ESP8266 Community Forum

- Thu Aug 27, 2015 10:31 am #27173 Hi! I need a small power supply for my project. It's not some sensor to be on 24/7, but the kind of device to be used for 1-3 hours at most. I tried connecting 2 AAA batteries to produce 3 volts. It worked well with ESP-01, but for ESP-07 it wasn't enough. What possible solutions are there?
I thought it would be cool to use some kind of rechargeable battery like the ones in mobile phones. But I don't know if there are any to produce 3.3 volts. Other options: connect 4 AAAs to produce 6V and then use a voltage divider to lower it down to 3.3, or connect them 2 blocks of 2 AAA batteries parallelly. But I still don't know what to choose. What are your thoughts? Ebay links highly appreciated, thanks

- Thu Aug 27, 2015 4:45 pm #27196 Hi Alex, lots of options but realy need more detail as to what your intened application. 1 to 3 hours of WiFi @ 250mA is very different to 1 to 3 hours monitoring something @ 20mA, then sending the collected data in a single 20 second WiFi burst @ 250mA.

- Fri Aug 28, 2015 6:00 am #27222 A possible solution, based on a : 18650 Li-Ion rechargeable Cell + charging / monitoring circuit

ESP8266 MPDMv4 AC MAINS Dimmer Home: http://esp8266-projects.com/2016/04/mpdmv4-mains-dimmerswitch-html/
Available on Tindie: https://www.tindie.com/products/nEXT_EVO1/universal-ac-mains-dimmer-mpdmv41/

- Sat Aug 29, 2015 1:56 pm #27347 I think you should try again with the AAA cells. There shouldn't be any difference between the power consumption of an ESP-01 and an ESP-07 so its odd that your ESP-07 didn't work.

I've run ESP-07s and ESP-12s off AAA's fine, and using two AA and AAA batteries seems about the easiest and cheapest power supply choice. Just to confirm here's one running off a couple of AAA's right now, just publishing the battery voltage once a minute and light sleep kicking in for the rest of the time. Looks like that might last about 6 hours...