M939 exterior battery box battery fitment

[MidnightDuramax]

I am trying to find out what other batteries other than the originals will fit in the new box. I have tried searching and cant find to much about them. Any help and maybe some pics of everyone's set ups would be great. Thanks

 

[wsucougarx]

Are you looking at the M939 Battery Relocation Kit? The box hold two plastic battery boxes that are identical in size to the M818 and M35A2. Since you've got an M818 you can use that for size. If you use anything smaller than the military ones, it's a good idea to shore it up with 2x4 pieces or make a bracket of some sort. This will keep the batteries from flopping if you're an off roader. I have the Optima's in one truck with the military battery tray adapters.

 

[MyothersanM1]

I used Costco Group 34's. Here's a pic of the set up. The numbers scribbled on the 2X4's ans 2X6's are their length measurements in inches.