12 volt power supply
 

I am thinking of installing a wheelchair lift in the back of my 2006 Odyssey
for occasional use. That would enable me to easily put my father's power
chair in the back of the minivan once in a while. These things take about
20 amps. There are 3 12 volt (10 amp) power supplies in the minivan, and
rather than permanently installing a wire to the battery as is recommended,
since the lift will only be used once in a while, I was thinking of making a
connector so I could connect all 3 power adapters already installed by the
factory to the lift when I use it. I presume that 3 times 10 amps will give
me 30 amps which is 10 more than it needs. Not being an electronics genius,
anyone knows if there is a problem with my idea? Thanks.