I run the 3s 1500 in my 18 and the 4s is 2mm longer and about 7mm higher, you could use longer fasteners in the plastic dowel for the battery hold down...I could make it work, I have used the hyperion short can before on 3s and it lasted a lot longer than the Mamba ever did...and the 1515 was a mistake...the 1105 is plenty.....lol