Ethernet Shield Power Consumption

Hello all,

I'm building a project which needs to be able to run for as long as possible on a battery. I am running my Arduino with an Ethernet Shield.

I'm finding that in total the boards are drawing around 180mA - I was hoping to keep this below 100mA. I tested the Arduino board on it's own and it appears to only draw around 30mA.

So, it looks as though the Ethernet Shield is responsible for 150mA of current draw. Has anyone else found this? And if so, has anyone found a way to reduce the power consumption of the module? I was wondering if there was a way to modify the ethernet library to eliminate the indicator LEDs or something similar - every mA counts :D

Thanks to all in advance.

Which Ethernet shield are you using? There are versions built on the Wiznet and Xport modules, and one that uses the Microchip ENC28J60.

It's not very surprising that an Ethernet module would draw 150mA, since they're used in wired applications where power is usually handy. I think the LEDs are completely controlled internally in the case of the Wiznet module, but I'm not sure.

You could probably save a small amount of power by going with a switching regulator for 3.3V (although it could be dicey, for such a small current).

I would expect the ENC28J60 solution to be lower power. It might not be, but it's worth checking into. It's also available in kit form, so you can build it without the LEDs to save that energy. But also check to make sure it can do what you need: there are some significant differences in capabilities among the three solutions.

Finally, consider the possibility of using Power Over Ethernet instead of batteries. That might be cheaper and simpler than making the system more battery-friendly.


The W5100 chip alone pulls 150mA so you are not going to do any better than that if you use that chip.

Thanks for the help guys. I am using the w5100 shield. If the IC draws 150mA itself then that must explain it.

Thanks again for the prompt assistance!