This ESP32 comes with a battery holder at the back to provide power using a 18650 battery.
Scroll down to find the ESP32 at different stores and find the best price.
Aliexpress.com
Banggood.com
Ebay.com
£11.90
1 new
from £11.90
as of December 29, 2019 3:16 pm
Amazon.co.uk
$18.69
1 new
from $18.69
as of December 29, 2019 3:16 pm
Amazon.com