27F Optima battery sliding all over the place

My taco came with this from the previous owner. It's sitting on the OEM battery tray, but because of the irregular shape, and because the lip on the tray is way bigger than the base of the battery, it's sliding all over the place. In the photo you can see where the harness has been rubbing along the top edge of the battery.

I can't find jack in a battery box/cage/tray for a 27F. Any ideas where a 27F battery cage like the Pelfreybilt group 31 could be found? Here's the Pelfreybilt group 31 one http://www.pelfreybilt.com/product/battery-cage/ which looks sturdy... something like that would be ideal.

 

Stupid question but are your j bolts tight enough? Ive never had a problem and im running a 24f which is smaller in size then the stock 27f (like you)

 

You are missing the supplied spacer for the battery

 

I had a similar problem with lateral shift with a Northstar 27F battery using the stock tie-down. This aftermarket piece seems to have solved it.

 

Ah so that's what it is. Thanks! I guess I'll Optima.