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Power supply: AAA batteries, rechargeable accumultors...

PostPosted: Thu Aug 27, 2015 10:31 am
by AlexPilk
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 :)

Re: Power supply: AAA batteries, rechargeable accumultors...

PostPosted: Thu Aug 27, 2015 4:45 pm
by Barnabybear
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.

Re: Power supply: AAA batteries, rechargeable accumultors...

PostPosted: Fri Aug 28, 2015 6:00 am
by trackerj

Re: Power supply: AAA batteries, rechargeable accumultors...

PostPosted: Sat Aug 29, 2015 1:56 pm
by torntrousers
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...