Ion battery falling off...any ideas?

New owner of an Ion, but must say a rubber strap to hold battery is such a horrible idea...but we're stuck with it.



Went to put Ion in the truck today and....no battery! Luckily it fell in the sled but way too easy coming off (I walked about 400 yards).



I currently have it taped in with electrical tape but wondering if anyone has a better idea???

Ion battery falling off...any ideas?