led - Is it practical to build a wearable project that draws 9A @ 12V?

When plugged into wall warts, the flexible LED strips I want to make into a wearable display draw 3A @ 12V per 5m.

To do a 30 x 15 pixel display that's 15m, or, 9A @ 12V running around my body. Is this prima-facie unsafe? If it's not, am I going to need to carry the batteries around on a trolley?

I believe the LEDs will light at 9V and just not be as bright (which may be what I want, anyhow) and I'll be running PWM'd patterns so it won't be a 100% duty cycle but I'd at least like to establish a lower bound.