Portable Power Bank for LED Strip

I have a 4.5v LED strip 14.5watts (unknown amp draw; maybe 3amp) 30 LED 5050 per meter that runs off 3 AA Alkaline batteries. It runs fine for several hours (with the AAs) which is great but Id like to hook it up to a small power bank. I pulled out an old old power bank of 2200mAh 5v 1A output thats been sitting for some time without a charge. I spliced some wires of a USB connector and connected it to the strip light which ran for about 45 minutes before the lights went out. 

It worked for a little bit but my main question is that can I hook up a larger battery of 5500mAh that outputs 2.1A 5v to the strip to make it last longer; looking for several hours of power before it shuts off. The battery I used was so old maybe it lost some its 'magic" over time sitting in the drawer or because I am not getting the amps needed across the LEDs or maybe I was loosing voltage as the juice ran out. I'm not a pro at electrical stuff but I am a quick learner and any advice would be appreciated.

 

Thanks in advance

 

james

Edit: I did charge the old USB battery bank before trying to charge the LEDs

Hi,

It would be good to be sure about the ampere rating of your LED strip just to be safe. A much larger power source would be ideal if you want it to last longer. But again, just for safety, it should not burn the LEDs. https://learn.adafruit.com/rgb-led-strips/current-draw

i think xiaomi power banks is very amazing..I recommend the 2c model... xiaomi products are high quality and this power bank price is very Affordable..energizer power bank is too very good.. if you buy energizer power bank i recommend the UE20022 

Powerbank is a practical device and many brands are currently available in the market, including Xiaomi and Energizer brands.