Last Updated: 1/22/24 Jason
This SOP provides a guide to safely manufacture and assemble battery segments of the GR23 electrical vehicle. Some of the information is compiled from the following sources.
Safety considerations, how they can occur, and how to avoid electrical accidents
Battery segment design
Necessary materials, tools, and equipment
Opening the battery shipment box
Handling li-ion cells
Storing the
Safety Considerations
Electrical shock & arc flash
There are two primary ways that direct current electrical injury can occur:
Body completing the loop in a high voltage circuit (touching positive and negative terminals of a high potential battery segment)
Non-insulated tool or a conductive material completes the circuit in a medium to high voltage circuit, generating an explosive arc that can produce intense heat
Electrical Insulating PPE
Referencing this Electrical Insulating PPE Guide and NFPA 70E PPE, working with electric potentials between 50-750VDC (GR23 battery segment is 110V max voltage, entire battery pack is 546V max voltage) requires:
As mentioned above, ensure that no non-insulated tools can fall across battery terminals or be accidentally used (remove all non-insulated tools that are magnetically attached above the workbench)
Workspace and ground should be covered with electrically insulating mats
No machining of metals should occur while battery segment terminals are exposed
Machining Fiberglass
Machining fiberglass can produce fine resin and glass particles that can be harmful if inhaled
Keep particles contained in CNC router enclosure
Use vacuum attachment
Wear masks
Wipe up particles often
Battery Segment Design
26s5p li-ion cells per segment comprised of Enepaq 1x5p Sony VTC6 modules
Necessary Materials, Tools, and Equipment
Electrical Insulating PPE
Referencing this Electrical Insulating PPE Guide and NFPA 70E PPE, working with electric potentials between 50-750VDC (GR23 battery segment is 110V max voltage, entire battery pack is 546V max voltage) requires:
electrically insulating class 00 gloves
nonconductive safety glasses
insulated tools
long sleeve shirt & pants
closed toed shoes
electrically insulating mat
arc-flash face shield
Drill bits & end mills for insulation panel machining
Epoxy for assembling panels
Wires & solder
Machining of insulation panels
Fixture panels, program cam, and set up tools on ShopBot Router referencing ShopBot SOP
Set up vacuum attachment and wear masks to minimize inhalation of fine fiberglass particles
File edges of panels to remove sharp glass fibers
Assembly of Enepaq modules within insulation
Insert modules with correct polarities and use epoxy to bond base and side panels of segment
Wear proper PPE (listed in safety considerations section); those without PPE should remain five feet away and connect modules together using bolts and busbars
Cover work surface and ground with electrically insulating mat and use insulated tools
Attach voltage taps under bolt heads using solder if necessary (onto copper washers)
Attach temperature sensing wires to module xr connector
Route wires through holes in top panel
Connect voltage taps carefully and avoid short circuiting any modules