How much battery needed

[liderbug]

If I wanted to construct a solar powered ESP32-CAM - how much battery would I need to last all night? And has anyone already invented this wheel?
Thanks

[mikemoy]

All you need to know is how much current your device consumes. From there is just simple math to figure out how much battery you need.

[liderbug]

OK, so I've read that a ESP32-cam draws 180mAh. If I use a 30000ma solar battery bank (amazon $25) my math says 166 hours. https://www.youtube.com/watch?v=0uz-YrfaSO8 says by using 2 18650 batteries he get 24h+.

[ESP_igrr]

The current consumption of the board will depend on several factors:

• whether the board is in sleep mode (deep sleep or light sleep) or not
• whether the camera is working (streaming) all the time or just a frame once in a while
• whether the board is connected to Wi-Fi all the time or not
• and if it is connected to Wi-Fi, whether power management features (automatic light sleep, DFS) are enabled

The answers to this depend a lot on the use case and what software you are using.
For example, if the camera is not supposed to take any pictures during the night, you can probably run it off a relatively small battery.
If it needs to stream over Wi-Fi all the time, then the current consumption will indeed be close to the number you gave.

[alanesq]

You may find this video by Andreas Spiess interesting: https://www.youtube.com/watch?v=37kGva3NW8w&t=623s

BTW - he has done several videos on powering from batteries etc.