[findmyname]

Hi @LubOlimex,

I did warn you few weeks ago to always be careful before attaching random battery - sometimes + and - are reversed!!!

Yes I know you did but i didn't expect that there is mismatch between connector polarity and board itself. No big issue I have more boards.

BR