The original battery enclosure was designed to fit two SLA batteries stacked. To secure the new battery without permanently modifying the battery enclosure or making a new one, I used high density foam spacers. These foam spacers are recycled from some packing material, so unfortunately, I do not know where or how to order these. However, they are included with batteries from BatteryStuff.com so they may be ordered from them. If anyone know what or how to order these easily please leave a comment!