Electrical Isolation
- Darton
In this page, methods of keeping a battery module electrically isolated from the rest of the car will be discussed.
Information found about electrical isolation can be summed up with the following:
Keep live wires away from locations where they can make contact with other components and/or hands
Any exposed conductors should not be connected to the electrical system
Keep wires from fraying/leaking
In general, keep a layer of insulating material between conductors
Ensure that if a metal object will not short out what you are working on if it isropped
The regulations state that for our battery module,
Here are some pieces of practical knowledge I have gathered from the MSXIV documentation
Wires:
Wiring runs for voltage taps should be kept as short and bound together as much as possible to minimize wires rubbing and the possibility that the insulation will wear
Wires should have some form of strain relief to keep them from wearing, e.g. rubbery glue, as done in Wire Guide Under PCB Module - Mechanical - Confluence (atlassian.net).
Tip from MSXIV: If you’re doing right-angle crimps, use https://www.digikey.ca/en/products/detail/te-connectivity-amp-connectors/61481-1/294358
To be avoided
A thin layer of acetal should be placed over the potting compound used to pot batteries for further isolation
PCB Module isolation cover covers holes for voltage taps and the PCB that holds it
Connecting Modules in Series: Battery Module Rev 5 - Mechanical - Confluence (atlassian.net):
Disk springs made of stainless steel to keep the pieces pressed together
Hookup was not in contact with busbar
Fuses & Fuse Wires:
Fuse wires are used on large electric cars, like Tesla’s
It turns out that fuse wires are very complex, and quite unnecessary for MSXIV, due to a low current draw from each battery. They are also a nightmare to spot weld.
The bare minimum for fuses seems to be a fuse block:
Fuse and Power Distribution Blocks
Some more resources:
Byron Hopps / circuit design, mechanical/electrical integration