The insight battery pack is made up of 120 D cell NIMH batteries, grouped into packs of 6 cells. You can see that the air path for cooling the pack is not very open, therefor the cooling of the pack is not very agressive. The pack has a strip of thermal sensing material that is in intimate contact with each cell in the pack. The D cell subpacks are terminated with a large stainless steel nut that can handle the 100A output. This is the special part of the pack, as we have not found a D cell that has similar high current contacts, so cell replacement with new subpacks is not an option at this time. The civic packs up to 2005 are drop in replacements, so you could get one of those much more readily available used packs and rebuild your Insight pack with the civic subpacks which are direct replacements with a more robust cell structure. The 2006 and up civic packs are built differently and are not direct replacements.