Contain, protect and support the high voltage battery, the HV components and the LV components, and mount them to the frame.
A welded 6061 aluminium container on a tower layout: battery segments at the base, HV and LV compartments above and forward. Ten load-based welded mounts attach it to the frame.
Designed around the battery layout, for serviceability first, then tuned for stiffness and lightness, with ease of manufacturing kept in mind. Load-based mounting was chosen over corner-based because it lets the ten required points go where they are serviceable rather than where the corners are.
Rule F.10.2-3: floor minimum 3.2 mm (0.126 in), walls minimum 2.3 mm (0.09 in), internal fasteners equivalent in strength to a welded joint, segment structure must prevent 40 g forward, aft, left and right and 20 g up and down. Rule F.10.5-8: every attachment point including brackets, backing plates and inserts must withstand 15 kN minimum in any direction. Perforated area on each segment side wall is capped at 25% of that section, sized by the fan speed and airflow the cells need.
Segment structure validated by hand using Roark's formulas for a plate under uniform pressure. Fore/aft: 600 lbf segment force over 6 x 20.25 in gives 4.938 psi, sigma_max 5.75 ksi, sigma_center 2.87 ksi, y_max 0.00693 in, FoS 2.78. Lateral: 600 lbf over 6 x 2.88 in gives 34.72 psi, sigma_max 9.17 ksi, y_max 0.00349 in, FoS 1.75. Down: 300 lbf over 20.25 x 2.88 in gives 5.144 psi, sigma_max 0.833 ksi, FoS 19.2. Load-bearing column structural equivalency calculated with I = A*t^2/12 for the mounting tabs, side wall and front wall cross sections.
Walls waterjet, then welded on a jigging table with aluminium cube jigs. Mounts milled on the CNC and welded to the side walls. Warping is managed with strong heat sinks and fixtures, tight fit-up and tacking, clamping and tacking all corners before committing, and a stitch or skip weld pattern to distribute heat.
6061-T6 aluminium (16 ksi maximum stress, 9.7e6 psi modulus). Floor 0.16 in, external walls 0.125 in, internal walls 0.125 in, lid 0.125 in. Nomex YT510 paper for internal safety barriers. Waterproof material lining the outside for the rain test.
None recorded. This part has no entry in Knowledge_Transfer/Issue Logging/Fault Vault.xlsx, in either Issue Log.xlsx, in CR22/Issue Tracking/Shakedown 7-15-23.xlsx, or in any design review issue list found in CrimsonStorage or Box.
31.23 lb without mounts, 33.07 lb assembled including 1.8 lb of mounts. From the cost report drawings and CAD: CAD mass, CR26E master assembly: 7.495 lb (3.400 kg). CG at X 60.77 in, Y 0.03 in, Z 6.00 in in vehicle coordinates. (CAD component: CR26E Accumulator Container) Source: SolidWorks mass model exports: CR22 (5 May 2024), CR25 (4 Jul 2025), CR26I (30 Jul 2025), CR26E (22 Mar 2026) Quantity per car, as costed: 1
Nothing in CrimsonStorage covers these yet.