NWA sez it's just fine...
Sent NWA this question:
"Any issues with taking a small UPS(Uninteruptable Power Suppy, like you'd use for a home personal computer) to BKK from DTW? I'm planning on placing it in my checked luggage. Thanx in advance. --dlouise37"
..and the reply:
"Thank you for contacting NWA Online. There should be no problem checking
your ups.
Passengers should NOT pack medications, car keys, tickets, passports and
other legal documentation, valuable items such as jewelry, irreplaceable
items or cameras in checked luggage. For a complete listing of items
excluded from liability, please refer to the full text of the Northwest
Airlines Contract of Carriage, which can be viewed at any Northwest
airport counter or ticket office or it may be obtained online or by
writing to:
Northwest Airlines, Inc.
Customer Care
P.O. Box 1908
Minot, ND 58702"