Hi
I just made an modified version of LMIC for ESP32.
It handle deep sleep between TX (by saving state to RTC RAM)
It use ESP AES functions and RTC clock.
If you are interested the code is here : https://github.com/ngraziano/lmicesp32
I test it on Heltec board in EU868.
This seems to be a reaction to my post above, i forwarded it to Lilygo. That means my assumption battery has direct connection to 5V USB was validated by them.
Unfortunately another fatal design flaw and poor quality management seen at a chinese manufacturer…
I received same mail today.
This is really dangerous. If i would have left the board with battery and USB connected unattended, my flat would probably had burned down. And i used a small 3Wh battery only. That’s far less than e.g. a common 18650 cell…
I’ve designed a small snap fit case for the ttgo V2 1.6. Some rough edges that I will clean tomorrow and then I’ll put it on thingiverse.
good afternoon , i am trying to go down the ttgo v1 consume … in this moment i am in 8.7 ma ; i remove the leds license plate and the battery charger … someone Has anyone been able to lower this consumption?
It won’t be possible because of the board design. See this post on github and the entire thread for more information about this:
They are talking about the Heltec version, but the same principle should apply to the TTGO.
hi, in this moment i have a ttgo in 800 uA, i want to get down more; but the flash memory isn’t in sleep mode.
Thanks
How have you come to that power consumption? Very interested!
I’ve also got the TTGO ESP32 V2 1.6 unfortunately still can’t see the design on Thingiverse. Can you check if you’ve published publicly?
If you now following the link, you got the view off a nice case.
Be careful with connecting a battery, did you see the warnings above?
In the TTGO v1.6 design power from USB and battery runs over a diode (at least it should, when the did not accidently used a fuse). That means that we give about 0,1 Watt of power at this early point in heat, even before it arrives at any circuit… 
Hi all,
Been trying to use a 18650 rechargeable lithium ion battery with my TTGO ESP32 SX1276 microcontroller and not having much luck. TTGO does not seem to want to be powered by the battery.
From my understanding I thought that if you plug in the TTGO via micro USB it simply charged the battery and you are good to go, but it doesn’t seem to be the case with my testing.
Has anyone had any experience with powering this board using a battery? If so, could you please tell me what you had to do to get it working.
Thanks in advance.
Attached below are photos showing my setup for reference:
to lower the consumption it is necessary to review the hardware very well, to be able to lower the consumptions.
Which version of the board are you using? Beware:
My board isn’t the 1.6v-v2.1. It has no indication of the model on it. The link I supplied above shows a board identical to mine, excluding the OLED.
I’ll try charging the battery again to see if I didn’t charge it long enough. How long do I need to leave it for if I do so?
Just in case its one of the ‘faulty’ ones, I would not leave it at all.
Monitor the battery voltage with a multimeter, that will give you an indication whether its charging properly.
If it goes much above 4.2V then stop charging and\or run for the hills.
Sounds like a plan! Just interested… What are the operating voltages used for the TTGO when connected to the battery? I guess it’s 4.2V at a max, but how low can this drop to and still allow the board to operate?
Well, the ESP32 processor and LoRa device are 3.3V devices …
Very interesting testing I just did… it seems that the TTGO does not light up it’s LED when connected to battery. Anyone else had the same experience?
Now that is why I didn’t think it was working before, because I thought it was off.