While searching for a DIY battery charger, I landed on this website. http://www.apartmenttherapy.com/make-your-own-batterypowered-u-100359
So my question is, is it possible? I have a 9V rechargeable battery and I wish to use it again for our project.
If the answer is yes, can I directly attach the so-called 9V USB battery charger to my Relay Card? This card requires an input of 9-12V DC.
Thanks in advance!
P.S. I don't want to waste materials since I'm running out of funds for our project. T.T