# What happens when you overload the 5V pin on Zero W

I am trying to work out what will happen if I power too many NeoPixels from the 5V pin on a Zero.

I understand from the Uberguide that this is the calculation required to work out the power draw:

To estimate power supply needs, multiply the number of pixels by 20, then divide the result by 1,000 for the “rule of thumb” power supply rating in Amps. Or use 60 (instead of 20) if you want to guarantee an absolute margin of safety for all

And I see here that there is no polyfuse in the Pi Zero. And I understand from this guide how to work out power consumption of the Pi by itself.

So, when too many NeoPixels are connected, is the Pi damaged permanently? Does something short, or will the lights fail gracefully?

Any help or good links appreciated.

• why are you even thinking of using the Pi as a power supply? ... the RPi will act as an expensive fuse Apr 27, 2021 at 22:05
• Well 12 LEDs have worked without issue, 24 probably will with a 3a power supply right? 24 X 0.06 = 1.44 amps. But more? So expensive fuse then? No subtler woes first? Apr 27, 2021 at 22:29