help with this battery operated air pump and power supply

[beginner]

Hey guys thought you might be able to help me out with this one..  I've got myself an aerobed for camping trips which comes with a rechargeable pump - this pump can be charged from the AC adapter or operated directly from a 12v lighter adapter.  What it tells my I can't do is operate the pump when plugged into AC or damage may result..  I can't really figure out why they've done this but am looking for a workaround.

The car adapter outputs 12v and is rated to 6.6 amps, the wall adapter outputs 12v and is rated to 400mA.  Am I able to trick the pump into not damaging itself when operated from AC by just using a 12v adapter rated to 6.6 amps?

[amyk]

I can't really figure out why they've done this but am looking for a workaround.

Cost reduction. An 80W power supply is a lot more expensive (and probably much bulkier) than a 4.8W one.

The damage they refer to is likely to overloading the adapter. Using a power supply rated for 80W at 12V should be fine.

[beginner]

I can't really figure out why they've done this but am looking for a workaround.

Cost reduction. An 80W power supply is a lot more expensive (and probably much bulkier) than a 4.8W one.

The damage they refer to is likely to overloading the adapter. Using a power supply rated for 80W at 12V should be fine.

too easy, thanks.

[NiHaoMike]

Adding a series 350mA or so PTC is one cheap way to solve the problem. Still costs too much for production, of course.