Charge iPad 1 without wall charger
You might get a small trickle-charge by connecting to a Windows laptop, better if you don't run the iPad whilst doing so, but only a Mac is capable of recognising &amp; supplying the higher power requirement of an iPad.

Connected to any standard USB port on a PC, the device will claim it is not charging - though in practise it will eventually manage to charge it, it will be very slow.

Your best bet, if you don't own a Mac, is to buy a dedicated iPad charger.