I’ve brought some WiFi cameras to run in bird boxes but the battery life on them aren’t very good at all. I’ve tried running them from battery power banks but they switch off after the cameras have reached full charge. So I’ve now order some a23 12volt batteries, will run x 2 side by side with a step down regulator to 5 volts 300mah. My question is how long would they last? A bit more info of the camera, it has a 300mAh battery installed, says in the instructions that it’s DC 5v and has a working time of roughly 100 minutes. I understand the batteries I’ve ordered are the GP Super 23a 12v which from wiki stats 55mAh each which I’ll run in parallel. I’m not electrically aware so hope I’m on the right track.. Thank you!
Assuming two A23 batteries in parallel at \$12 V\$, the charge available is about \$110mAh\$ ( \$55 mAh\$ each). So, converting the \$12 V\$ to \$5 V\$ with average efficiency, the capacity will be equivalent to \$220 mAh\$ at \$5 V\$. So, it would last about 220/330 hours or about 40 minutes.