Lithium Battery for Laptop as Carryon
 

Are there going to be any issues about carrying on a new extra lithium battery for a laptop from US to Lisbon? I'll have a laptop and an iPad as well. Does the new battery need to be unboxed? I assume just put it in a tray at security like a laptop?

You'll be fine. In fact, lithium batteries must be carried on and not checked. All the news that's fit to print: http://safetravel.dot.gov/tips.html.

Place it in a container or plastic bag so the terminals don't come in contact with any metal objects.

The battery should not be loose, it should have whatever protective cap it came with attached.

The basic problem is that lithium-ion batteries have all their contacts close together and they have a sufficiently low internal resistance that shorting those contacts is a bad thing.

That's why unprotected lithium-ion batteries are completely prohibited as checked luggage and in general they should always be capped if they aren't in something meant for them.

While I've never carried a battery of that size anywhere other than in my laptop I normally fly with extra lithium-ion batteries. They simply are tossed in my camera bag with their caps in place. An x-ray guy in PVG got puzzled once, whether it was that or the box of AAs I don't know. I showed the security guy all the batteries, he was happy.

It is brand new still in the cardboard packaging. Are they going to want the packaging removed?

They may want to open it to swab it, but I don't think you will have a problem.

I almost always have a spare in my laptop bag that goes through X-ray. I use a wide rubber band to cover the contacts as it tends to stay in place better than the original shipping caps. I do keep it in a pocket by itself as well. Consumer LiON batteries should all have internal short circuit and temperature runaway protection so it's unlikely they would actually combust but on some batteries those safeties are sacrificial which could leave you with a brick it they tripped.

The only time I ever recall anything being said about batteries was in Frankfurt when I was asked if I had more then five batteries, I didn't and no one looked the verify.

Cheers

I had in my bag a very big Li ion battery, checked in and all good. But rules says you cannot do it.