# Combine 2 outputs from a single powerbank to increase current for driving leds and controller

I want to power a led matrix of 256 leds and my controller on the road. I calculated an approximation of the required current for the leds at 5.1A and the controller at 0.1A making 5.2A @5v together, though I think it will be lower depending on the animations.

I happen to have a 13600 mAh powerbank from Xiaomi lying around which supports quick charge through 2 micro usb outputs. 2.4A @ 5v.

I was thinking if I could combine these in parallel to increase current that would make 4.8A. Now that is slightly less but I could just dim the leds a little bit to make up for that last little bit.

Do you think that would be possible? I came up with the following circuit but as a starting embedded software engineer my experience is still limited so I might be missing something.

Basically, I just want to put the outputs in parallel and have a diode to protect against current flowing back into an output from another output and use a capacitor for peaks.

• 5120 mAH is not a current, it is a measure of energy. What is the current required for load and controller? You are mixing battery capacity and current as though they are the same Dec 9, 2017 at 13:45
• Ah my bad, the numbers were correct but I named it improperly. Required current for leds and controller is 5120mA. I edited the main post. Dec 9, 2017 at 14:03
• Overall, your general concept seems plausible, but the loss through the diodes will drop the voltage from 5 to maybe 4 or 4.3 depending on diode selection. This will likely be too low for your needs Dec 9, 2017 at 14:42