Can I use my Nexus7 charger to charge my Android phone? The Nexus charger has an OP Amp rating of 2A. The charger that comes with the phone has an OP Amp rating of 1A. Both have the same voltage. IP voltage is 100-250 V for both.

I googled and came across various posts saying how Li-ion batteries are smarter and how the phone will only draw as much power as it needs, and not more. 

So essentially, the phone takes what it needs, and the charger is capable, but doesnt force its rated voltage on the device. Is this correct way of putting it?

Will it damage the battery in anyway? Or the charging circuit?
In short: yes, you can use your Nexus7 charger to charge your Android phone. If the connectors are compatible, it will work without problems.

I always use a single 2A USB charger for every phone, tablet and ereader that I have at home, and also for the Raspberry PI.