Here's a handy mod I did to my car, after wrestling with the battery brackets several times.
I sawed off and discarded the lower half of the battery bracket.
The battery is actually retained by the plastic clamp at the bottom, which is held down by a bolt.
A secondary guard bracket screws to the fender on the right, and is bolted to the air filter container on the left, and (originally) also to the bottom bolt.
This arrangement requires you to first unplug and remove the windshieldwasher bottle, then unfasten and remove the Air filter contraption, before finally getting at the battery.
Since
this is too ridiculous to even believe, I made an assessment of the purpose and function of the complex bracket, and sawed it in half, discarding the lower piece.
The upper portion still bolts to the filter, and is screwed at the other end to the fender. It performs the same function as before, acting as a safety to prevent the battery from being thrown out of its position (during a rough ride or an accident we suppose).
Any force strong enough to dislodge the battery and burst the retainer would cause worries far beyond that of the battery dislodging or getting broken, so I was not worried about some loss of strength regarding this extra bracket.
(This bracket doesn't even sit on the battery, so it won't hold it from coming loose from the lower retaining clamp anyway.)
Now I can remove the battery without having to pull apart the air filter section too.
Picture looking down into crack beside battery under windshieldwasher, showing sawed off part of bracket. Below this you can see the plastic clamp which actually holds the battery.