Thinking I would be preventing rust, I added a battery mat to the bottom
of the battery well in my Vanagon.
http://www.batterymat.com/

However, it seems to actually have promoted rust in the bottom of the
battery tray.
My assessment is that the mat will collect moisture, so if you live in a
damper climate, this may prevent water from draining out of the battery
box, and actually hold the water in.

Something to consider if you are using one of these and live in a damper
area - like the Pacific Northwest.

Perhaps the thing to do is use this in conjunction with some sort of
tray, which would add more protection to the battery well.

Anyone have solutions or ideas?

regards,
Todd
'88 Westy