In article >, jim evans wrote:
>
> I've never seen this before. My battery has built up a lot of
> corrosion, but under the hold-down. Not on the terminals.
>
> http://tinyurl.com/v5xr9
>
> What would cause a battery to corrode in this odd location, but not at
> the terminals?

I've seen it before... Looks like a mazda hold down. It's not the battery
corroding but the hold down itself. If you remove it you should find
that the battery is fine.