Two come to mind. One is "lighter plug" which is the automobile version.
Other is "coaxial power plug". I think.... hang on.

Coaxial :
http://brain.pan.e-merchant.com/8/5/...l_00563558.jpg

Coaxial to 9 volt clip (looks useful)

http://www.active123.com/310645-Coax...-Prodview.html

Lighter plug to coaxial adaptor:

http://www.aliexpress.com/item/Car-P...316299466.html



..
Christopher A. Young
Learn about Jesus
www.lds.org
..

On 9/12/2013 10:12 AM, Nate Nagel wrote:
what is the external battery pack connector called? I should know this
but my brain isn't helping, and I'm not coming up with the right search
keywords either. I have a few battery chargers for rechargeable
batteries; rather than using a wall wart for each I was going to take
12VDC from my UPS since the chargers all need to be plugged into the UPS
when in use anyway.

thanks

Nate