Small update: The layout and position of the batteries and HV junction box has been bothering me. With the existing design, there’s a huge amount of unused space in the mid-engine bay, frunk and boot and in reality some consolidation was needed. Last Friday evening I put the thinking cap on and quickly starting ripping out many weeks’ worth of work to review the design. I’m so pleased I did as the revised solution works so much better in space efficiency and technical terms. Here’s a summary:
• The bulky HV junction box is now mounted inside the mid-engine bay. It hovers above the drive unit on two 25mm aluminium box sections and is secured to the car’s frame rails. This is a major improvement electrically too. It means I don’t need to modify the Chevy Volt BMS harness at all, the battery HV cables are a fraction of the length making them safer, and the drive unit can connect directly to the HV box without extending its cables.
• The small and medium battery modules are now be mounted in the boot – they just about fit with the use of some custom brackets and rubber bases. In time this may change again as there is space for them to hang under the boot.
Presently I don’t have the inclination to do the fabrication work. It’s something I can come back to if it bothers me, but I doubt it will. It means the boot can now be used for two batteries and most electrical services including LV junction box, BMS junction box and LV bulkhead connectors that run to the front of the car for the charger integration and DCDC communications.
• The frunk is now completely empty and free for luggage once again – back to OEM. The charger will remain behind the front bumper and the DCDC in the fuel tank area – perfect locations for these items on the Porsche 986.