I saw your same post on the off road section, usally better to just post on place.
If this is still for the Slash- get it in a stick pack.
I bought some ProMatch batteries for 2 Slashs I have. I had the battery bars and shrink wrap so instead of paying to get a stick pack I made them myself.
Looking back, I'll pay the $5 for the stick pack. My son and I run the Slashs in water and mud and soon mud, the stick packs are more watertight than a 6 side by side pack.
I couldn't get the shrink wrap to completely seal at the ends. It been years since I built a pack and forgot about that.
Neighbor bought the same batteries and had them assembled, really nicely done and much better seal though not water proof.