How many grams of lithium ion do nikon d3400 camera batteries contain? Many

How many grams of lithium ion do nikon d3400 camera batteries contain? Many

Less than 8 grams.

I can't imagine a reason for wanting to know.

For air travel, FAA limits the watt-hr rating of the battery to under 100 W-hr per battery. Grams of Li is for Lithium metal batteries which your camera does NOT use.

It doesn't matter - all they'll do is count the number of batteries you have. As long as your spare(s) are wrapped so they can't discharge (I use small polythene bags), nobody'll worry about it.