5V USB Power Bank with a 2s2p cell config.

[jahod]

Hello!
Anybody seen a 5V USB Power Bank with a 2s2p (2 series, 2 paralell) cell configuration?

My idea is to make an 8.4V output connector (to power my camera) while at the same time maintain the 5V connectivity and charging capabilities.

Thx!

 

[Bunnykiller]

never "seen" one but Ive made a couple for RC applications..

 

[suprtrkr]

I wouldn't know where to buy one, but it shouldn't be too hard to make. If that's what you want, I think I'd start with a pair of 2S packs that already offer a separate charging plug splitting the cells for a "balanced" charger; and then just parallel them.

 

[jahod]

I know, but i needed something simple.

Have Sony A7s and the original NP-FW50 batt. lasts like an hour or so.

The idea was to use USB power bank and tweak an 5V to 7.4 V step-up power regulator to power my camera from any 5V source.

Some dude on a forum said its stupid to make 5V from LiPol cell (power bank) and then convert it back to 7.4 V to power camera. He said i risk a lot by having a lot of electronics between the camera and power source. Btw. camera costs cca $2000.

He said: get a cheap power bank with any configuration giving double LiPol cell voltage and just open the bank and make a output cable to power your camera directly from the cells. You risk little, while preserving the functionality of the powerbank (charging from USB is a relly nice thing for me)

Im a pro cameraman and i need solution that doesn't cost a fortune (need like 3x10Ah for a pro shooting day), is easily obtainable (no pro electronics know-how needed) and works reliably.

There is a a7s external power bank (8.4V) for $180. I suspect it being a $20 batt. pack with a couple of circuits.

Varavon a7S Battery Package BAT A7S SET B&H Photo Video

 

[Bunnykiller]

okay... now I see where you are going with this... I was under the impression you needed 8.4V supply for the camera and a 5V output... going from 5V to 8.4 throws a few more circuits into the mix, and charging 8.4 from a 5V source is also another circuit. Probably be more cost effective to buy the pre made unit instead of designing and "prototyping" a custom unit.