Check this thread out on The Samba,
http://www.thesamba.com/vw/forum/viewtopic.php?t=412499&highlight=microwave
There are several other good threads about this.

Ryan

On Thu, Sep 9, 2010 at 9:42 PM, Paul and Catherine Lemiuex <
catherinelemiuex@gmail.com> wrote:

> We need to install a microwave oven in order to sterilize medical supplies
> so we can continue camping in our 1990 Westy.   Having trouble finding a
> microwave that will work with a second battery and inverter.  Does anyone
> have any experience, suggestions or comments?
>
> thank you,
> catherinelemiuex@gmail.com