Wanting to improve my portraits, I invested a few months back in 2 off-camera flashes, 2 radio receivers and 1 radio transmitter. For all of that, I need 2*4 + 2*2 + 2 = 14 batteries (eneloop) for the setup to work and 10 more to replace failing batteries during the shooting session (about 2-3 hours long). So after the shooting, I need to recharge 24 batteries, which is beginning to be boring, but still manageable.
Now, I would like to add a third flash (and its radio reciever) to have more options regarding lighting setup. It will add 10 more batteries into the equation.
I also have the project to add small led panels close to the flashes, in order to provide a constant source of light. That will help me to better visualize the effect that each flash will produce. With 2 to 4 batteries per led panel, it will add between 12 to 24 more batteries to my collection (taking into account back-up batteries).
As you can imagine, managing about 50 batteries is going to be time-consuming and probably quite maddening.
I am wondering if I could use regular power bank to replace the flashes batteries and the led panel batteries (so I will be left with the 8 batteries required by my 1 radio transmitter and 3 radio receivers).
My analysis of the situation : each flash requires 4 AA batteries. 1 AA battery is 2500mah/1.2V, so in total about 5V and 10000 mah. Many power banks could deliver 5V with capacity over 10000mah. The main issue is probably amps and cycle time : the flash require about 5-6 amps to have a correct recycling time (about 3 sec), so the power bank will need to have an output of about 25W. After a brief market review, most cheap power bank have only an output of 5 to 10W, but some are promoting 45 to 60W (5V). For example, Xiaomi says that one of its 20000mah power bank model can provide 5V/5.4A (using its 3 outputs), so a little more than 25W (about $50).
Can I use regular (and cheap) USB power bank to optimize power management? Are there other (cheap) alternatives? How do you manage it?
I have looked at "serious" power bank (Godox propac for example), but they are a little expensive and heavy.
Regarding possible DIY solution and my experience with electronics, it has been a few years since I have soldered something on a pcb, but I could probably still manage it.
An important constraint is to have a "transportable" mini-studio. I would like to still be able to carry it around in two (big) bags.
Thanks in advance.