You may use some of the universal adapters on the market. The power adapter needs to meet the following criteria:
1. Rated 45W or greater with an output voltage 18.5-20V (note: voltage >20V might be okay, but we haven't tested such laptop adapters);
2. With a plug that's either Lenovo's round-barrel type or its modern slim-rectangular cousin. If you aren't sure, please stop by a local laptop retailer to take a look at the adapter interface on Lenovo's demo laptops.
We have other PowerX models in development that are tailored to non-Lenovo laptop chargers. But they're further out on our production schedule. Stay tuned by following us on facebook.com/zettaly or twitter.com/zettaly, bookmarking our website www.zettaly.com, or pledging a dollar to get on our list of Kickstarter backers to receive updates.