If that's your preference, you can. Keep in mind that you will have no real control over what happens to them once you check them in. To be fair, I don't think I've ever travelled where my baggage was TOTALLY lost, but I have had it sent somewhere else mistakenly and I'd hate to try and buy new gear or start smoking for a few days. It's annoying enough to have to buy toiletries and underwear and whatnot. Anything I want to be certain is under MY control goes in my carryon and that would include mods.
But, it's not PROHIBITED to put them in the checked luggage, although batteries certainly would be.
Anna