Loss of 4X4

The wife was plowing today and got my 700 stuck I came home after dark and tried to un-stuck it when I turned on the lights the speedo started blinking (low battery) and I had no 4X4 in forward or reverse, little red light on 4X4 selector went out as well, when I turned the lights off 4X4 was good to go, little red light came back on ….question is does the front end magnets need that much power to engage the 4X4?? Time for a new battery anyway but this has me wondering how much power does that magnet use?