Yeah get a converter to be safe.
Also try a USB charger I got the joytech tech pack so you can charge from a car or plug into your PC or Wii.
http://www.play.com/Games/DS/4-/3257095/Joytech-Tech-Pack-Black/Product.html
I managed to find one of these for £7.99 new.
I have UK version but what does it say on the back of the DS unit regarding power etc.
This is the back of my UK model.

EDIT
http://www.one4uni.com/product-info/44589-Joytech-DS-Lite-Tech-Pack
£9.99







