You have to be careful with them. If the 5150 is not listed as compatible, then you need to more research. (ask them).

There's no igo products available for the 600m, for example, and they've told me they don't intend to make them. I had to buy the small (credit-card sized) targus adaptor for air use, and it only runs the 600m in low power mode. Dell must have some proprietary stuff in their power adaptor for the 600m. The notebook bios can sense when you aren't using the normal a/c adaptor.

-David