The web page provides conflicting information (see this statement further down the page about batteries in devices):
Portable electronic devices containing cells or batteries (including lithium) and spares for these devices intended for personal use:
For lithium-ion batteries, a maximum of 2, not exceeding 160 Wh each, are allowed in carry-on bag with airline approval
I'm going to take a liberal interpretation as you are and carry a printout of the website with me.
Thanks!